Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Cowpea is widely grown in the humid tropics as staple and is largely affected by genotype by environment interaction (GEI). Data obtained from field trials were subjected to genotype (G) by environment (E) interaction (GEI Biplot) analysis and was applied to examine the nature and magnitude of GEI and quantify their effects on cowpea performance in seven experimental trials in a rainforest and derived savanna agroecologies of south-west Nigeria. Results showed that genotype x environment interactions effects were significant on cowpea growth and yield characters. The differential performance of cowpea varieties as early- and late- rainy season crops at both locations were attributable to variability in the soil, weather and biotic factors of the test environments. Determination of winning genotype(s) and yield ranking across environments showed that cowpea varieties depicted differential performance for the test environments and hence the interaction was crossover type. Varieties IT97K-568-18, IT97K-568-18 and Oloyin Brown are high yielding while IT96D-610 and IT98K-205-8 are poor. Oloyin Brown and IT98K-573-2-1 won in Akure 1, 2, 3 and 4 and Ado 1 while IT97K-568-18 won in Ado 2 and Akure 5. IT96D-610 and IT98K-205-8 did not win in any environment. The best performing varieties, Oloyin Brown, IT97K-568-18 and IT98K-573-2-1 combined both high yield and stable performance across test environments and were characterized as ideal genotypes while most unstable variety, IT96D-610, performed poorly in test environments. It is concluded that Ado-Ekiti was best for the late rainy while Akure location was best for early rainy season cropping.
Germination percentage and growing behavior of Salix tetrasperma (Willow) as ...Innspub Net
ย
Propagation through branch cuttings is one of the best methods to produced tree nursery the yield of the tree produced from a cutting can be higher then a tree produced from seedlings, the conditions provided to them are important factor for getting good results. The aim of this study was to find the best size of cuttings for establishment of nursery and also to compare their performance in open air or in artificial conditions under plastic sheets cuttings of 2 inches, 4 and 6 of Salix tetrasperma were raised in plastic bags of size 3x7 their were three treatments with 25 bags in each and replicated 4 times. The data on sprouting percentage, plant height, root development etc was recorded after every two weeks. The data thus collected was analyzed statically using randomized complete block design. Result showed that cutting of 2 inches has high sprouting percentage and growth behavior as compared to other cuttings. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Genotype x Environment Interaction and Grain Yield Stability of Maize (Zea ma...Premier Publishers
ย
Testing of genotypes in multi-environments is an important to estimate genotype x environment interaction (GEI) and identify stable genotypes with superior performance. The study was to evaluate different maize hybrids at multi-environments as well as to identify high yielding and stable maize hybrids. Twenty maize hybrids were tested across eight environments in a randomized complete block design in the 2015 cropping season. Combined analysis of variance and AMMI analysis showed that genotype, environment and GEI effect were highly significant (p < 0. 01) for grain yield. Genotype, environment and GEI explained 6.62, 84.87 and 4.50% of the total experimental variations, indicating the importance of environment for variations in grain yield. Mean grain yield of tested hybrids ranged from 4.98 t ha-1 in G2 to 7.51 t ha-1 in G16. As evident from significant GEI, performances of the hybrids were inconsistent across environments indicated that suitable to specific environment. Based on AMMI stability value and mean ranking of GGE biplot indicated that G18 (BH 546) had high grain yield (7.16 t ha-1) and more stable across tested environments. This study identified maize hybrids with high grain yield and stable across environments that need to be further validated for possible new maize variety release and or the newly released hybrid is used for possible commercial production.
Assessment of genotype by environment interactions and grainAlexander Decker
ย
The document discusses a study that evaluated 100 extra-early maize hybrids across three environments in Ghana to determine the presence and effects of genotype by environment interactions (GxE) on grain yield. The study found significant effects of genotype and environment on grain yield, but GxE was not significant. Using GGE biplot methodology, five hybrids - TZEEI 8 x TZEEI 51, TZEEI 5 x TZEEI 53, TZEEI 21 x TZEEI 39, TZEEI 27 x TZEEI 36, and TZEEI 4 x TZEEI 6 - were identified as high yielding and stable across environments. In contrast, five other
Ecophysiological Yield Components In Wheat Cultivars Under Variable Phosphoru...Agriculture Journal IJOEAR
ย
Abstractโ Effects of P deficiency and interactions Cultivar x P available, on wheat yield and ecophysiological components were analysed, considering that the grain number m-2 is the product of the length of spike growth period, crop growth rate during this phase, the proportion of growth for spikes (partitioning) and spike fertility (grain number produced per unit of spike dry weight). Four cultivars with different strategy to generate yield (i.e. combinations of ecophysiological yield components) were compared with and without P fertilization, during two years in Azul, Buenos Aires, Argentina. The soil was moderately P deficient (7-9 mg P kg-1 soil) and P fertilization treatments (50 kg P ha-1) were established at sowing. P deficiencies affected yield and most of its components, the exceptions were: partitioning to spike, spike growth period and radiation use efficiency. The interaction Cultivar x P fertilization was not significant in all cases. The lack of interaction between cultivar and P level suggest that improvements in any crop physiological component will express in both, moderately deficiencies or high P environment.
Study of Genotype x Environment Interaction for Sweetpotato Tuber Yield and R...Premier Publishers
ย
The current study was aimed to understand the nature and magnitude of genotype x environment interaction (GEI) while determining yield performances and stability of 9 sweetpotato genotypes. Evaluations were done in three locations in Papua New Guinea over two seasons from 2016-2017 via GxE multi-location trials. Additive main effect and multiplicative interaction (AMMI) analysis revealed significant (P< 0.05) differences among the total treatment interaction (G, E and GEI) while GEI alone was non-significant for tuber yields. Combined analysis showed significant environmental effect on tuber yields, tuber number and gall mite while harvest index, tuber dry matter and scab disease were influenced by genotype main effect. Tuber yields varied from 5.0-13.5, 8.5-18.0 and 2.6-4.7 t/ha for marketable, total and dry tuber yield respectively. New genotypes generally outperformed local varieties in terms of yield and stability. Genotypes G5, G3 and G1 gave promising yield and stability across environments. GGE biplot identified two mega-environments and also tagged G6 as winning genotypes at Aiyamontena and Tambul while G2, G3 and G4 are ideal for Bubia. This indicates that analysis of GxE trials using AMMI/GGE model and auxiliary parameters is important to determine adaptability/stability to identify superior genotypes. Selected genotypes can be recommended for cultivation in specific test locations and similar environments. Tambul was considered as the most favourable environment for production of these genotypes. This study revealed that there is high degree of variation in tuber yields and related traits due to diverse environments and GEI, thus, further breeding and selection for high yield and widely adaptable varieties is necessary.
Nine groundnut varieties were tested across six environments in western Oromia, Ethiopia during 2013 main cropping season to evaluate the performance of groundnut varieties for kernel yield and their stability across environments. The varieties were arranged in randomized complete block design (RCBD) with three replications. Pooled analysis of variance for kernel yield showed significant (pโค0.01) differences among the varieties, environments and the genotype by environment interaction (GxE). Additive main effect and multiplicative interactions (AMMI) analysis showed highly significant (pโค0.01) differences for varieties, environments and their interaction on kernel yield. Similarly, the first and the second interaction principal component axis (IPCA1 and IPCA 2) were highly significant (pโค0.01) and explained 41.32 and 7.2% of the total GxE sum of squares, respectively. The environment, genotype and genotype by environment interaction accounted 14.7, 24.1 and 53.3% variations, respectively. This indicated the existence of considerable amounts of deferential response among the varieties to changes in growing environments and the deferential discriminating ability of the test environments. Shulamith and Bulki varieties showed the smallest genotype selection index (GSI) values and had the highest kernel yield and stability showing that these varieties had general adaptation in the tested environments. In the genotype and genotype by environment (GGE) biplot analysis, IPCA1 and IPCA 2 explained 63.5% and 22.4%, respectively, of genotype by environment interaction and made a total of 85.9%. GGE biplot analysis also confirmed Bulki and Shulamith varieties showed better stability and thus ideal varieties recommended for production in the test environments and similar agro-ecologies.
Yield Stability and Genotype ร Environment Interaction of Faba Bean (Vicia fa...Premier Publishers
ย
The present research was conducted to assess the effect of genotype ร environment interaction (GEI) on grain yield and determine yield stability of faba bean genotypes using 50 genotypes in randomized complete block design with three replications tested at Holetta, Watebecha Minjaro and Jeldu with and without lime application in 2017. The grain yield performances of genotypes were varied across environments which indicate the existence of GEI. The mean grain yields of genotypes were ranged between 51.16g (Wayu) and 96.40g (CS20DK) with an overall mean value of 78.02g/5plants. The AMMI ANOVA showed that environment, genotype and GEI contributed 58.05, 16.08 and 14.28% of total variation in grain yield, respectively. The significant differences among genotypes, environments and interaction effect of the two way interactions on grain yield showed the differential response of genotypes over locations and managements and the test environments were different each other. Based on mean grain yield, stability parameters from AMMI and GGE-biplot, Tumsa, Cool-0034, EH07015-7 and EKLS/CSR02019-2-4 were identified as the four most stable/relatively stable and productive genotypes whereas Wolki, Numan, EH09004-2 and CS20DK had high grain yield and dynamic response to environments. Therefore, this experiment has to be repeated for one more season for reliable recommendation.
Germination percentage and growing behavior of Salix tetrasperma (Willow) as ...Innspub Net
ย
Propagation through branch cuttings is one of the best methods to produced tree nursery the yield of the tree produced from a cutting can be higher then a tree produced from seedlings, the conditions provided to them are important factor for getting good results. The aim of this study was to find the best size of cuttings for establishment of nursery and also to compare their performance in open air or in artificial conditions under plastic sheets cuttings of 2 inches, 4 and 6 of Salix tetrasperma were raised in plastic bags of size 3x7 their were three treatments with 25 bags in each and replicated 4 times. The data on sprouting percentage, plant height, root development etc was recorded after every two weeks. The data thus collected was analyzed statically using randomized complete block design. Result showed that cutting of 2 inches has high sprouting percentage and growth behavior as compared to other cuttings. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Genotype x Environment Interaction and Grain Yield Stability of Maize (Zea ma...Premier Publishers
ย
Testing of genotypes in multi-environments is an important to estimate genotype x environment interaction (GEI) and identify stable genotypes with superior performance. The study was to evaluate different maize hybrids at multi-environments as well as to identify high yielding and stable maize hybrids. Twenty maize hybrids were tested across eight environments in a randomized complete block design in the 2015 cropping season. Combined analysis of variance and AMMI analysis showed that genotype, environment and GEI effect were highly significant (p < 0. 01) for grain yield. Genotype, environment and GEI explained 6.62, 84.87 and 4.50% of the total experimental variations, indicating the importance of environment for variations in grain yield. Mean grain yield of tested hybrids ranged from 4.98 t ha-1 in G2 to 7.51 t ha-1 in G16. As evident from significant GEI, performances of the hybrids were inconsistent across environments indicated that suitable to specific environment. Based on AMMI stability value and mean ranking of GGE biplot indicated that G18 (BH 546) had high grain yield (7.16 t ha-1) and more stable across tested environments. This study identified maize hybrids with high grain yield and stable across environments that need to be further validated for possible new maize variety release and or the newly released hybrid is used for possible commercial production.
Assessment of genotype by environment interactions and grainAlexander Decker
ย
The document discusses a study that evaluated 100 extra-early maize hybrids across three environments in Ghana to determine the presence and effects of genotype by environment interactions (GxE) on grain yield. The study found significant effects of genotype and environment on grain yield, but GxE was not significant. Using GGE biplot methodology, five hybrids - TZEEI 8 x TZEEI 51, TZEEI 5 x TZEEI 53, TZEEI 21 x TZEEI 39, TZEEI 27 x TZEEI 36, and TZEEI 4 x TZEEI 6 - were identified as high yielding and stable across environments. In contrast, five other
Ecophysiological Yield Components In Wheat Cultivars Under Variable Phosphoru...Agriculture Journal IJOEAR
ย
Abstractโ Effects of P deficiency and interactions Cultivar x P available, on wheat yield and ecophysiological components were analysed, considering that the grain number m-2 is the product of the length of spike growth period, crop growth rate during this phase, the proportion of growth for spikes (partitioning) and spike fertility (grain number produced per unit of spike dry weight). Four cultivars with different strategy to generate yield (i.e. combinations of ecophysiological yield components) were compared with and without P fertilization, during two years in Azul, Buenos Aires, Argentina. The soil was moderately P deficient (7-9 mg P kg-1 soil) and P fertilization treatments (50 kg P ha-1) were established at sowing. P deficiencies affected yield and most of its components, the exceptions were: partitioning to spike, spike growth period and radiation use efficiency. The interaction Cultivar x P fertilization was not significant in all cases. The lack of interaction between cultivar and P level suggest that improvements in any crop physiological component will express in both, moderately deficiencies or high P environment.
Study of Genotype x Environment Interaction for Sweetpotato Tuber Yield and R...Premier Publishers
ย
The current study was aimed to understand the nature and magnitude of genotype x environment interaction (GEI) while determining yield performances and stability of 9 sweetpotato genotypes. Evaluations were done in three locations in Papua New Guinea over two seasons from 2016-2017 via GxE multi-location trials. Additive main effect and multiplicative interaction (AMMI) analysis revealed significant (P< 0.05) differences among the total treatment interaction (G, E and GEI) while GEI alone was non-significant for tuber yields. Combined analysis showed significant environmental effect on tuber yields, tuber number and gall mite while harvest index, tuber dry matter and scab disease were influenced by genotype main effect. Tuber yields varied from 5.0-13.5, 8.5-18.0 and 2.6-4.7 t/ha for marketable, total and dry tuber yield respectively. New genotypes generally outperformed local varieties in terms of yield and stability. Genotypes G5, G3 and G1 gave promising yield and stability across environments. GGE biplot identified two mega-environments and also tagged G6 as winning genotypes at Aiyamontena and Tambul while G2, G3 and G4 are ideal for Bubia. This indicates that analysis of GxE trials using AMMI/GGE model and auxiliary parameters is important to determine adaptability/stability to identify superior genotypes. Selected genotypes can be recommended for cultivation in specific test locations and similar environments. Tambul was considered as the most favourable environment for production of these genotypes. This study revealed that there is high degree of variation in tuber yields and related traits due to diverse environments and GEI, thus, further breeding and selection for high yield and widely adaptable varieties is necessary.
Nine groundnut varieties were tested across six environments in western Oromia, Ethiopia during 2013 main cropping season to evaluate the performance of groundnut varieties for kernel yield and their stability across environments. The varieties were arranged in randomized complete block design (RCBD) with three replications. Pooled analysis of variance for kernel yield showed significant (pโค0.01) differences among the varieties, environments and the genotype by environment interaction (GxE). Additive main effect and multiplicative interactions (AMMI) analysis showed highly significant (pโค0.01) differences for varieties, environments and their interaction on kernel yield. Similarly, the first and the second interaction principal component axis (IPCA1 and IPCA 2) were highly significant (pโค0.01) and explained 41.32 and 7.2% of the total GxE sum of squares, respectively. The environment, genotype and genotype by environment interaction accounted 14.7, 24.1 and 53.3% variations, respectively. This indicated the existence of considerable amounts of deferential response among the varieties to changes in growing environments and the deferential discriminating ability of the test environments. Shulamith and Bulki varieties showed the smallest genotype selection index (GSI) values and had the highest kernel yield and stability showing that these varieties had general adaptation in the tested environments. In the genotype and genotype by environment (GGE) biplot analysis, IPCA1 and IPCA 2 explained 63.5% and 22.4%, respectively, of genotype by environment interaction and made a total of 85.9%. GGE biplot analysis also confirmed Bulki and Shulamith varieties showed better stability and thus ideal varieties recommended for production in the test environments and similar agro-ecologies.
Yield Stability and Genotype ร Environment Interaction of Faba Bean (Vicia fa...Premier Publishers
ย
The present research was conducted to assess the effect of genotype ร environment interaction (GEI) on grain yield and determine yield stability of faba bean genotypes using 50 genotypes in randomized complete block design with three replications tested at Holetta, Watebecha Minjaro and Jeldu with and without lime application in 2017. The grain yield performances of genotypes were varied across environments which indicate the existence of GEI. The mean grain yields of genotypes were ranged between 51.16g (Wayu) and 96.40g (CS20DK) with an overall mean value of 78.02g/5plants. The AMMI ANOVA showed that environment, genotype and GEI contributed 58.05, 16.08 and 14.28% of total variation in grain yield, respectively. The significant differences among genotypes, environments and interaction effect of the two way interactions on grain yield showed the differential response of genotypes over locations and managements and the test environments were different each other. Based on mean grain yield, stability parameters from AMMI and GGE-biplot, Tumsa, Cool-0034, EH07015-7 and EKLS/CSR02019-2-4 were identified as the four most stable/relatively stable and productive genotypes whereas Wolki, Numan, EH09004-2 and CS20DK had high grain yield and dynamic response to environments. Therefore, this experiment has to be repeated for one more season for reliable recommendation.
This document discusses a study that used mixed structural covariance analysis, path analysis, and crop modeling to evaluate variation in yield components and potential yield between high-latitude and mid-European spring wheat genotypes currently grown in Finland. The study aimed to identify optimal ideotypes for each region and assess their adaptation under future climate conditions. Key findings include:
1) Modern genotypes have significantly higher yield potential than older varieties, with mid-European varieties exceeding 5 tons per hectare even under non-optimal conditions.
2) Grains per ear, harvest index, and kernel weight were the most important factors determining yield potential based on path analysis.
3) Crop modeling suggests mid-European ideotypes could achieve over 5.1 tons per
Journal of The Earth Science and Climate Change is a peer reviewed academic journal that cater to the needs of Earth Scientists, farmers, extensive agents, researchers and students. This Open access journal publishes high quality articles following rigorous and standard review procedure.
11.genotype x environment interaction analysis of tef grown in southern ethio...Alexander Decker
ย
This document summarizes a study on genotype x environment interaction of tef varieties grown in southern Ethiopia. Twenty-two tef genotypes were evaluated across four locations over two years. Significant differences were found among genotypes and locations, and for the genotype x environment interaction. Analysis of variance and AMMI modeling revealed that the variety DZ-Cr-255 was the most stable and high-yielding across locations. The locations of Areka and Hossana showed similar interaction patterns and may represent good testing environments. The study provides information to guide tef breeding efforts in the region.
Association mapping identifies loci for canopy coverage in diverse soybean ge...Avjinder (Avi) Kaler
ย
Rapid establishment of canopy coverage decreases
soil evaporation relative to transpiration improves
water use efficiency and light interception, and increases
soybean competitiveness against weeds.
Genotype by environment interaction and stability of extra-early maize hybrid...IJEAB
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Maize (Zea mays L.) is the most important cereal crop produced in Ghana. However the change in environmental conditions, the expansion of maize to new agro-ecologies coupled with inadequate maize varieties available for the different environments affects yield improvement programmes in Ghana. Hence, the study is to investigate the influence of genotype by environment interaction on the maize hybrids and to identify stable and high yielding hybrids with superior agronomic for famers use in the country. The objectives of the study was to investigate the influence of genotype by environment interaction on the maize hybrids and to identify stable and high yielding hybrids with superior agronomic performance for famers use in Ghana. Thus, fifteen extra-early maize hybrids and three locally released checks were evaluated in a randomized complete block design with three replications in two locations in Ghana. The experiment was carried out at KNUST and Akomadan which represent the forest and forest transition zones of Ghana. Nine of the hybrids out of the fifteen hybrids evaluated produce above the average yield and the effect of genotype, location and genotype by location interaction was significant for grain yield. The GGE biplot used in this study revealed that TZEEI-1 x TZEEI-21, TZEEI-6 x TZEEI-21, TZEEI-15 x TZEEI-1 and TZEEI-29 x TZEEI-21 were high yielding and stable hybrids because they were closer to the ideal. The GGE biplot also identified Akomadan as the most ideal testing environment for these hybrids under irrigation.
Genotype by Environment Interaction of Full-sib Families of Maize Endosperms ...Premier Publishers
ย
The present study was conducted at the Teaching and Research Farms, Federal University of Agriculture, Makurdi and Research Farm, College of Agriculture, Lafia to evaluate the presence of genotype by environment interactions in a population of 300 FS families of three maize endosperms to ascertain their agronomic performance, yield and stability across environments. The experiment was laid out in a 10 ร 10 balanced lattice square design with three replications. Results from the GGE Biplot for mean grain yield performance showed the entry P93 (Popcorn) obtained the highest yield at Lafia while F5 (Field Corn) had the highest yield and thus the winning family for Makurdi. The entries S72, P98, P90, S20, P31, and P54 were the most stable with an above average performance and thus recommended. The significant Location by Entries interaction effects for grain yield explains that a promising genotype selected in one of these locations will not be suitable for production in the other locations in the same agro-ecological zone, however, P93 (Popcorn) and F5 (Field corn) recorded the highest yield for Lafia and Makurdi respectively. The identified stable or location specific families should be crossed in all possible combinations to complete Cycle 1 of the FS families in a recurrent selection programme.
Development of drought tolerant maize cultivars is prerequisite to achieving stable grain yield in
droughtโprone ecologies of Nigeriaโs Guinea savanna. However, success has been limited mainly due
to lack of maize genotypes that show clear differences in response to well defined moisture deficit
condition. Two sets of drought tolerant (DT) maize germplasm were evaluated under screenhouse and
field conditions between 1999 and 2002. In the screenhouse study, performances of the genotypes
were compared under well-watered condition and moisture deficit imposed at different growth stages.
Under field conditions, the first set comprising 11 accessions along with a check were evaluated for 4
growing seasons while the second set which comprised 3 DT varieties were evaluated along with 2
check varieties using monthly plantings between April and August of 2001 and 2002, respectively. In
the first set, post anthesis moisture deficit significantly reduced grain yield by 25 to 73.5% in the open
pollinated varieties (OPVs) and by 20 to 64% in the hybrids. Grain yield under field conditions ranged
from 2.48 to 3.49, 2.82 to 3.73 and 3.58 to 4.76 tons/ha-1 for 1999, 2000 and 2001 full growing seasons,
respectively, and 2.03 to 2.50 tons/ha-1 for 2000 late growing season. In the second set, pre and post
anthesis moisture deficits reduced grain yield by 77.6 and 95.8%, respectively, of well watered
condition while in the field, grain yields in the genotypes were highest for plantings made in April and
July (1.90 - 2.5 t/ha), lowest for August (0.7 -1.8 t/ha) when moisture deficit coincided with
reproductive phase. Yield stability exhibited under moisture deficit and on the field by 8522-2, Oba
super 2 and AK9943-DMRSR in the first set as well as DT-SR-Y C0 and DT-SR-W C0 in the second set,
indicates their suitability either as cultivars per se or as potential source of DT alleles for
development of DT maize varieties for Nigeriaโs savanna ecologies.
This document describes a study that used association mapping to identify genomic regions associated with canopy temperature (CT) in soybeans under drought conditions. The study evaluated 345 soybean accessions in three environments, measuring CT using aerial infrared imaging. 52 single nucleotide polymorphisms (SNPs) were significantly associated with normalized CT (nCT), tagging 34 genomic regions. Several of the identified regions contained genes related to drought tolerance functions like transpiration, water acquisition, and response to abscisic acid. Fifteen SNPs associated with nCT were also associated with canopy wilting. The study aims to identify genotypes and alleles that can be used in breeding programs to improve soybean drought tolerance.
Effect of storage methods of cassava planting materials on establishment and ...Innspub Net
ย
Cassava (Manihot esculenta Cruntz.) establishment depends on quality of planting materials. The experiment was done to determine the effects storage and variety on crop establishment and early growth vigour. Karembo and KME 4 varieties were stored in clamp under double shade (CUDS), horizontal under shade (HUS), vertical under shade (VUS) and horizontal under open ground (HOUG) as control for 16 weeks. Planting materials was sampled from each storage methods after every 4 weeks and taken to field to evaluate their sprouting ability, number of primary shoots formation, number of leaves, rate of leaf formation and early growth vigour. Data were subjected to ANOVA and means separated by LSD. Sprouting percentage at Kabete was 54.73 % while in Kiboko had 37.78 %. The results showed that Kabete had 1.60 number of primary shoots per plant compared to 1.04 of Kiboko. The results showed KME4 had higher sprouting than Karembo in both sites. This can be due to genetic difference among varieties. The rate of leaf formation at Kiboko was higher as compared to Kabete it could be contribute difference in temperature between locations. Thus, optimum temperature and relative humidity should be factored in cassava cuttings storage to avoid increased death of stored cuttings. In case of storage cassava cuttings, should be stored in clamp under double shade methods under low temperature and moderate RH.
Seasonal growth patterns of Arundo donax L. in the United States | IJAAR @sli...Innspub Net
ย
Giant reed (Arundo donax L.) has been extensively evaluated as a dedicated energy crop for biomass and biofuel production in southern Europe and the United States, with very favorable results. Current agronomic and biologic research on giant reed focuses on management practices, development of new cultivars, and determining differences among existing cultivars. Even though detailed information on the growth patterns of giant reed would assist in development of improved management practices, this information is not available in the United States. Therefore, the objective of this 2-year field study was to describe the seasonal growth patterns of giant reed in Alabama, United States. Changes in both plant height and biomass yield of giant reed with time were well described by a Gompertz function. The fastest growing period occurred at approximately 66 d after initiation of regrowth (mid-May), when the absolute maximum growth rate was of 0.045 m d-1 and 0.516mg ha-1 d-1. After mid-May, the rate of growth decreased until maturation at approximately 200 d after initiation of regrowth (mid- to late September). The observed maximum average plant height and biomass yield were 5.28 m and 48.56mg ha-1, respectively. Yield decreased following maturation up to 278 d after initiation (early to mid-December) of growth in spring, partly as a result of leaf loss, and was relatively stable thereafter.
Field experiments were conducted to investigate the variations in sixteen maize genotypes in relation to drought tolerance. The experimental set up was subjected to drought stress after five weeks of planting for three weeks before data on morphological and yield characters of maize genotypes were obtained for three cropping years. Plant height and grain yield of Bodija yellow maize were the highest overall. There was a significant difference among genotypes for drought stress resistance and Bodija yellow maize showed the most tolerance, while TZBR Comp 1 โ C1 S2 510 genotype was the least. First principal component axis (Prin 1) had the highest contribution to the variation of the morphological, yield and drought tolerance traits. Prin 1 was highly related to the morphological and yield characters more than to the drought resistance. Plant height was negatively and strongly correlated (p<0.01) with stem height, number of leaves, stem girth, leaf length, leaf width and week after planting, but negatively correlated with the drought resistance. Therefore, Bodija yellow maize should be considered as parent material in breeding for the development of drought tolerant traits in maize.
Seasonal Dynamics of Arbuscular Mycorrhizal Fungi, Glomalin and Soil Properti...ijtsrd
ย
To understand the ecological significance of arbuscular mycorrhizal fungal (AMF) associations in agroecosysytem, the host specific and seasonal dynamics of AMF and glomalin-related soil protein (GRSP) was investigated in agricultural fields of Nanded, Maharashtra State. Soil samples were collected from the rhizosphere of eight crop plants (Glycine max (L.) Merr., Saccharum officinarum L., Zea mays L., Cajanas cajan (L.) Millsp., Gossypium arboreum L., Triticum aestivum L., Sorghum vulgare Pers. and Cicer arietinum L.) in winter, summer and monsoon seasons respectively. Arbuscular mycorrhizal root infection and spore density of AMF peaked in monsoon and winter.The mean contents of total glomalin related soil proteins (T-GRSP) reached maximal values in summer. Spore density was highest in Zea mays L. Easily extractable glomalin related (EE-GRSP) and T-GRSP fractions were the highest in the rhizosphere of Cicer arietinum L. and Sorghum vulgare Pers. AMF root colonization and spore density was negatively correlated with K (P < 0.05; P < 0.01). T-GRSP fraction was positively correlated with edaphic factors (rhizosphere temperature, K and Fe content of soil) and negatively correlated with soil moisture (P < 0.01), AMF root colonization (P < 0.05) and spore density (P http://www.ijtsrd.com/biological-science/ecology/15727/seasonal-dynamics-of-arbuscular-mycorrhizal-fungi-glomalin-and-soil-properties-in-agroecosystems-of-nanded-district/ujwala-sheshrao-deepake
Genotype x environment interaction analysis of tef grown in southern ethiopia...Alexander Decker
ย
This document summarizes a study that evaluated 22 tef genotypes for grain yield performance across four locations in southern Ethiopia. Significant differences were found among genotypes and locations, and for the genotype x environment interaction. Analysis of variance and AMMI modeling were used to analyze the data. The study found that genotype DZ-Cr-255 was the most stable and high-yielding variety across locations. Areka and Hossana locations showed similar patterns of interaction and had higher average yields, indicating they may be better test environments. The first principal component axis from the AMMI analysis captured 48.7% of the genotype x environment interaction variance.
GGEBiplot analysis of genotype ร environment interaction in Agropyron interme...Innspub Net
ย
In order to identify genotypes of Agropyron intermedium with high forage yield and stability an experiment was carried out in the Research station of Kermanshah Iran.The 11 accessions were sown in a randomized complete block design with three replications under rainfed and irrigated conditions during 2013-21-014 cropping deasons. Combined analysis of variance indicated high significant differences for location, genotype and G ร E interaction (GEI) at 1% level of probability. Mean comparisons over environments introduced G4, G3 and G5 with maximum forage yield over rainfed and irrigated conditions. Minimum forage yield was attributed to genotype G1. GGEbiplot analysis exhibited that the first two principal components (PCA) resulted from GEI and genotype effect justified 99.37% of total variance in the data set. The four environments under investigation fell into two apparent groups: irrigated and rainfed. The presence of close associations among irrigated (E1 and E3) and rainfed (E2 and E4) conditions suggests that the same information about the genotypes could be obtained from fewer test environments, and hence the potential to reduce testing cost.The which-won-where pattern of GGEbiplot introduced genotypes G3 and G4 as stable with high forage yield for rainfed condition, while G5 was stable with high yield for irrigated condition. According to the comparison of the genotypes with the Ideal genotype accessions G4, G3 and G9 were more favorable than all the other genotypes. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Genetic control and heterosis depend directly on genetic divergence among the parents in generating promising hybrids
required by plant breeders. The purpose of this study was to determine the relative importance of heterosis, combining
abilities, regression and correlation estimates in order to develop hybrid cultivars in maize. The 28 F1 hybrids obtained by
partial diallel cross of 8 inbreds in a randomized complete block design were evaluated at the Lower Niger River Basin
Authority, Oke-Oyi, Nigeria in three years. General (GCA) and specific combining abilities (SCA) produced significant (P
< 0.01) effects for all the characters, while non-additive genetic effects were predominant. The levels of heterosis for grain
yield varied widely among crosses, ranging from -16.83 to 9.76%. Positive and significant genotypic and phenotypic
correlations among grain yield and some related characters (days to anthesis and silking; plant and ear heights; number of
ears plant-1 and 1000 seed weight) showed that each character could be used indirectly to selection of grain yield. These
results also indicated that SCA was more effective than heterosis for describing hybrid performance. The regression of
actual hybrid characters on the expected hybrid characters, based on parental GCA values, was highly significant.
Regression analysis also showed that all the agronomic characters jointly contributed 19.4% to grain yield of maize. The
inbreds (Pop 66 SR and 2000 EV DT-Y STRC4) and crosses (Pop 66 SR x, 2000 EV DT-Y STRC4, Pop 66 SR x KU1409
and 9006 x KU1409) featured prominently with respect to better GCA ร Year and SCA ร Year effects with high heterotic
values for maize grain yield and associated characters. These inbreds could serve as donors to obtain early and short
statured hybrids with higher yield, while the crosses may be exploited and adapted to the Nigerian Savannas. This study
also affirmed that genotypic and phenotypic correlation coefficients as well as combining abilities, heterosis and regression
analyses were found to be suitable models for yield improvement in maize breeding.
Correlation Coefficients Between Kernel Yield And Other Characters Of Groundn...IJRES Journal
ย
Field Trial was conducted in 1999 and 2000 at Samaru in the northern Guinea Savanna zone of Nigeria to assess the performance of 36 groundnut (Arachis hypogaea L) genotypes to Alectra vogelii (Benth). The trial was undertaken in a field that was naturally infested with Alectra. It was laid out in a randomized complete block design (RCBD) with three replications. The combined data of the two years showed that kernel yield exhibited significantly positive correlation with crop vigour at 9 weeks after sowing (WAS). Crop vigour 12 WAS, Alectra shoots population 9 WAS, Alectra shoots population 12 WAS, number of mature pods, shelling percentage, haulm yield and 100 โ kernel weight (r = 0.168*, 0.197**, 0.227**, 0.253**, 0.695**, 0.332**, 0.399** and 0.537** respectively). Plant vigour 12 WAS related strongly positive to number of mature pods and shelling percentage (r = 0.199**m 0.150* respectively). Also kernel weight correlated significantly positive with Alectra shoots population at 12WAS, shelling percentage and haulm yield (r = 0.351**, 0.254**, 0.567** respectively).
Multivariate relationships influencing crop yields during the transition to o...Myers Shaiyen
ย
This study examined the effects of tillage intensity and initial cover crops on crop yields and ecosystem functions during the transition to organic agriculture. A three-year crop rotation of cover crop (year 1), soybeans (year 2), and corn (year 3) was used. Tillage treatments were full tillage via moldboard plowing and reduced tillage via chisel plowing. Cover crop treatments were annual rye/hairy vetch or perennial timothy/red clover. Structural equation modeling was used to analyze how management practices directly and indirectly influenced crop yields by affecting soil quality, weed pressure, and predatory arthropod activity. Results showed that tillage intensity had both direct and indirect effects on corn
Cassava (mannihot esculenta cranz) varieties and harvesting stages influenced...Alexander Decker
ย
This study investigated the effects of harvesting stages on yield and yield components of 10 cassava genotypes in Ethiopia over two growing seasons. The highest fresh root yield of 23.06 t/ha was obtained after 18 months of planting. Yield and components such as root weight and number of branches differed significantly across stages for all varieties. Harvesting at 18 months provided desirable yields while 15 months was suitable for vegetative propagation material. Correlations showed that plant height, branches, root length and dry weight positively influenced fresh root yield. Therefore, 18 months after planting is recommended for fresh root harvesting under these conditions.
Field experiments were conducted at the University of Ilorin Teaching and Research Farm in 2005 and
2006 cropping seasons with the objective to evaluate the combining ability for maize grain yield and
other agronomic characters in 10 open pollinated maize varieties, which have been selected for high
yield and stress tolerance. General combining ability (gca) and year (y) effects were significant for all
the parameters except plant height, while specific combining ability (sca) and gca x year effects were
significant only for grain yield. However, Tze Comp4 Dmr Srbc2, Tze Comp4 C2 and Acr 94 Tze Comp5
which are good general combiners for maize grain yield, also showed positive significant gca x year
effects for flowering traits. Significant sca x year interaction effects were recorded for maize grain yield
and days to flowering, with Hei 97 Tze Comp3 C4 combining very well with 3 parents (Acr 90 Pool 16-Dt,
Tze Comp4-Dmr Srbc2 and Tze Comp4 C2). These parents and their hybrids probably have genes that
can be introgressed into other promising lines in developing early maturing and high yielding varieties
for cultivation in the Nigeria savannas.
Isolation Of Salmonella Gallinarum From Poultry Droppings In Jos Metropolis, ...IOSR Journals
ย
The study evaluated the effects of five different rates of poultry manure (0, 5, 10, 15, and 20 tons/hectare) on the growth and yield of watermelon over two growing seasons. Plants that received the highest rate of poultry manure (20 tons/hectare) had significantly greater vine length, number of leaves per plant, number of branches per plant, and fruit weight than plants that received lower rates or no manure. Based on the results, the study recommended that farmers in the area apply 20 tons/hectare of poultry manure to increase watermelon growth and yield.
This document discusses a study that used mixed structural covariance analysis, path analysis, and crop modeling to evaluate variation in yield components and potential yield between high-latitude and mid-European spring wheat genotypes currently grown in Finland. The study aimed to identify optimal ideotypes for each region and assess their adaptation under future climate conditions. Key findings include:
1) Modern genotypes have significantly higher yield potential than older varieties, with mid-European varieties exceeding 5 tons per hectare even under non-optimal conditions.
2) Grains per ear, harvest index, and kernel weight were the most important factors determining yield potential based on path analysis.
3) Crop modeling suggests mid-European ideotypes could achieve over 5.1 tons per
Journal of The Earth Science and Climate Change is a peer reviewed academic journal that cater to the needs of Earth Scientists, farmers, extensive agents, researchers and students. This Open access journal publishes high quality articles following rigorous and standard review procedure.
11.genotype x environment interaction analysis of tef grown in southern ethio...Alexander Decker
ย
This document summarizes a study on genotype x environment interaction of tef varieties grown in southern Ethiopia. Twenty-two tef genotypes were evaluated across four locations over two years. Significant differences were found among genotypes and locations, and for the genotype x environment interaction. Analysis of variance and AMMI modeling revealed that the variety DZ-Cr-255 was the most stable and high-yielding across locations. The locations of Areka and Hossana showed similar interaction patterns and may represent good testing environments. The study provides information to guide tef breeding efforts in the region.
Association mapping identifies loci for canopy coverage in diverse soybean ge...Avjinder (Avi) Kaler
ย
Rapid establishment of canopy coverage decreases
soil evaporation relative to transpiration improves
water use efficiency and light interception, and increases
soybean competitiveness against weeds.
Genotype by environment interaction and stability of extra-early maize hybrid...IJEAB
ย
Maize (Zea mays L.) is the most important cereal crop produced in Ghana. However the change in environmental conditions, the expansion of maize to new agro-ecologies coupled with inadequate maize varieties available for the different environments affects yield improvement programmes in Ghana. Hence, the study is to investigate the influence of genotype by environment interaction on the maize hybrids and to identify stable and high yielding hybrids with superior agronomic for famers use in the country. The objectives of the study was to investigate the influence of genotype by environment interaction on the maize hybrids and to identify stable and high yielding hybrids with superior agronomic performance for famers use in Ghana. Thus, fifteen extra-early maize hybrids and three locally released checks were evaluated in a randomized complete block design with three replications in two locations in Ghana. The experiment was carried out at KNUST and Akomadan which represent the forest and forest transition zones of Ghana. Nine of the hybrids out of the fifteen hybrids evaluated produce above the average yield and the effect of genotype, location and genotype by location interaction was significant for grain yield. The GGE biplot used in this study revealed that TZEEI-1 x TZEEI-21, TZEEI-6 x TZEEI-21, TZEEI-15 x TZEEI-1 and TZEEI-29 x TZEEI-21 were high yielding and stable hybrids because they were closer to the ideal. The GGE biplot also identified Akomadan as the most ideal testing environment for these hybrids under irrigation.
Genotype by Environment Interaction of Full-sib Families of Maize Endosperms ...Premier Publishers
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The present study was conducted at the Teaching and Research Farms, Federal University of Agriculture, Makurdi and Research Farm, College of Agriculture, Lafia to evaluate the presence of genotype by environment interactions in a population of 300 FS families of three maize endosperms to ascertain their agronomic performance, yield and stability across environments. The experiment was laid out in a 10 ร 10 balanced lattice square design with three replications. Results from the GGE Biplot for mean grain yield performance showed the entry P93 (Popcorn) obtained the highest yield at Lafia while F5 (Field Corn) had the highest yield and thus the winning family for Makurdi. The entries S72, P98, P90, S20, P31, and P54 were the most stable with an above average performance and thus recommended. The significant Location by Entries interaction effects for grain yield explains that a promising genotype selected in one of these locations will not be suitable for production in the other locations in the same agro-ecological zone, however, P93 (Popcorn) and F5 (Field corn) recorded the highest yield for Lafia and Makurdi respectively. The identified stable or location specific families should be crossed in all possible combinations to complete Cycle 1 of the FS families in a recurrent selection programme.
Development of drought tolerant maize cultivars is prerequisite to achieving stable grain yield in
droughtโprone ecologies of Nigeriaโs Guinea savanna. However, success has been limited mainly due
to lack of maize genotypes that show clear differences in response to well defined moisture deficit
condition. Two sets of drought tolerant (DT) maize germplasm were evaluated under screenhouse and
field conditions between 1999 and 2002. In the screenhouse study, performances of the genotypes
were compared under well-watered condition and moisture deficit imposed at different growth stages.
Under field conditions, the first set comprising 11 accessions along with a check were evaluated for 4
growing seasons while the second set which comprised 3 DT varieties were evaluated along with 2
check varieties using monthly plantings between April and August of 2001 and 2002, respectively. In
the first set, post anthesis moisture deficit significantly reduced grain yield by 25 to 73.5% in the open
pollinated varieties (OPVs) and by 20 to 64% in the hybrids. Grain yield under field conditions ranged
from 2.48 to 3.49, 2.82 to 3.73 and 3.58 to 4.76 tons/ha-1 for 1999, 2000 and 2001 full growing seasons,
respectively, and 2.03 to 2.50 tons/ha-1 for 2000 late growing season. In the second set, pre and post
anthesis moisture deficits reduced grain yield by 77.6 and 95.8%, respectively, of well watered
condition while in the field, grain yields in the genotypes were highest for plantings made in April and
July (1.90 - 2.5 t/ha), lowest for August (0.7 -1.8 t/ha) when moisture deficit coincided with
reproductive phase. Yield stability exhibited under moisture deficit and on the field by 8522-2, Oba
super 2 and AK9943-DMRSR in the first set as well as DT-SR-Y C0 and DT-SR-W C0 in the second set,
indicates their suitability either as cultivars per se or as potential source of DT alleles for
development of DT maize varieties for Nigeriaโs savanna ecologies.
This document describes a study that used association mapping to identify genomic regions associated with canopy temperature (CT) in soybeans under drought conditions. The study evaluated 345 soybean accessions in three environments, measuring CT using aerial infrared imaging. 52 single nucleotide polymorphisms (SNPs) were significantly associated with normalized CT (nCT), tagging 34 genomic regions. Several of the identified regions contained genes related to drought tolerance functions like transpiration, water acquisition, and response to abscisic acid. Fifteen SNPs associated with nCT were also associated with canopy wilting. The study aims to identify genotypes and alleles that can be used in breeding programs to improve soybean drought tolerance.
Effect of storage methods of cassava planting materials on establishment and ...Innspub Net
ย
Cassava (Manihot esculenta Cruntz.) establishment depends on quality of planting materials. The experiment was done to determine the effects storage and variety on crop establishment and early growth vigour. Karembo and KME 4 varieties were stored in clamp under double shade (CUDS), horizontal under shade (HUS), vertical under shade (VUS) and horizontal under open ground (HOUG) as control for 16 weeks. Planting materials was sampled from each storage methods after every 4 weeks and taken to field to evaluate their sprouting ability, number of primary shoots formation, number of leaves, rate of leaf formation and early growth vigour. Data were subjected to ANOVA and means separated by LSD. Sprouting percentage at Kabete was 54.73 % while in Kiboko had 37.78 %. The results showed that Kabete had 1.60 number of primary shoots per plant compared to 1.04 of Kiboko. The results showed KME4 had higher sprouting than Karembo in both sites. This can be due to genetic difference among varieties. The rate of leaf formation at Kiboko was higher as compared to Kabete it could be contribute difference in temperature between locations. Thus, optimum temperature and relative humidity should be factored in cassava cuttings storage to avoid increased death of stored cuttings. In case of storage cassava cuttings, should be stored in clamp under double shade methods under low temperature and moderate RH.
Seasonal growth patterns of Arundo donax L. in the United States | IJAAR @sli...Innspub Net
ย
Giant reed (Arundo donax L.) has been extensively evaluated as a dedicated energy crop for biomass and biofuel production in southern Europe and the United States, with very favorable results. Current agronomic and biologic research on giant reed focuses on management practices, development of new cultivars, and determining differences among existing cultivars. Even though detailed information on the growth patterns of giant reed would assist in development of improved management practices, this information is not available in the United States. Therefore, the objective of this 2-year field study was to describe the seasonal growth patterns of giant reed in Alabama, United States. Changes in both plant height and biomass yield of giant reed with time were well described by a Gompertz function. The fastest growing period occurred at approximately 66 d after initiation of regrowth (mid-May), when the absolute maximum growth rate was of 0.045 m d-1 and 0.516mg ha-1 d-1. After mid-May, the rate of growth decreased until maturation at approximately 200 d after initiation of regrowth (mid- to late September). The observed maximum average plant height and biomass yield were 5.28 m and 48.56mg ha-1, respectively. Yield decreased following maturation up to 278 d after initiation (early to mid-December) of growth in spring, partly as a result of leaf loss, and was relatively stable thereafter.
Field experiments were conducted to investigate the variations in sixteen maize genotypes in relation to drought tolerance. The experimental set up was subjected to drought stress after five weeks of planting for three weeks before data on morphological and yield characters of maize genotypes were obtained for three cropping years. Plant height and grain yield of Bodija yellow maize were the highest overall. There was a significant difference among genotypes for drought stress resistance and Bodija yellow maize showed the most tolerance, while TZBR Comp 1 โ C1 S2 510 genotype was the least. First principal component axis (Prin 1) had the highest contribution to the variation of the morphological, yield and drought tolerance traits. Prin 1 was highly related to the morphological and yield characters more than to the drought resistance. Plant height was negatively and strongly correlated (p<0.01) with stem height, number of leaves, stem girth, leaf length, leaf width and week after planting, but negatively correlated with the drought resistance. Therefore, Bodija yellow maize should be considered as parent material in breeding for the development of drought tolerant traits in maize.
Seasonal Dynamics of Arbuscular Mycorrhizal Fungi, Glomalin and Soil Properti...ijtsrd
ย
To understand the ecological significance of arbuscular mycorrhizal fungal (AMF) associations in agroecosysytem, the host specific and seasonal dynamics of AMF and glomalin-related soil protein (GRSP) was investigated in agricultural fields of Nanded, Maharashtra State. Soil samples were collected from the rhizosphere of eight crop plants (Glycine max (L.) Merr., Saccharum officinarum L., Zea mays L., Cajanas cajan (L.) Millsp., Gossypium arboreum L., Triticum aestivum L., Sorghum vulgare Pers. and Cicer arietinum L.) in winter, summer and monsoon seasons respectively. Arbuscular mycorrhizal root infection and spore density of AMF peaked in monsoon and winter.The mean contents of total glomalin related soil proteins (T-GRSP) reached maximal values in summer. Spore density was highest in Zea mays L. Easily extractable glomalin related (EE-GRSP) and T-GRSP fractions were the highest in the rhizosphere of Cicer arietinum L. and Sorghum vulgare Pers. AMF root colonization and spore density was negatively correlated with K (P < 0.05; P < 0.01). T-GRSP fraction was positively correlated with edaphic factors (rhizosphere temperature, K and Fe content of soil) and negatively correlated with soil moisture (P < 0.01), AMF root colonization (P < 0.05) and spore density (P http://www.ijtsrd.com/biological-science/ecology/15727/seasonal-dynamics-of-arbuscular-mycorrhizal-fungi-glomalin-and-soil-properties-in-agroecosystems-of-nanded-district/ujwala-sheshrao-deepake
Genotype x environment interaction analysis of tef grown in southern ethiopia...Alexander Decker
ย
This document summarizes a study that evaluated 22 tef genotypes for grain yield performance across four locations in southern Ethiopia. Significant differences were found among genotypes and locations, and for the genotype x environment interaction. Analysis of variance and AMMI modeling were used to analyze the data. The study found that genotype DZ-Cr-255 was the most stable and high-yielding variety across locations. Areka and Hossana locations showed similar patterns of interaction and had higher average yields, indicating they may be better test environments. The first principal component axis from the AMMI analysis captured 48.7% of the genotype x environment interaction variance.
GGEBiplot analysis of genotype ร environment interaction in Agropyron interme...Innspub Net
ย
In order to identify genotypes of Agropyron intermedium with high forage yield and stability an experiment was carried out in the Research station of Kermanshah Iran.The 11 accessions were sown in a randomized complete block design with three replications under rainfed and irrigated conditions during 2013-21-014 cropping deasons. Combined analysis of variance indicated high significant differences for location, genotype and G ร E interaction (GEI) at 1% level of probability. Mean comparisons over environments introduced G4, G3 and G5 with maximum forage yield over rainfed and irrigated conditions. Minimum forage yield was attributed to genotype G1. GGEbiplot analysis exhibited that the first two principal components (PCA) resulted from GEI and genotype effect justified 99.37% of total variance in the data set. The four environments under investigation fell into two apparent groups: irrigated and rainfed. The presence of close associations among irrigated (E1 and E3) and rainfed (E2 and E4) conditions suggests that the same information about the genotypes could be obtained from fewer test environments, and hence the potential to reduce testing cost.The which-won-where pattern of GGEbiplot introduced genotypes G3 and G4 as stable with high forage yield for rainfed condition, while G5 was stable with high yield for irrigated condition. According to the comparison of the genotypes with the Ideal genotype accessions G4, G3 and G9 were more favorable than all the other genotypes. Get more articles at: http://www.innspub.net/volume-6-number-4-april-2015-jbes/
Genetic control and heterosis depend directly on genetic divergence among the parents in generating promising hybrids
required by plant breeders. The purpose of this study was to determine the relative importance of heterosis, combining
abilities, regression and correlation estimates in order to develop hybrid cultivars in maize. The 28 F1 hybrids obtained by
partial diallel cross of 8 inbreds in a randomized complete block design were evaluated at the Lower Niger River Basin
Authority, Oke-Oyi, Nigeria in three years. General (GCA) and specific combining abilities (SCA) produced significant (P
< 0.01) effects for all the characters, while non-additive genetic effects were predominant. The levels of heterosis for grain
yield varied widely among crosses, ranging from -16.83 to 9.76%. Positive and significant genotypic and phenotypic
correlations among grain yield and some related characters (days to anthesis and silking; plant and ear heights; number of
ears plant-1 and 1000 seed weight) showed that each character could be used indirectly to selection of grain yield. These
results also indicated that SCA was more effective than heterosis for describing hybrid performance. The regression of
actual hybrid characters on the expected hybrid characters, based on parental GCA values, was highly significant.
Regression analysis also showed that all the agronomic characters jointly contributed 19.4% to grain yield of maize. The
inbreds (Pop 66 SR and 2000 EV DT-Y STRC4) and crosses (Pop 66 SR x, 2000 EV DT-Y STRC4, Pop 66 SR x KU1409
and 9006 x KU1409) featured prominently with respect to better GCA ร Year and SCA ร Year effects with high heterotic
values for maize grain yield and associated characters. These inbreds could serve as donors to obtain early and short
statured hybrids with higher yield, while the crosses may be exploited and adapted to the Nigerian Savannas. This study
also affirmed that genotypic and phenotypic correlation coefficients as well as combining abilities, heterosis and regression
analyses were found to be suitable models for yield improvement in maize breeding.
Correlation Coefficients Between Kernel Yield And Other Characters Of Groundn...IJRES Journal
ย
Field Trial was conducted in 1999 and 2000 at Samaru in the northern Guinea Savanna zone of Nigeria to assess the performance of 36 groundnut (Arachis hypogaea L) genotypes to Alectra vogelii (Benth). The trial was undertaken in a field that was naturally infested with Alectra. It was laid out in a randomized complete block design (RCBD) with three replications. The combined data of the two years showed that kernel yield exhibited significantly positive correlation with crop vigour at 9 weeks after sowing (WAS). Crop vigour 12 WAS, Alectra shoots population 9 WAS, Alectra shoots population 12 WAS, number of mature pods, shelling percentage, haulm yield and 100 โ kernel weight (r = 0.168*, 0.197**, 0.227**, 0.253**, 0.695**, 0.332**, 0.399** and 0.537** respectively). Plant vigour 12 WAS related strongly positive to number of mature pods and shelling percentage (r = 0.199**m 0.150* respectively). Also kernel weight correlated significantly positive with Alectra shoots population at 12WAS, shelling percentage and haulm yield (r = 0.351**, 0.254**, 0.567** respectively).
Multivariate relationships influencing crop yields during the transition to o...Myers Shaiyen
ย
This study examined the effects of tillage intensity and initial cover crops on crop yields and ecosystem functions during the transition to organic agriculture. A three-year crop rotation of cover crop (year 1), soybeans (year 2), and corn (year 3) was used. Tillage treatments were full tillage via moldboard plowing and reduced tillage via chisel plowing. Cover crop treatments were annual rye/hairy vetch or perennial timothy/red clover. Structural equation modeling was used to analyze how management practices directly and indirectly influenced crop yields by affecting soil quality, weed pressure, and predatory arthropod activity. Results showed that tillage intensity had both direct and indirect effects on corn
Multivariate relationships influencing crop yields during the transition to o...
ย
Similar to Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Cassava (mannihot esculenta cranz) varieties and harvesting stages influenced...Alexander Decker
ย
This study investigated the effects of harvesting stages on yield and yield components of 10 cassava genotypes in Ethiopia over two growing seasons. The highest fresh root yield of 23.06 t/ha was obtained after 18 months of planting. Yield and components such as root weight and number of branches differed significantly across stages for all varieties. Harvesting at 18 months provided desirable yields while 15 months was suitable for vegetative propagation material. Correlations showed that plant height, branches, root length and dry weight positively influenced fresh root yield. Therefore, 18 months after planting is recommended for fresh root harvesting under these conditions.
Field experiments were conducted at the University of Ilorin Teaching and Research Farm in 2005 and
2006 cropping seasons with the objective to evaluate the combining ability for maize grain yield and
other agronomic characters in 10 open pollinated maize varieties, which have been selected for high
yield and stress tolerance. General combining ability (gca) and year (y) effects were significant for all
the parameters except plant height, while specific combining ability (sca) and gca x year effects were
significant only for grain yield. However, Tze Comp4 Dmr Srbc2, Tze Comp4 C2 and Acr 94 Tze Comp5
which are good general combiners for maize grain yield, also showed positive significant gca x year
effects for flowering traits. Significant sca x year interaction effects were recorded for maize grain yield
and days to flowering, with Hei 97 Tze Comp3 C4 combining very well with 3 parents (Acr 90 Pool 16-Dt,
Tze Comp4-Dmr Srbc2 and Tze Comp4 C2). These parents and their hybrids probably have genes that
can be introgressed into other promising lines in developing early maturing and high yielding varieties
for cultivation in the Nigeria savannas.
Isolation Of Salmonella Gallinarum From Poultry Droppings In Jos Metropolis, ...IOSR Journals
ย
The study evaluated the effects of five different rates of poultry manure (0, 5, 10, 15, and 20 tons/hectare) on the growth and yield of watermelon over two growing seasons. Plants that received the highest rate of poultry manure (20 tons/hectare) had significantly greater vine length, number of leaves per plant, number of branches per plant, and fruit weight than plants that received lower rates or no manure. Based on the results, the study recommended that farmers in the area apply 20 tons/hectare of poultry manure to increase watermelon growth and yield.
Development of drought-tolerant maize varieties with high and stable yields is very imperative as being affordable alternative to
many smallholder farmers. Drought-tolerant maize varieties belonging to two maturity groups (10 early and 10 late/intermediate) were evaluated
for yield and other related characters in the southern guinea savannah (SGS) of Nigeria for two years. Days to flowering were higher in
the second year than the first year. Consistent number of days (3 days) was recorded for anthesis-silking interval in both years. Plant and
ear heights are greater in 2008 than 2007. However, plant and ear aspects were fair in overall phenotypic appeal and grain yield was not
significantly difference in both years. Maize grain yield in late/intermediate varieties is significantly higher than the early with a difference of
one tonne. High grain yield recorded in two varieties each among the early (AC 90 POOL 16 DT STR and TZE-Y DT STR C4) and late/
intermediate (DT-SR-WC0 F2, SUWAN-1-SR-SYN) varieties was approximately 4.6 t/ha. These genotypes could be used either as cultivar
per se to escape the prolonged moisture stress during the later part of the cropping season or introgressed with favourable cultivars for high
yield adaptable to drought-prone areas in SGS ecologies.
Genetic Variability for Grain Yield, Flowering and Ear Traits in Early and La...Premier Publishers
ย
The document reports on a study that evaluated genetic variability for yield and yield-related traits in early and late sown full-sib families of a local sweet corn population in Makurdi, Nigeria. Families showed significant differences for all traits measured, indicating genetic variability. Genotypic and phenotypic coefficients of variation were higher for anthesis-silking interval compared to days to flowering, but similar for ear traits. Heritability was moderate for anthesis-silking interval and high for days to flowering. Higher heritability and genetic advance were observed for most traits in late sowing, suggesting faster progress from selection during this period. Full-sib recurrent selection via ear traits was recommended to improve the population for the sav
Growth and yield of 12 accessions of Pawpaw (Carica papaya L.) as influenced ...Innspub Net
ย
Pawpaw (Carica papaya L.) has gained important commercial status in Nigeria due to its nutritional, medicinal and health benefits. In recent times, there is a growing preference for pure organic food due to the envisaged health and environmental benefits. Thus, a study was carried out on 12 selected accessions of pawpaw evaluated under three poultry manure (PM) application rates at the Department of Crop Science, University of Nigeria, Nsukka. The field experiment was a split plot in randomized complete block design of three replications. The main plot treatment was three PM application rates (0, 5 and 10 t ha-1) and the sub-plot treatment was 12 accessions of pawpaw. Accession Ijm-Cl-Ro significantly (p<0.05) produced the tallest plants (71.7, 87.3, 108.3, 127.4 and 150.0cm) at 3, 6, 9, 12 and 15 months after transplanting (MAT), respectively. It had the greatest number of fruits (9.3) at 11 months after the onset of fruit formation, maximum fruit weight (7.15kg) and the highest fruit yield (23.83 t ha-1). Increasing PM rate increased growth traits of the pawpaw plants. Interaction of manure rate ร accession on most of the growth attributes varied greatly, but showed no significant difference on yield traits. The accession Ijm-Cl-Ro with the application of 10 t ha-1 of PM which produced the best growth and highest fruit yield is recommended for improved productivity of pawpaw. The control plot produced no fruit throughout the study period, suggesting that manure application is crucial for sustained yield of pawpaw in the study area.
Variation in grain yield and other agronomic traits in soybean Alexander Decker
ย
This document summarizes the results of an experiment evaluating 25 soybean varieties in Makurdi, Nigeria with the goal of identifying high-yielding varieties to replace the popular variety TGX 1448-2E. Significant differences were found between varieties for traits like days to flowering, maturity, plant height, pod number, yield, and more. Seven varieties - TGX1990-98F, TGX1991-10F, TGX1990-86F, UG5, TGX1485-1D, TGX1990-48F and TGX1990-80F - yielded higher than TGX 1448-2E and were identified as possible replacements, requiring further testing across more locations.
Grain Yield Stability in Three-way Cross Hybrid Maize Varieties using AMMI an...Premier Publishers
ย
A study to evaluate three-way cross hybrid maize varieties for wide adaptability and stability was conducted in eight environments in Sierra Leone using AMMI and GGE biplot analysis. There were significant genotype and environment main effects, and genotype x environment interactions (GEI) effects. Differences due to environments accounted for 70.1% of the total treatments sum of squares while genotypes and genotype x environment interaction accounted for 9.9% and 20.0%, respectively. The first four interaction principal component axes (IPCA) were also highly significant and accounted for 38.7%, 25.2%, 14.3% and 8.6%, respectively of the total genotype x environment interaction variation. The polygon view of the GGE biplot revealed that hybrid G14 produced the highest grain yield in environments E1, E5 and E7 whereas G24 was adaptive in environments E6, E8, E3, E4 and E2. Hybrids G24, G9, G17 and G6 also produced high grain yields and were relatively stable. Both AMMI and GGE biplot effectively partitioned treatments sum of squares and were more appropriate in explaining genotype x environment interaction. The models also identified G24 as the most desirable hybrid in terms of high grain yield and stability across environments. Therefore, this hybrid is recommended for commercial release.
Genotype by Environment Interaction on Yield Components and Stability Analysi...Premier Publishers
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Newly developed varieties can only contribute to increased productivity if high producing varieties are released in production niches they are adapted to. In order to enhance adoption of new improved cassava varieties in western Kenya, a study was conducted to evaluate the effects of genotype by environment interaction (GEI) on agronomic and farmer preferred traits of cassava and to asses yield stability of 16 cassava genotypes. The study was conducted in randomized complete block design with three replications across five different environments of western Kenya. AMMI analysis of variance identified highly significant (P= 0.001) GEI effects for plant height, height at first branching, and fresh root yield. Generally, GEI effects accounted for 14.98%, 24.64% and 28.3% variability in PH, HB, and FRY respectively. GGE biplot analysis shows that MM06/0138, MM96/9308, MM97/0293, MM98/3567, MM06/0074, MM96/4271 were high yielding and stable genotypes. AMMI stability value revealed that genotype MM06/0143 combined high stability for plant height, height at first branching, number of storage roots and fresh root yield. Genotypes MM06/0138, MM98/3567, MM96/9308, MM97/0293, and MM06/0074 outperformed the check in storage roots yield exhibited high yields in farmer preferred traits and were classified as stable genotypes. Therefore, recommended for release to farmers.
Nodulation, Growth and Yield Response of Five Cowpea (Vigna unguiculata L. Wa...Premier Publishers
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The experiment was carried out in the screen house of the Department of Crop, Soil & Pest Management, Federal University of Technology, Akure, Nigeria. The experimental layout was a 5 x 3 x 2 factorial combination with 3 replications given a total of 90 treatments. Seeds of five cowpea varieties namely: IT98K-205-8, Ife Brown, Oloyin Brown, IT98K-573-2-1 and IT96D-610 were sown in Plastic buckets of 7-liter capacity and were perforated at the bottom to allow for drainage and filled with top soil. Watering regimes of (500ml, 700ml and 900ml) were imposed and water was applied twice a week while cowpea plants were inoculated with 5g each of Rhizobia strain (Mesorhizobia loti) at seedling stage. Control set was maintained without inoculation. The effect of watering regimes on legume species was significant on nodulation, growth and yield characters of cowpea varieties evaluated. The results revealed marked varietal differences in plant growth, nodulation, yield and yield components. IT98K-573-2-1 and Oloyin Brown generally expressed superior performance in most measured parameters. Mesorhizobia inoculation significantly (pโค0.05) increased plant growth, nodulation, yield and yield components of cowpea. The interaction effect of variety, Mesorhizobia loti and watering regimes caused significant variations in the number of nodules, leaf area, number of seeds/pod and seed yield. The nitrogen and crude protein content in the leaf differed among the cowpea varieties evaluated. Application of mesorhizobium strain significantly increased seed yield of cowpea and caused substantial increase in nodulation and this subsequently affected the Nitrogen fixation potential of cowpea under varying soil moisture regimes.
Combining Ability and Heterosis for Grain Yield and Other Agronomic Traits in...Premier Publishers
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A varietal diallel of eight parents (3 sweet corn, 1 popcorn and 4 field corn) was evaluated at the Teaching and Research Farms of College of Agriculture, Lafia and Federal University of Agriculture, Makurdi respectively, to estimate combining ability, heterosis and gene action. The experiments were laid out as 8x8 ฮฑ-lattice design with three replications in both locations during the 2018 rain-fed cropping season. Data was collected on emergence count, chlorophyll content, days to tasselling, days to silking, plant height, ear height and grain yield. A significant difference (pโค 0.05 and pโค 0.01) in the General Combining Ability (GCA), Specific Combining Ability (SCA) and Reciprocals was observed, with apparent additivity for all the traits. Both negative and positive GCA, SCA and Reciprocal effects and heterosis were observed for all the traits studied. Recurrent selection in TZY-sh2-Y, MAW-sh2-W, SAMMAZ 39, TZEE 2009 and MAY-PC-Y for earliness, dwarfism, vigour and yield was recommended for further breeding towards the improvement of these genotypes in the Southern Guinea Savanna ecology of Nigeria.
Response of late season maize soybean intercropping to nitrogen in the humid ...Alexander Decker
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This document summarizes a study on the response of late season maize/soybean intercropping to nitrogen fertilizer in southern Nigeria. The study investigated different nitrogen rates (0-100 kg/ha) and crop arrangements (sole and mixed cropping) on maize and soybean yield. The results showed that nitrogen fertilization increased yields for both crops in both sole and mixed systems. Applying 100 kg/ha nitrogen to maize increased various yield components by 15-153% compared to no nitrogen. For soybean, 100 kg/ha nitrogen increased yield components by 14-120% over no nitrogen. Optimum soybean yield was obtained at 50 kg/ha nitrogen. Intercropping maize and soy
Agro physiological characteristics of qpm genotypes as influenced by irrigati...Alexander Decker
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This study evaluated the agrophysiological characteristics of three Quality Protein Maize (QPM) genotypes (TZE-W Pop x 1368, EV DT-W 99 STR, and DMR-ESRW) under different irrigation schedules (40, 60, and 80 centibars) and plant populations (33,333, 44,444, 55,555, and 66,666 plants/ha) in a semi-arid region of Nigeria over three growing seasons. The results showed that genotype EV-DT W99 STR had significantly higher relative growth rate, crop growth rate, net assimilation rate, and total dry matter compared to the other genotypes. Increasing plant population significantly decreased leaf area index and net assimilation rate
Knowledge of the magnitude of genetic variability, heritability and genetic gains in selection of desirable characters could assist the plant breeder in ascertaining criteria to be used for the breeding programmes. Ten open pollinated maize varieties were evaluated at the Teaching and Research farm, University of Ilorin, Nigeria, during 2005 and 2006 cropping seasons to estimate genetic variability, heritability and genetic advance of grain yield and its component characters. The effect of genotype and genotype by year interaction were significant for ear weight and grain yield, while the effect of year was highly significant (P< 0.01) for all the characters. High magnitude of phenotypic and genotypic coefficient of variations as well as high heritability along with high genetic advance recorded for grain yield, number of grains ear-1, ear weight, plant and ear heights provides evidence that these parameters were under the control of additive gene effects and effective selection could be possible for improvement for these characters. Tze Comp3 C2, Acr 94 Tze Comp5, Tze Comp 4-Dmr Srbc2 and Acr 90 Pool 16-Dt were identified as outstanding genotypes for maize grain yield and should be tested at multilocation for their yield performance.
Farmersโ perception of climate change in ikwuano local government area of abi...Alexander Decker
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This document summarizes a study on farmers' perceptions of climate change in Ikwuano Local Government Area of Nigeria. The study found that farmers are aware that the climate is changing, with increases in temperature, changes in rainfall patterns, and decreases in agricultural yields. The farmers perceived the main causes of climate change to be deforestation, industrialization, overpopulation, pollution, and overexploitation of resources. However, financial constraints, lack of climate information, and insufficient extension support limited farmers' ability to adopt measures to mitigate the effects of climate change on their agricultural activities.
Seed managementโs influences on nodulation and yield of improved variety of s...Agriculture Journal IJOEAR
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Abstractโ A pot study was carried out on an improved soybean variety (TGX 1448-2E) to assess the effects of seed management on its nodulation and yield. The experiment was in factorial combinations with six replicates at the teaching and research farm of University of Abuja. The factors were 2 soils, 2 levels of phosphorus fertilizer (-P and + P), and 2 seed sources (farmerโs and researcherโs managed seeds). P was applied as triple superphosphate at 30 kg P ha-1. Destructive sampling was done at 8 weeks after planting to record growth parameters and nodulation. At maturity, the number and weight of pods, weight of 50 seeds and total seed yield were recorded. The results showed that generally researchersโ managed seeds showed a significantly higher mean values than farmersโ managed seeds. The pod and total seed weight from researchersโ seeds were 106.26 g and 52.43 g per plant respectively against the farmersโ managed seed with pod weight of 80.23 g and total seed weight of 44.35 g per plant. P application influenced significantly the weight of nodules, pods and seeds per plant. This significant lower performance observed in farmersโ managed seeds could have resulted from factors such poor seed handling or mix up during harvesting or storage, poor quality seed selection for planting.
Phenotypic Correlation and Heritability Estimates of some Quantitative Charac...Premier Publishers
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This study evaluated 16 advanced rice varieties under different nitrogen fertilizer levels to determine phenotypic correlations and heritability estimates of quantitative traits. Field experiments were conducted in Malaysia over two seasons. Data was collected on plant height, tillers per hill, panicles per hill, filled grains per panicle, and unfilled grains per panicle. Significant variation was observed among genotypes and in response to nitrogen levels for most traits. High phenotypic and genotypic coefficient of variation, heritability, genetic advance, and positive correlations between yield components indicated the influence of traits like tonnes per hectare, grain weight per plot, and kilograms per plot on yield. High heritability estimates suggested additive gene effects were more important than environmental effects
A comparative study on the response of six maize hybrids: two
hybrids each from the 1980s (8321-21 and 8425-8), 1990s (9801-11 and 9803-2)
and 2000s (0103-11 and 0103-15) to sub-optimal and optimal nitrogen fertilization
was conducted in Oke-Oyi, Nigeria. The trials were set up in a split plot with three
nitrogen levels (0, 30 and 90 kg N ha-1) as a main plot and six hybrids as sub-plots.
Significant interactions were observed between hybrid and N level for all
characters, with increasing in variation as the level of N decreased. Mean grain
yield reductions across eras were 73.8% at no-N and 32.6% at low-N, and those of
optimal-N fertilization were 34.3% and 15.7% for 1980s and 1990s genotypes
respectively. Depending on N treatment, grain yield varied from 0.67 to 4.89 t ha-1.
Kernel number was most severely reduced by N stress, but had positive and highly
significant (pโค0.01) correlation with grain yield at all N levels. Genetic gains in
grain yield were 42% (between 1980 and 2000 eras) and 9% (between 1990 and
2000 eras) under optimal-N fertilization. The two modern hybrids of 2000 era
(0103-11 and 0103-15) were outstanding for all the agronomic traits and leaf
chlorophyll concentration at all N levels. Improving traits associated with fertilizer
N response could accelerate rate of genetic gains in maize yields.
Extension services strategies in adaptation to climate change in oyo state, n...Alexander Decker
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The document discusses extension service strategies for adapting to climate change in Oyo State, Nigeria. It finds that farmers experienced impacts of climate change like drought, changes in rainfall patterns, and decreased water availability. To cope, farmers adopted strategies recommended by extension agents, including changing crops grown, conservation agriculture, and early warning systems. The roles of extension agents were seen as important for building farmers' capacity to adapt, through demonstrations and sharing innovations. However, low funding, changing policies, and lack of access to information constrained adoption of adaptation strategies. The study concludes that more public education on adaptation is needed to support extension agents' work in mitigating climate impacts.
Similar to Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria (20)
Evaluation of Agro-morphological Performances of Hybrid Varieties of Chili Pe...Premier Publishers
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In Benin, chilli pepper is a widely consumed as vegetable whose production requires the use of performant varieties. This work assessed, at Parakou and Malanville, the performance of six F1 hybrids of chilli including five imported (Laali, Laser, Nandi, Kranti, Nandita) and one local (De cayenne), in completely randomized block design at four replications and 15 plants per elementary plot. Agro-morphological data were collected and submitted to analysis of variance and factor analysis of mixed data. The results showed the effects of variety, location and their interactions were highly significant for most of the growth, earliness and yield traits. Imported hybrid varieties showed the best performances compared to the local one. Multivariate analysis revealed that 'De cayenne' was earlier, short in size, thin-stemmed, red fruits and less yielding (โ 1 t.ha-1). The imported hybrids LaaliF1 and KrantiF1 were of strong vegetative vigor, more yielding (> 6 t.ha-1) by developing larger, long and hard fruits. Other hybrids showed intermediate performances. This study highlighted the importance of imported hybrids in improving yield and preservation of chili fruits. However, stability and adaptation analyses to local conditions are necessary for their adoption.
An Empirical Approach for the Variation in Capital Market Price Changes Premier Publishers
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The chances of an investor in the stock market depends mainly on some certain decisions in respect to equilibrium prices, which is the condition of a system competing favorably and effectively. This paper considered a stochastic model which was latter transformed to non-linear ordinary differential equation where stock volatility was used as a key parameter. The analytical solution was obtained which determined the equilibrium prices. A theorem was developed and proved to show that the proposed mathematical model follows a normal distribution since it has a symmetric property. Finally, graphical results were presented and the effects of the relevant parameters were discussed.
Influence of Nitrogen and Spacing on Growth and Yield of Chia (Salvia hispani...Premier Publishers
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Chia is an emerging cash crop in Kenya and its production is inhibited by lack of agronomic management information. A field experiment was conducted in February-June and May-August 2021, to determine the influence of nitrogen and spacing on growth and yield of Chia. A randomized complete block design with a split plot arrangement was used with four nitrogen rates as the main plots (0, 40, 80, 120 kg N ha-1) and three spacing (30 cm x 15 cm (s1), 30 cm x 30 cm (s2), 50 cm x 50 cm (s3)). Application of 120 kg N ha-1 significantly increased (pโค0.05) vegetative growth and seed yield of Chia. Stem height, branches, stem diameter and leaves increased by 23-28%, 11-13%, 43-55% and 59-88% respectively. Spacing s3 significantly increased (pโค0.05) vegetative growth. An increase of 27-74%, 36-45% and 73-107% was recorded in number of leaves, stem diameter and dry weight, respectively. Chia yield per plant was significantly higher (pโค0.05) in s3. However, when expressed per unit area, s1 significantly produced higher yields. The study recommends 120 kg N ha-1 or higher nitrogen rates and a closer spacing of 15 cm x 30 cm as the best option for Chia production in Kenya.
Enhancing Social Capital During the Pandemic: A Case of the Rural Women in Bu...Premier Publishers
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The document discusses a case study of enhancing social capital among rural women in Bukidnon Province, Philippines during the COVID-19 pandemic through a livelihood project. Key findings include:
1) Technical trainings provided by the project increased the women's knowledge, allowing them to generate additional household income through vegetable gardening during the pandemic.
2) The women's social capital, as measured by groups/networks, trust, and cooperation, increased by 15.5% from 2019 to 2020 through increased participation in their association.
3) Main occupations, income sources, and ethnicity influenced the women's social capital. The project enhanced social ties that empowered the rural women economically and socially despite challenges of the pandemic.
Impact of Provision of Litigation Supports through Forensic Investigations on...Premier Publishers
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This paper presents an argument through the fraud triangle theory that the provision of litigation supports through forensic audits and investigations in relation to corporate fraud cases is adequate for effective prosecution of perpetrators as well as corporate fraud prevention. To support this argument, this study operationalized provision of litigation supports through forensic audit and investigations, data mining for trends and patterns, and fraud data collection and preparation. A sample of 500 respondents was drawn from the population of professional accountants and legal practitioners in Nigeria. Questionnaire was used as the instrument for data collection and this was mailed to the respective respondents. Resulting responses were analyzed using the OLS multiple regression techniques via the SPSS statistical software. The results reveal that the provision of litigation supports through forensic audits and investigations, fraud data mining for trends and patterns and fraud data collection and preparation for court proceedings have a positive and significant impact on corporate fraud prevention in Nigeria. This study therefore recommends that regulators should promote the provision of litigation supports through forensic audits and investigations in relation to corporate fraud cases in publicly listed firms in Nigeria, as this will help provide reports that are acceptable in court proceedings.
Improving the Efficiency of Ratio Estimators by Calibration WeightingsPremier Publishers
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It is observed that the performances of most improved ratio estimators depend on some optimality conditions that need to be satisfied to guarantee better estimator. This paper develops a new approach to ratio estimation that produces a more efficient class of ratio estimators that do not depend on any optimality conditions for optimum performance using calibration weightings. The relative performances of the proposed calibration ratio estimators are compared with a corresponding global [Generalized Regression (GREG)] estimator. Results of analysis showed that the proposed calibration ratio estimators are substantially superior to the traditional GREG-estimator with relatively small bias, mean square error, average length of confidence interval and coverage probability. In general, the proposed calibration ratio estimators are more efficient than all existing estimators considered in the study.
Urban Liveability in the Context of Sustainable Development: A Perspective fr...Premier Publishers
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Urbanization and quality of urban life are mutually related and however it varies geographically and regionally. With unprecedented growth of urban centres, challenge against urban development is more in terms of how to enhance quality of urban life and liveability. Making sense of and measuring urban liveability of urban places has become a crucial step in the context of sustainable development paradigm. Geographical regions depict variations in nature of urban development and consequently level of urban liveability. The coastal regain of West Bengal faces unusual challenges caused by increasing urbanization, uncontrolled growth, and expansion of economic activities like tourism and changing environmental quality. The present study offers a perspective on urban liveability of urban places located in coastal region comprising of Purba Medinipur and South 24 Parganas districts. The study uses the liveability standards covering four major pillars- institutional, social, economic and physical and their indicators. This leads to develop a City Liveability Index to rank urban places of the region, higher the index values better the urban liveability. The data for the purpose is collected from various secondary sources. Study finds that the eastern coastal region of the country covering state of West Bengal depicts variations in index of liveability determined by physical, economic, social and institutional indicators.
Transcript Level of Genes Involved in โRebaudioside Aโ Biosynthesis Pathway u...Premier Publishers
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Stevia rebaudiana Bertoni is a plant which has recently been used widely as a sweetener. This medicinal plant has some components such as diterpenoid glycosides called steviol glycosides [SGs]. Rebaudioside A is a diterpenoid steviol glycoside which is 300 times sweeter than table sugar. This study was done to investigate the effect of GA3 (50 mg/L) on the expression of 14 genes involved in Rebaudioside A biosynthesis pathway in Stevia rebaudiana under in vitro conditions. The expression of DXS remarkably decreased by day 3. Also, probably because of the negative feedback of GA3 on MEP-drived isoprenes, GGDS transcript level reached its lowest amount after GA3 treatment. The abundance of DXR, CMS, CMK, MCS, and CDPS transcripts showed a significant increase at various days after this treatment. A significant drop in the expression levels of KS and UGT85C2 is detected during the first day. However, expression changes of HDR and KD were not remarkable. Results revealed that the level of transcript of UGT74G1 and UGT76G1 up regulated significantly 4 and 2 times higher than control, respectively. However, more research needs to shed more light on the mechanism of GA3 on gene expression of MEP pathway.
Multivariate Analysis of Tea (Camellia sinensis (L.) O. Kuntze) Clones on Mor...Premier Publishers
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Information on genetic variability for biochemical characters is a prerequisite for improvement of tea quality. Thirteen introduced tea clones characterized with objective; assessing tea clones based on morphological characters at Melko and Gera research stations. The study was conducted during 2017/18 cropping season on experimental plots in RCBD with three replications. Data recorded on morphological traits like days from pruning to harvest, height to first branch, stem diameter, leaf serration density, leaf length, leaf width, leaf size, petiole length, leaf ratio, internode length, shoot length, number of shoot, canopy diameter, hundred shoot weight, fresh leaf yield per tree. Cluster analysis of morphological trait grouped into four clusters indicated, the existence of divergence among the tested clones. The maximum inter-cluster distance was between clusters I and IV (35.27) while the minimum inter cluster distance was observed between clusters I and II (7.8).Principal components analysis showed that the first five principal components with eigenvalues greater than one accounted 86.45% for 15 morphological traits. Generally, the study indicated presence of variability for several morphological traits. However, high morphological variation between clones is not a guarantee for a high genetic variation; therefore, molecular studies need to be considered as complementary to biochemical studies.
Causes, Consequences and Remedies of Juvenile Delinquency in the Context of S...Premier Publishers
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This research work was designed to examine nature of juvenile offences committed by juveniles, causes of juvenile delinquency, consequences of juvenile delinquency and remedies for juvenile delinquency in the context of Sub-Saharan Africa with specific reference to Eritrea. Left unchecked, juvenile delinquents on the streets engage in petty theft, take alcohol or drugs, rape women, rob people at night involve themselves in criminal gangs and threaten the public at night. To shed light on the problem of juvenile delinquency in the Sub-Saharan region data was collected through primary and secondary sources. A sample size of 70 juvenile delinquents was selected from among 112 juvenile delinquents in remand at the Asmara Juvenile Rehabilitation Center in the Eritrean capital. The study was carried out through coded self-administered questionnaires administered to a sample of 70 juvenile delinquents. The survey evidence indicates that the majority of the juvenile respondents come either from families constructed by unmarried couples or separated or divorced parents where largely the father is missing in the home or dead. The findings also indicate that children born out of wedlock, families led by single mothers, lack of fatherly role models, poor parental-child relationships and negative peer group influence as dominant causes of juvenile infractions. The implication is that broken and stressed families are highly likely to be the breeding grounds for juvenile delinquency. The survey evidence indicates that stealing, truancy or absenteeism from school, rowdy or unruly behavior at school, free-riding in public transportation, damaging the book of fellow students and beating other young persons are the most common forms of juvenile offenses. It is therefore, recommended that parents and guardians should exercise proper parental supervision and give adequate care to transmit positive societal values to children. In addition, the government, the police, prosecution and courts, non-government organizations, parents, teachers, religious leaders, education administrators and other stakeholders should develop a child justice system that strives to prevent children from entering deeper into the criminal justice process.
The Knowledge of and Attitude to and Beliefs about Causes and Treatments of M...Premier Publishers
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Stigma and discrimination associated with mental illness are a common occurrence in the Sub-Saharan region including Eritrea. Numerous studies from Sub-Saharan Africa suggest that stigma and discrimination are major problems in the community, with negative attitudes and behavior towards people with mental illness being widespread. In order to assess the whether such negative attitudes persist in the context of Eritrea this study explored the knowledge and perceptions of 90 Eritrean university students at the College of Business and Economics, the University of Asmara regarding the causes and remedies of mental illness A qualitative method involving coded self-administered questionnaires administered to a sample of 90 university students to collecting data at the end of 2019. The survey evidence points that almost 50% of the respondents had contact with a mentally ill person suggesting that the significant number of the respondents experienced a first-hand encounter and knowledge of mental illness in their family and community. The findings show an overall greater science-based understanding of the causes of mental illness to be followed by recommended psychiatric treatments. The survey evidence indicates that the top three leading causes of mental illness in the context of Eritrea according to the respondents are brain disease (76%), bad events in the life of the mentally ill person (66%) and substance abuse or alcohol taking, smoking, taking drugs like hashish. (54%). The majority of the respondents have a very sympathetic and positive outlook towards mentally ill persons suggesting that mentally illness does not simply affect a chosen individual rather it can happen to anybody regardless of economic class, social status, ethnicity race and religion. Medical interventions cited by the majority of the respondents as being effective treatments for mental illness centered on the idea that hospitals and clinics for treatment and even cures for psychiatric disease. Changing perceptions of mental illnesses in Eritrea that paralleled the very caring and sympathetic attitudes of the sample university students would require raising public awareness regarding mental illness through education, using the mass media to raise public awareness, integrating mental health into the primary health care system, decentralizing mental health care services to increase access to treatment and providing affordable service to maintain positive treatment outcomes.
Effect of Phosphorus and Zinc on the Growth, Nodulation and Yield of Soybean ...Premier Publishers
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This study investigated the effects of phosphorus and zinc on the growth, nodulation, and yield of two soybean varieties in Nigeria. Phosphorus application significantly affected growth, nodulation, yield, and some yield components, with 60 kg P2O5/ha giving the highest growth and yield. Phosphorus also increased nodulation, with 30 kg P2O5/ha providing the highest nodulation. Zinc application did not significantly affect most growth characters or nodulation, except for reducing plant height. Phosphorus increased soybean yield significantly to 1.9 t/ha compared to the control of 1.7 t/ha. Protein and oil contents were not significantly affected by phosphorus but were by zinc
Influence of Harvest Stage on Yield and Yield Components of Orange Fleshed Sw...Premier Publishers
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A field experiment was conducted at Adami Tullu Agricultural Research Center in 2018 under rainfed condition with supplementary irrigation to determine the influence of harvest stage on vine yield and tuberous root yield of orange fleshed sweet potato varieties. The experiment consisted of four harvest stages (105, 120, 135 and 150 days after planting) and Kulfo, Tulla and Guntute varieties. A 4 X 3 factorial experiment arranged in randomized complete block design with three replications was used. Interaction of harvest stage and variety significantly influenced above ground fresh biomass, vine length, marketable tuberous root weight per hectare, commercial harvest index and harvest index. The highest mean values of above ground fresh biomass (66.12 t/ha) and marketable tuberous root weight (56.39 t/ha) were produced by Guntute variety harvested at 135 days after planting. Based on the results, it can be recommended that, farmers of the study area can grow Guntute variety by harvesting at 135 days after planting to obtain optimum vine and tuberous root yields.
Performance evaluation of upland rice (Oryza sativa L.) and variability study...Premier Publishers
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This study evaluated 13 upland rice varieties over two locations in Ethiopia for yield and other traits. Significant differences were found among varieties for several traits. The highest yielding varieties were Chewaka, Hiddassie, and Fogera 1. Chewaka yielded 5395.8 kg/ha on average, 25.8-35% more than the check. Most varieties matured within 120-130 days. High heritability was found for days to heading, panicle length, and grain yield, indicating these traits can be easily improved through selection. Grain yield also had high genetic variation and heritability with genetic advance, suggesting yield can be improved through selection. This study identified variability that can be used
Response of Hot Pepper (Capsicum Annuum L.) to Deficit Irrigation in Bennatse...Premier Publishers
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This study was conducted at Enchete kebele in Benna-Tsemay Woreda, South Omo Zone to evaluate the response of hot pepper to deficit irrigation on yield and water productivity under furrow irrigation system. The experiment comprised four treatments (100 % of ETc, 85% of ETc, 70 % of ETc and 50% of ETc), respectively. The experiment was laid out in RCBD and replicated four times. The two years combined yield results indicated that, the maximum total yield (20.38 t/ha) was obtained from 100% ETc while minimum yield (12.92 t/ha) was obtained from 50% of ETc deficit irrigation level. The highest WUE 5.22 kg/ha mm-1 was obtained from 50% of ETc. Treatment of 100% ETc irrigation application had highest benefit cost ratio (4.5) than all others treatments. Applying 50% of ETc reduce the yield by 37% when compared to 100 % ETc. Accordingly, to achieve maximum hot pepper yield in areas where water is not scarce, applying 100% ETc irrigation water application level throughout whole growing season under furrow irrigation system is recommended. But, in the study area water scarcity is the major limiting factor for crop production. So, it is possible to get better yield and water productivity of hot pepper when we apply 85% ETc irrigation water throughout growing season under furrow irrigation system.
Harnessing the Power of Agricultural Waste: A Study of Sabo Market, Ikorodu, ...Premier Publishers
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Nigeria is still burdened with huge responsibilities of waste disposal because the potential for benefits of proper waste management is yet to be harnessed. The paper evaluates the capacity of the Sabo Cattle market in producing the required quantities of waste from animal dung alongside decomposed fruits with a view to generating renewable energy possibilities for lighting, security and other business activities of the market. It is estimated that about 998 million tons of agricultural waste is produced yearly in the country with organic wastes amounting to 80 percent of the total solid wastes. This can be categorized into biodegradable and non-biodegradable wastes. The paper evaluates the capacity of the Sabo Cattle market in producing the required quantities of waste from animal dung alongside decomposed fruits with a view to generating renewable energy possibilities for lighting, security and other business activities of the market. The Sabo market was treated as a study case with the adoption of in-depth examinations of the facility, animals and products for sale and waste generated. A combination of experimental, interviews (qualitative) and design simulation (for final phase) was adopted to extract, verify and analyse the data generated from the study. Animal waste samples were subjected to compositional and fibre analysis with results showing that the sample has high potency for biogas production. Biodegradable Wastes are human and animal excreta, agricultural and all degradable wastes. Availability of high quantity of waste generated being organic in Sabo market allows the use of anaerobic digestion to be proposed as a waste to energy technology due to its feasibility for conversion of moist biodegradable wastes into biogas. The study found that at peak supply period during the Islamic festivities, a conservative 300tonnes of animal waste is generated during the week which translates to over 800kilowatts of electricity.
Influence of Conferences and Job Rotation on Job Productivity of Library Staf...Premier Publishers
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The general purpose of this study is to investigate the influence of conferences and job rotation on job productivity of library staff in tertiary institutions in Imo State, Nigeria. The survey research design was used for this study using questionnaire as an instrument for data collection. This study covered the entire population of 661. Out of these, 501 copies of the questionnaire representing 75.8% were duly completed and returned for analysis. Studentโs t-test was used to analyze the research questions. The finding showed that conferences had no significant influence on the job productivity of library staff in tertiary institutions in Imo State, Nigeria (F cal= 7.86; t-vale =6.177; p >0.005). Finding also showed that job rotation significantly influences job productivity of library staff in tertiary institutions in Imo State, Nigeria (F-cal value= 18.65; t-value = 16.225; P<0.05). This study recommended that, government should ensure that library staff participate in conferences with themes and topics that are relevant to the job they perform and also ensure that there should be proper evaluation and feedback mechanism which aimed to ensuring control and minimize abuse of their development opportunities. Again, there should be written statement of objectives in order to sustain job rotation programmes. Also, that training and development needs of library staff must be identified and analyzed before embarking on job rotation processes as this would help to build skills, competences, specialization and high job productivity.
Scanning Electron Microscopic Structure and Composition of Urinary Calculi of...Premier Publishers
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This document summarizes a study on the scanning electron microscopic structure and chemical composition of urinary calculi (stones) found in geriatric dogs. Microscopic examination of urine samples revealed increased numbers of blood cells, epithelial cells, pus cells, casts, bacteria and crystals of various shapes, predominantly struvite, calcium oxalate dihydrate and monohydrate, and ammonium urate. Scanning electron microscopy showed perpendicular columnar strata of struvite crystals and wavy phases of uric acid. Chemical analysis identified calcium phosphate, calcium oxalate and urea stones. The study characterized the microscopic and electron microscopic appearance of crystals and chemical composition of urinary calculi in geriatric dogs.
Gentrification and its Effects on Minority Communities โ A Comparative Case S...Premier Publishers
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This paper does a comparative analysis of four global cities and their minority districts which have been experiencing the same structural pressure of gentrification. The main contribution of this paper is providing a detailed comparison of four micro geographies worldwide and the impacts of gentrification on them: Barrio Logan in San Diego, Bo-Kaap in Cape Town, the Mission District in San Francisco, and the Rudolfsheim-Fรผnfhaus District in Vienna. All four cities have been experiencing the displacement of minority communities due to increases in property values. These cities were chosen because their governments enacted different policies to temper the gentrification process. It was found that cities which implemented social housing and cultural inclusionary policies were more successful in maintaining the cultural and demographic make-up of the districts.
Oil and Fatty Acid Composition Analysis of Ethiopian Mustard (Brasicacarinata...Premier Publishers
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The experiments was conducted at Holetta Agricultural Research Center, to analyze forty nine Ethiopian Mustard land races for oil and fatty acid composition traits The experiment was carried out in a simple lattice design. The analysis of variance showed that there were highly significant differences among genotypes for all oil and fatty acid traits compared. The significant difference indicates the existence of genetic variability among the land races which is important for improvement
A Free 200-Page eBook ~ Brain and Mind Exercise.pptxOH TEIK BIN
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(A Free eBook comprising 3 Sets of Presentation of a selection of Puzzles, Brain Teasers and Thinking Problems to exercise both the mind and the Right and Left Brain. To help keep the mind and brain fit and healthy. Good for both the young and old alike.
Answers are given for all the puzzles and problems.)
With Metta,
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Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
1. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
IJPBCS
Genotype by environment interactions and effects on
growth and yield of cowpea varieties in the rainforest
and derived savanna agroecologies of Nigeria
*Agele, S.O1, Oyewusi, I.K2, Fayeun, L3 and Famuwagun, I.B4
1,2,3,4
Department of Crop, Soil & Pest Management, Federal University of Technology, Akure, Nigeria
Cowpea is widely grown in the humid tropics as staple and is largely affected by genotype by
environment interaction (GEI). Data obtained from field trials were subjected to genotype (G) by
environment (E) interaction (GEI Biplot) analysis and was applied to examine the nature and
magnitude of GEI and quantify their effects on cowpea performance in seven experimental trials
in a rainforest and derived savanna agroecologies of south-west Nigeria. Results showed that
genotype x environment interactions effects were significant on cowpea growth and yield
characters. The differential performance of cowpea varieties as early- and late- rainy season crops
at both locations were attributable to variability in the soil, weather and biotic factors of the test
environments. Determination of winning genotype(s) and yield ranking across environments
showed that cowpea varieties depicted differential performance for the test environments and
hence the interaction was crossover type. Varieties IT97K-568-18, IT97K-568-18 and Oloyin Brown
are high yielding while IT96D-610 and IT98K-205-8 are poor. Oloyin Brown and IT98K-573-2-1 won
in Akure 1, 2, 3 and 4 and Ado 1 while IT97K-568-18 won in Ado 2 and Akure 5. IT96D-610 and
IT98K-205-8 did not win in any environment. The best performing varieties, Oloyin Brown, IT97K-
568-18 and IT98K-573-2-1 combined both high yield and stable performance across test
environments and were characterized as ideal genotypes while most unstable variety, IT96D-610,
performed poorly in test environments. It is concluded that Ado-Ekiti was best for the late rainy
while Akure location was best for early rainy season cropping.
Keywords: Legumes, genotypes, soil, weather, yield, stability.
INTRODUCTION
Cowpea (Vigna unguiculata L Walp), is a food legume
which plays a major role in human nutrition in the tropics.
Its edible seeds provide cheap alternative source of
protein compared to animal protein. Cowpea is a major
grain legume crop in tropical and subtropical regions. This
region is characterized by large seasonal variations in soil
moisture regimes, soil and air temperatures (IITA, 2000).
The humid rainforest zone of Nigeria is characterized by
bi-modal rainfall distribution and variability of the average
date of onset of the rains than its cessation (Agele et al.,
2004). A cropping opportunity is provided by the earlier
part of the rainy (first sowing) season before the rainfall is
fully established. According to IITA (2000), the optimal
sowing date of grain legumes including cowpea in the
rainforest zone of Nigeria is at the beginning of the rains
and not when rainfall has fully established while the cropโs
reproductive growth phase particularly seed maturity falls
into the short dry spell which marks the end of the first
*Corresponding Author: Samuel O. Agele, Department of
Crop, Soil & Pest Management, Federal University of
Technology, Akure, Nigeria. Email: ohiagele@yahoo.com:
soagele@futa.edu.ng; Tel: + 234 803 5784 761
International Journal of Plant Breeding and Crop Science
Vol. 5(2), pp. 370-382, July, 2018. ยฉ www.premierpublishers.org. ISSN: 2167-0449
Research Article
2. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Agele et al. 371
modal rainfall. The dry spell is characterized by abundant
sunshine and negligible cloud overcast sky. The late
sowing season falls within the second mode of rainfall
distribution. However, the late season (late August/early
September to December), is occasioned by limiting soil
moisture status, extreme high soil temperatures, high
irradiance and atmospheric vapour deficits (Agele et al.,
2004). There are variations in soil water and thermal
regimes of the early part of the rainy season (early
vegetative phase of growth) and in the later part of the late
cropping season (terminal drought situation). These
environmental events have profound influence on growth
and yield of crops (Agele et al., 2004, Agele and Agbi,
2012).
The yielding ability of crop varieties is the ultimate result of
favorable interaction of genotype with the environment.
Environmental factors such as moisture content, time of
sowing, air temperature and photoperiod length, soil
characteristics differ across years and locations with
profound influence at developmental stages while different
responses and performance of genotypes observed in
environment are desirable characteristic (Gauch et al.,
2008). Poor yield in cowpea may be due to unavailability
of high yielding and stability of genotypes along with
appropriate advance agronomic management practices
(Agele and Agbi, 2012). Several varieties with high seed
yield potential and growth habit like early maturity were
identified and evaluated in adaptation trials to study seed
yield stability in different ecological zones (IITA, 2000).
There is therefore great need to test adaptation among
cowpea cultivars to environmental conditions of the
seasons of sowing and location in the ecological zones of
Nigeria.
Genotype by environment interactions are common for
most quantitative traits of economic importance.
Therefore, advanced breeding materials must be
evaluated in multiple locations for more than one year.
Genotype by environment interactions may be due to i.
heterogeneity of genotypic variance across environments
and ii. imperfect correlation of genotypic performance
across environments. Specific adaptations can make the
difference between a good variety and a superb variety.
Some environmental variation is predictable, they can be
attributed to specific, characteristic features of the
environment such as soil type, soil fertility, plant density.
Some variation is unpredictable e.g., rainfall, temperature,
humidity. The stability of performance across
environments may depend upon the magnitude of
genotype x environment interaction. A genotype is
considered to have agronomical stability if it yields well
with respect to the productive potential of the test
environment. Stable genotypes are defined as the cultivar
that makes the smallest contribution to the genotypes x
environment interaction (G x E) (Eberhert and Russell,
1996), model had been widely used to study stability
parameters through genotypes x environment interaction
i.e. mean seed yield and regression coefficient. The
present research work deals with the determination of
seed yielding ability, magnitude and nature of genotype x
environment interaction and stability characteristics of six
cowpea varieties tested under different environmental
conditions.
Several methods of analysing GE have been reviewed
(Gauch et al., 2008). Some methods, such as analysis of
variance, are good at determining GE but cannot
determine the pattern of the interactions. The strengths of
methods of genotype by environment interaction (G x E)
analysis has been debated (Yan et al., 2007; Gauch et al.,
2008; Yang et al., 2009). Regression-based methods use
environmental scores, which have less to do with genotype
plus GE (GE) and thus explain only a small part of GE. In
the recent past, statistically effective methods, such as
biplots based on Principal Component (PC) analysis, have
been developed for GE analysis (Gauch 1993; Crossa et
al. 2002; Yan and Kang 2002). Biplot analysis is a
multivariate technique that graphically displays two-way
data to permit visualization of the interrelationship (Gauch
1993, 2006; Yan and Tinker 2006). The biplot is a
graphical presentation of a genotype by environment two-
way table (Gauch 1993, 2006, 2013). The GE biplot can
be subjected to different ways of singular value partitioning
(SVP) (Yan and Tinker 2006). The biplot model that is fitted
to residuals after the removal of the environmental main
effect (environment-centered data) is called a GE biplot
(Crossa and Cornelius 1997; Yang et al., 2009). The GE
biplot is useful in evaluating the genotype main effects plus
the GE (Yan and Tinker 2006). This approach has been
commonly used for delineating crop performance in
different environments and for varietal recommendations
(Yan and Tinker 2006, Yang et al., 2009).
The GGE refers to the main genotypic effect (G) and the
genotype x environment interaction (GE), which are the
two most important sources of variation for cultivar
evaluation in a multi environment trials (Yan et al., 2007).
The GE biplot displays the genotype main effect (G) and
genotype by environment interaction (GE) of a genotype-
by-environment dataset (Yan et al., 2000). GE biplot is
specially and perfectly used for mega-environment
analysis based on genetic correlation between
environment and the which-won-where pattern; test
environment evaluation based on their discriminating
ability and representativeness; and genotype evaluation
based on their mean performance and stability across a
mega-environment (Crossa et al., 2002; Yan et al., 2000).
However, the GE biplot is capable of capturing much of the
G plus GE variation and is also useful in understanding the
test environment effects required for rationalizing scarce
resources in crop breeding programs (Yan and Tinker
2006).
The objectives of this study were to examine the nature of
genotype by environment interaction (GEI) and to quantify
3. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Int. J. Plant Breed. Crop Sci. 372
the effects of its magnitude on cowpea in seven
experimental trials for three consecutive years (2013-
2015) and use the GE biplots to identify superior cowpea
varieties for test environments of the rainforest and derived
savanna agroecologies in south western Nigeria.
MATERIALS AND METHODS
Materials
Six cowpea varieties (IT98K-205-8, Ife brown, IT96D-610,
IT98K-573-2-1, Oloyin brown, IT97K-568-18) were
planted in the early and late rainy seasons of 2013-2015
at Akure and Ado Ekiti of the rainforest and derived
savanna agroecologies of south west Nigeria.
Methods
Data obtained from the field trials were subjected to
genotype (G) by environment (E) interaction (GxE Biplot)
analysis and was applied to examine the nature and
magnitude of GEI and quantify their effects on cowpea
performance in seven experimental trials. The seven
environments were made up of 2 seasons (early and late
rainy seasons) + 2 locations (Akure and Ado Ekiti
locations) + 3 years (2013-2015).
At maturity, the yield parameters of 100 seed weight, days
to 50% flowering, shoot biomass and seed yield were
collected and subjected to analysis of variance following
stability parameters on variety, environment and variety x
environment. This statistical analysis enables the
determination of varietal stability in performance under the
environmental conditions of the locations evaluated. Grain
yield data were subjected to combined analysis of variance
using SAS GLM (SAS, 2004) to examine the main effects
of the environment (E) and genotypes (G) and their
interactions (GE) variances. Further partitioning and
analysis of the GE was computed using the GGE model
(Yan, 2001). The Gollobโs (1968) F-test showed that the
two principal components of the biplot were significant and
thus could explain much of the variation (67%) in the two-
way data (Zobel et al. 1988; Gauch 2006). Therefore, the
GGE biplot was constructed using the first two principal
components (PC1 and PC2) derived from yield data
subjected to environment effects (Yan et al., 2000, Yan
and Tinker 2006)). The GE-2 biplot analysis was
conducted using Genstat Software version 13 (Genstat
2010).
The GGE biplot model used was described by Yan et al.
(2000), Yan and Hunt (2001) and Yan (2002) as:
๐๐๐ โ ๐ โ ๐ฝ๐ = ๐1๐๐1๐๐1 + ๐2๐๐2๐๐2 + ๐๐๐ โฆโฆโฆโฆ(1)
where Yij is measured mean yield of the ith genotype
i(=1,2,โฆ.,n) and jth environment j(=1,2โฆ,m), ฮผ is the
grand mean, ฮฒj is the main effect of environment j, ฮผ + ฮฒj
being the mean yield across all genotypes in environment
j, ฮป1 and ฮป2 are the singular values (SV) for the first and
second principal component (PC1 and PC2), respectively,
ฮพi1 and ฮพi2 are eigenvectors of genotype I for PC1 and
PC2, respectively, ล1j and ล2j are eigenvectors of
environment j for PC1 and PC2, respectively, ฮตij is the
residual associated with genotype i in environment j. PC1
and PC2 eigenvectors cannot be plotted directly to
construct a meaningful biplot before the singular values
are partitioned in to the genotype and environment
eigenvectors.
Singular value partitioning was implemented by:
๐๐1 = ๐1๐1 ๐๐1 ๐๐๐ ๐๐๐ = ๐11โ๐1 ๐๐๐ โฆโฆโฆโฆโฆ(2)
where f1 is the portion factor for PC1. The f1 can range
between 0 and 1. To visualize relationship among
genotypes, the GGE biplot based on genotype metric (that
is, f=1; S.V.P=1) is appropriate and environment metric
(f=0; S.V.P=2)
If the data were environment-standardized, the common
formulae to generate the GGE biplot was as follows:
๐๐๐ โ ๐ โ ๐ฝ๐ ๐ ๐ = ๐๐1๐1๐ + ๐๐๐ ๐๐=1 โฆโฆโฆโฆ..(3)
where sj is the standard deviation in environment j, i=1,
2,.,โฆ k, gi1and e1j are PC1 scores for genotype i and
environment j, respectively. In the present study we used
environment standardized model, Equation (3).
The which-won-where scatter biplot (for mega-
environment delineation), genotype comparison biplot (for
comparing genotypes based on mean yield and stability)
and location comparison biplot (for identifying the most
discriminating and representative locations) were
generated using the appropriate SVP methods (Yan
2002).
In the scatter biplot, the polygon view displaying the which-
won-where pattern was formed by connecting the
genotype markers furthest away from the biplot origin such
that the polygon contained all other genotypes (Yan 2002).
The polygon was then dissected by straight lines
perpendicular to the polygon sides and running from the
biplot origin. Visualization of the mean and stability of
genotypes using a genotype comparison biplot was
achieved by representing an average environment by an
arrow. The relative performance of cowpea genotypes was
ranked. A line that passes through the biplot origin to the
average environment (average genotype axis) was drawn
followed by a perpendicular line that passes through the
biplot origin. The line passing through the biplot origin is
called the average tester coordinate (ATC). The double
arrow line which is perpendicular to ATC and passes
through the origin represents stability of genotypes. An
ideal genotype should have the highest mean performance
and be absolutely stable. The relative yield of cowpea
genotypes were ranked based on length of their
4. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Agele et al. 373
projections onto perpendicular line from each genotype
towards test environment axes. Rank increases as one
goes to the positive end.
For the analyses of test location, the environment vectors
were drawn from the biplot origin to the markers of the
environment. The average environment (AE) was
represented with a small arrow and a line from the biplot
origin to the AE (average environment axis) was drawn
followed by a perpendicular line that passes through the
biplot origin. For each genotype, the grand means of all
traits across environments that include yield and yield
components and days to physiological maturity were
calculated. This formed a two-way table of genotypes and
traits means. The cross environment mean data were
scaled (standardized) by dividing each trait mean value
with the within-trait standard deviation, as outlined by Yan
and Tinker (2006). The standardization helps to remove
the different units found among different traits (Yan et al.
2000; Yan 2001). The resultant data were subjected to
biplot analysis using the trait focused SVP method and the
data were trait centered. The vectors were drawn to
connect the specific traits from the biplot origin. The
across-environment means of the seven traits studied
were subjected to Pearsonโs phenotypic correlation
coefficient analyses using Genstat software
RESULTS
G by E and test environment evaluation
The genotype by environment interaction (GEI) biplots
analysis showed that the performance of cowpea
genotypes at the test environments differed and hence the
interaction was crossover type. Cowpea varieties Oloyin
Brown, IT97K-568-18 and IT98K-573-2-1 combined both
high mean yield and high stability performance across the
test environments and could be characterized as well
adapted while the most unstable variety with poor
performance across locations was IT98K-205-8. The
combined analysis of variance over environments showed
that cowpea seed yield was significantly (p<0.001)
affected by environments (E), genotypes (G) and genotype
by environment interactions (Table 1). Environment
accounted about 26 % of the variation while GEI explained
about 60 % of the variation which is more than double of
the environmental and four times of the genotypic effects
of the total variation. As shown by differential yield ranking
of genotypes, the GE was crossover type and test-
environment that effectively identify superior genotypes
were identified.
Yield and stability performance of cowpea varieties
Fig. 1 to 8 present polygon view of six genotypes under
seven environments from which a โwhich-won-whereโ
pattern was observed. The ranking of cowpea genotypes
based on both mean yield and stability relative to an ideal
genotype in test environments are presented in Fig. 1.
Cowpea varieties IT98K-573-2-1, IT97K-568-16 and
Oloyin Brown in that order, when placed in the center of
the concentric circle were considered as ideal genotypes
(most stable across test environments) having highest
mean yield across the test environments. Other genotypes
based on distance from ideal genotype which were ranked
unfavourable as they were most far from the ideal
genotype were Ife Brown and IT98K-205-8,IT96D-610.
Ranking genotypes relative to the highest yielding
environment
The two locations Akure and Ado Ekiti, used to evaluate
cowpea genotypes and their ranking as presented in the
figures. The relative yield of cowpea genotypes were
ranked based on length of their projections onto
perpendicular line from each genotype towards test
environment axes. Rank increases as one goes to the
positive end. Hence, Three genotypes, IT98K-573-2-1,
IT97K-568-568-18 and Oloyin Brown were regarded as the
best yielding genotype had yields above average, while
other genotypes yielded below the average performance.
Figure 1 shows the results of six tested cowpea varieties
and their yield performance in the test environments. The
result shows that IT98K-205-8 performed best in Akure 5
(75.9kh/ha) while Ife Brown and IT96D-610 performed
best in Ado 2 (87.4kg/ha) and Akure 1 (54.8kg/ha).
Cowpea variety IT98K-573-2-1, Oloyin Brown and IT97K-
568-18 performed best in Ado 1 (108.2,148.6, 83.5kg/ha).
In contrast, IT98K-205-8 gave the poorest yield in Ado 1
(13.4kg/ha) while Ife Brown, IT96D-610, IT98K-573-2-1,
Oloyin Brown and IT97K-568-18 gave the poorest
performance in Ado 4 (9.4, 9.2,11.7,15.8,13.4 kg/ha)
respectively. IT96D-610 gave the poorest mean yield
among the tested cowpea varieties (33.7kg/ha) while the
best performing variety with the highest mean yield was
Oloyin Brown (58.8 kg/ha).The highest yielding
environment for all tested varieties was Ado 1. Most of the
varieties were unstable across all environments, however,
Oloyin Brown, IT97K-568-18 and IT98K-573-2-1 were
fairly stable .The result depicted that the performance of
cowpea genotypes were different at different testing
environments.(Different winners at different environments)
due to the existence of large GE interactions as revealed
by different yield ranking of genotypes.
Genotype Evaluation Based on GEI Biplots
The first two principal components for mean performance
and stability among grain yield (PC1 and PC2) of the GGE
explained 84 % with PC1 = 69.5 and PC2 = 14.7 of the
GGE sum of squares using environment standardized
model. Cowpea varieties, IT97K-568-18, IT98K-573-2-1
and Oloyin Brown are high yielding, in contrast, Ife Brown,
IT98K-205-8 and IT96D-610 were generally poor yielding
varieties (Fig. 1 and 2). Although, Oloyin Brown and
5. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Int. J. Plant Breed. Crop Sci. 374
IT98K-573-2-1 are high yielding varieties while Ife Brown
and IT98K-205-8 are poor yield varieties and unstable
Oloyin Brown and IT98K-573-2-1 performed best in Akure
1, Akure 2, Akure 3, Akure 4 and Ado 1 while IT97K-568-
18 performed best in Ado 2 and Akure 5. However, Ife
Brown, IT98K-205-8 and IT96D-610 did not win in any of
the tested environments (Fig. 3). Cowpea variety had the
shortest days to attain 50% flowering and mature earlier.
Although, IT98K-205-8 and Ife Brown are unstable, they
had the shortest days to attain 50% flowering and mature
earlier among the tested varieties. Oloyin Brown, IT98K-
568-18 took longer days to attain 50% flowering and are
late maturing varieties. The which-won varieties analysis
is presented in Fig. 4. IT96D-610 won in Akure 1 and Ado
2 while Ife Brown and IT98K-573-2-1 won in Akure
3,IT96D-610 won in Ado 2 and Akure 1,Oloyin Brown won
in Akure 2 while IT98K-205-8 won in Akure 4, Ado 1 and
Akure 5 and is early maturing. Cowpea varieties IT98K-
573-2-1, IT97K-568-18 and IT96D-610 are high yielding as
they gave the highest seed number across environment
(Fig. 5). In contrast, Ife Brown and IT98K-205-8 are
unstable with poor seed producing abilities across
environments. Oloyin Brown and IT98K-573-2-1 won in,
Ado 2, Akure 2, Akure 3, Akure 5 and Akure 1 and
similarly, IT97K-568-18 won in Akure 4 (Fig. 6). Cowpea
varieties Oloyin Brown, IT98K-205-8 and IT98K-205-8
produced heaviest seeds while in contrast, Ife Brown,
IT96D-610 is unstable across all environments (Fig. 7). In
terms of seed weight, cowpea varieties of Oloyin Brown,
IT97K-568-18 and IT98K-573-2-1 won in Akure 3, Akure 5
and Ado 1 respectively while Ife Brown won in Akure 1
(Fig. 8 ).
In general, yield and yield stability evaluation among the
cowpea varieties showed that the varieties differed in their
adaptable and stability of yields in the test environments
(location, season). However, varieties Oloyin Brown
expressed high yield potential in the study areas. The test
environment and location effect fell into two sections
where most of the tested varieties where not stable while
others were found to be suitable to the tested
environments. In the biplot analysis, Ife Brown, IT98K-205-
8 and IT96D-610 were vertically distant apart; however,
they did not fall close to the horizontal line. This implies
that these varieties lack stability but could be of high yield
potential in favourable environments. The greater the PCA
scores, the more specifically adapted is a genotype to
certain environments while the more the PCA scores
approximate to zero, the more stable or adapted the
genotype is in the environments tested. The genotype
main effect plus GE biplot showed that the cowpea
varieties Oloyin brown, IT97K-568-18 and IT98K-573-2-1
combined both high yield and had high stability
performance across the test environments in addition to
other desirable agronomic traits. These varieties can be
characterized as well adapted to the test environments.
The most unstable varieties with poor performance across
location was IT96D-610 and IT98K-205-8. Evaluation of
cowpea yield stability showed that the varieties differed in
their adaptability and stability of yields in the test
environments (location, season and years). However,
Oloyin Brown expressed high yield potential in the study
locations. The test environment and location effect fell into
two sections where most of the tested varieties where not
stable while others were found suitable and ideal to the
tested environments. In the biplot analysis, Ife Brown,
IT98K-205-8 and IT96D-610 were vertically distant apart;
however, they did not fall close to the horizontal line. This
implies that these varieties lack stability but could be of
high yield potential in favourable environments. Based on
the analysis, Oloyin Brown, IT97K-568-18 and IT98K-573-
2-1 were well adapted to high yielding environments
DISCUSSION
The genotype by environment interaction analysis
demonstrated that cowpea varieties responded differently
to environmental conditions of the study area. The
combined analysis of variance showed highly significant
differences among varieties,environments and varieties by
environment interractions for grain yield.The stability study
indicated that among the tested varieties,most were found
unstable. The result further gave credence to the fact that
cowpea grain yields were affected by environment and
their interactions. The results show that IT97K-568-18,
IT97K-568-18 and Oloyin brown are high yielding while
IT96D-610 and IT98K-205-8 are poor yielding. The result
also indicated that Oloyin brown and IT98K-573-2-1 won
in Akure 1, Akure 2, Akure 3, Akure 4 and Ado 1 while
IT97K-568-18 won in Ado 2 and Akure 5.IT96D-610 and
IT98K-205-8 did not win in any environment. In contrast,
IT98K-573-2-1, IT97K-568-18 and Oloyin brown showed
high yield potential in favourable environments. The
differences among varieties in terms of direction and
magnitude along the X-axis (yield) and Y axis (IPCA1
scores) are important. In the biplot display, cowpea
varieties in environment that appear almost on a
perpendicular line of a graph had a similar mean yields and
those that fall almost on a horizontal line had similar
interaction (Crossa et al., 1990). Genotypes or
environments with large negative or positive PCA scores
denoted high interactions, while those with PCA1 scores
near zero (close to the horizontal line) have little interaction
and vice versa across environments (Crossa et al., 1990).
In the biplot, the varieties Ife Brown, IT98K-205-8 and
IT96D-610 were vertically distant apart; however, they did
not fall close to the horizontal line. This implies that these
varieties lack stability but could be of high yield potential in
favourable environments. The greater the PC scores, the
more specifically adapted is a genotype to certain
environments (Sanni e et al., 2009). However, varieties of
Oloyin Brown, IT97K-568-18 and IT98K-573-2-1 were well
adapted to high yielding environments.The ranking of six
cowpea genotypes based on their mean yield and stability
performance was performed. The line passing through the
biplot origin is called the average tester coordinate (ATC)
while the double arrow line which is perpendicular to ATC
6. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Agele et al. 375
and passes through the origin represents stability of
genotypes. An ideal genotype should have the highest
mean performance and be absolutely stable (Yan and
Kang, 2003). The relative adaptation of genotypes was
studied and genotypes were ranked based on length of
their projections onto the axes. Rank increases as one
goes to the positive end (Yan et al., 2000). The genotype
comparison biplot showed that the most stable and high-
yielding genotype are Oloyin Brown, IT97K-568-18 and
IT98K-573-2-1. These three genotypes yielded higher and
were more stable than the commercial variety, Ife Brown.
Based on their stability and high yield from these varieties
were outstanding in the two locations and environments.
Such varieties will display stability and outstanding yield
performance in high yield environments, which is highly
desirable. Genotypes Oloyin Brown, IT97K-568-18 and
IT98K-573-2-1 were comparable in yield to Ife Brown,
other varieties did not perform well Ife Brown was ranked
least in terms of performance and stability. The top three
genotypes which performed well in specific environments,
could be targeted to those environments to maximize grain
yield.
The nature of the GE estimates as indicated by significant
genotype main effect and suggest differential responses of
the genotypes and the need to identify high-yielding and
stable genotypes across the test environments. In the
locations (agroecological zones) of study, there are
differences in predictable factors (soil characteristics) and
unpredictable factors (temperature and rainfall). The
presence of GE that is several folds larger than the
genotypic main effects indicates substantial differences in
genotypic responses across locations. Bernardo (2002)
asserted that when the GE is substantial it should not be
ignored; the causes must be identified (Yan and Kang
2002) and the GE should be addressed. Most of the GE
variation in this study was due to predictable factors
(location-intrinsic factors) rather than unpredictable factors
(years). In this study, the GE could be attributed to
differences in soil types, rainfall patterns, and
temperatures as well as various pests found in specific
locations. Under such circumstances, predictable factors
can be managed, but modifying the environment to suit the
crop will further constrain the resource-poor farmers. The
cheaper option is to develop cowpea varieties adapted to
the target environments. However, because the locations
have no clearly defined boundaries, farmers need to have
informed choices of variety to grow. The development of
varieties with broad adaptation is more important rather
than location-specific varieties. Multi environment analysis
using GE biplot produces best polygons to view or
visualize the genotype x environment interaction pattern
(Yan and Kang, 2003). Visualization of the โWhich-won-
whereโ pattern in the polygon view is helpful to estimate
possible existence of different mega-environments in the
target environment (Yan and Rajcan, 2002; Yan et al.,
2000; Yan and Tinker, 2006). Hence, Akure and Ado Ekiti
can be considered as separate location for cowpea variety
evaluation and recommendation. A similar result has been
documented for soybean by Asfaw et al. (2009).
The cowpea genotypes were evaluated across
environments. The results showed that the seven
environments were best predicted by the first two PCAs
based on Gollobโs F-test (Zobel et al., 1988). Therefore, a
biplot with two PCAs was used to describe the GGE. Yan
(2000) reported that the first two PCs captured the most
useful variation in a biplot. When the GE is larger than the
genotype main effect, ignoring the interaction is not
recommended (Yan and Kang 2002). In our study, the
GGE biplots explained 67 % of the total GGE sum of
squares, while G plus GE explained over 50 % of the total
variance. The results of the environments showed that the
environments are discriminating of the genotypes Thus,
Oloyin Brown, IT97K-568-18 and IT98K-573-2-1 were the
most discriminating of the genotypes. Hence, Akure and
Ado Ekiti were more representative environments for
cowpea multi location trials and ideal for selecting cowpea
genotypes for the south west Nigerian agroecologies. The
success of different genotypes in different environments
shows the existence of crossover genotype by
environment interactions (Yan and Tinker 2006). The
environments overlap suggesting the absence of a clear
pattern of GEs. The existence of crossover GE suggests
that cultivar evaluation and recommendation based on any
single location is unreliable because there is differential
performance of varieties across locations (Yan and Kang
2002). The existence of crossover interactions also
suggests the need to reduce or exploit GE. For crossover
genotype by environment interaction, Yan and Kang
(2002) suggested that cultivar evaluation should be based
on mean performance and stability. The results of the
evaluation of the Test Environments showed that the
presence of GE in cowpea (discriminating ability of the
location; Yan and Tinker 2006) justifies undertaking the
multi-location and multi-year trials. Therefore,
environmental analysis will help to better understand the
testing environments and possibly help reduce the cost of
genotype evaluations (Yan and Kang 2002). The large GE
effect suggests the possible presence of different
environments with different winner genotypes (Yan and
Kang, 2003). Similar result was obtained for soybean in
Nigeria by Jandong et al. (2011). These reports depicted
that the performance of crop genotypes which may be
different at different testing environments (different
winners at different environments) may be due to the
existence of large GE interaction. Test environments have
different winner genotypes. This situation complicates
selection process and cultivar recommendation in
breeding programs (Comstock and Moll, 1963, Yan et al.,
2007). Existence of significant and large GE in legumes
such as cowpea in Africa has been reported (Asfaw et al.,
2009; Gurmu et al., 2009; Tukamuhabwa et al., 2012;
Bueno et al., 2013).
7. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Int. J. Plant Breed. Crop Sci. 376
CONCLUSIONS
Cowpea is widely grown in the humid tropics as a staple,
however, in this region, it is largely affected by genotype
by environment interaction (GEI), making it difficult and
expensive to select and recommend new genotypes for
different environments. The nature, magnitude and effects
of genotype by environment interaction (GEI) on the
growth and yield characters cowpea varieties in early- and
late- rainy seasons, at 2 locations (Akure and Ado Ekiti )
and 3 years (2013-2015) was quantified. The results
depicted differential performance of cowpea genotypes at
different test environments and hence the interaction was
crossover type. The GEI explained about 60 % of the
variation which is more than double of the environmental
and four times of the genotypic effects of the total variation.
Varieties Oloyin Brown, IT97K-568-18 and IT98K-573-2-1
exhibited both high yield and stability across the test
environments and could be characterized as ideal while
the most unstable varieties with poor performance are
IT98K-205 and IT96D-610. The study identified superior
cowpea genotypes for tested locations (Akure and Ado
Ekiti environments) an information which denotes the
value of the tested locations for future cowpea breeding
activities. It is concluded that cowpea varieties produced
high seed yield as early and late rainy season crops at both
locations. Ado-Ekiti location was best for the late rainy
season while Akure location was best for the early rainy
season.
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APPENDIX
Table 1: Analysis of variance for grain yield (kgha-1) of six varieties evaluated at five experimental trial and two locations
for three consecutive years between 2013-2015 in (Akure and Ado-Ekiti)
Source of variation df SS MS F-value %SS
Environment (E) 6 3230932 538489 7.40 25.58
Genotype (G) 5 3322940 664588 9.10 14.87
Replicate (R) 2 2585297 1292649 17.7
GE 30 3747387 124913 1.77 59.55
Error 10 3489186 348919
Total 53 3876567 73143
GE = Genotype x Environment interaction; DF =Degree of freedom; SS =Sum of squares; MS =Mean square
Figure 1. Performance and stability of seed yields among cowpea varieties in seven environments on two
principal components (PC1 and PC2).
10. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Agele et al. 379
Figure 2: Polygon view of the GGE biplot showing which cowpea variety won and in which environment: seed
yield
Figure 3: Performance and stability of cowpea varieties in environments of the early and late rainy season
conditions on two principal components (PC1 and PC2) in terms of days to 50% flowering
11. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Int. J. Plant Breed. Crop Sci. 380
Figure 4: Polygon view of the GGE biplot showing which cowpea variety won and in which environment : 50%
flowering date
Figure 5: The performance of cowpea varieties for stability across environments on two principal components
(PC1 and PC2) in terms of in number of seeds per plant
12. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Agele et al. 381
Figure 6. Polygon view of the GGE biplot showing which cowpea variety won and in which environment on two
principal components (PC1 and PC2) in terms of number of seeds per plant
Figure 7. The ranking of cowpea varieties for stability in 100 seed weight across environments of on two principal
components (PC1 and PC2)
13. Genotype by environment interactions and effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria
Int. J. Plant Breed. Crop Sci. 382
Figure 8: Polygon view of the GGE biplot showing which cowpea variety won and in which environment: 100 seed
weight
Accepted 20 September 2017
Citation: Agele, S.O, Oyewusi, I.K, Fayeun, L and Famuwagun, I.B (2018). Genotype by environment interactions and
effects on growth and yield of cowpea varieties in the rainforest and derived savanna agroecologies of Nigeria.
International Journal of Plant Breeding and Crop Science, 5(2): 370-382.
Copyright: ยฉ 2018. Agele et al. This is an open-access article distributed under the terms of the Creative Commons
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