Abstract— An investigation into the effects of low light (meanPPFD169-493Ms-1m-1), red light (meanPPFD657-843Ms-1m-1) and normal light (meanPPFD1061-1260Ms-1m-1) on physiological changes including yield attributes, nutritional status at Panicle initiation (PI), flowering and harvest stages in winter rice (genotype: Monoharsali) was carried out from 40 days after transplanting (DAT) to crop maturity under both pot and field conditions. There was reduction in available PPFD at flowering as compared to PI stage of the crop. The genotype exhibited significantly higher total dry matter (TDM) and lower leaf area index (LAI) values at normal light or red light than at reduced light situation. The bio-economical yield and harvest index (HI) under normal light exceeded those at low light regime. The yield attributes viz., number of panicles, number of field grains per panicle, 1000 grain weight (test weight), high density (HD) grains, potential 1000 grain weight and sink capacity were superior at normal or red light to low light condition. Higher the total carbohydrate contents in grains, higher were the sink capacity with the normal /red light illuminations at harvest stage. At PI stage, leaf nitrogen content was reduced by low light, but it increased at flowering stage significantly. Grain protein contents, under normal/red light exceeded its value at low light treatment. A positive correlation of most of the yield attributes with grain yield at normal/red light, and a negative correlation of these parameters were found at low light conditions.
Germination percentage and growing behavior of Salix tetrasperma (Willow) as ...Innspub Net
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/
Contributers: Norman Uphoff, CIIFAD, Cornell University, USA
Iswandi Anas, Biotechnology Lab, IPB, Indonesia
O.P. Rupela, former Principal Scientist, ICRISAT, India
A.K. Thakur, Directorate of Water Management, India
T.M. Thiyagarajan, Tamil Nadu Agric. Univ., India
Presented at: Conference of Association of Applied Biologists on Positive Plant-Microbial Interactions
Effect of some abiotic factors on the concentration of β- sitosterol of Prunu...Innspub Net
Prunus africana is a medicinal plant which develops in the mountains of several African countries. β-sitosterol can be used as a marker for the control of the product quality of the aforementioned plant in terms of phytotherapy. Farmers and public authorities do not have information on the influence of altitude and chemical characteristics of soils on the concentration of β- sitosterol of P. africana. To contribute to solve the problem, this research, carried out in Cameroon, aims to appreciate the effect of abiotic factors on the above phenotypic character. In nine composite samples of barks taken at different altitudes, the
concentration of β-sitosterol is appreciated via qualitative analyses by Thin Layer Chromatography, High Performance Liquid Chromatography and quantitative analyses by Gas Chromatography coupled with the Mass Spectrometry. The chemical analyses of soils taken under the stems of the aforementioned trees were made. The statistics were carried out using the SAS software. The concentration of β-sitosterol in each population of P. africana varies from zero to 38.65 μg/ml. There is
variability between the averages of the aforementioned concentration with respect to altitude and chemical elements of the soils but the differences are not significant. The Ascending Hierarchical Clustering distributes populations into three groups. These
tools obtained are indispensable for the ground management, the products exploited from this tree species and the production of seeds for creating forest and agro-forest plantations.
Seasonal growth patterns of Arundo donax L. in the United States | IJAAR @sli...Innspub Net
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.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Germination percentage and growing behavior of Salix tetrasperma (Willow) as ...Innspub Net
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/
Contributers: Norman Uphoff, CIIFAD, Cornell University, USA
Iswandi Anas, Biotechnology Lab, IPB, Indonesia
O.P. Rupela, former Principal Scientist, ICRISAT, India
A.K. Thakur, Directorate of Water Management, India
T.M. Thiyagarajan, Tamil Nadu Agric. Univ., India
Presented at: Conference of Association of Applied Biologists on Positive Plant-Microbial Interactions
Effect of some abiotic factors on the concentration of β- sitosterol of Prunu...Innspub Net
Prunus africana is a medicinal plant which develops in the mountains of several African countries. β-sitosterol can be used as a marker for the control of the product quality of the aforementioned plant in terms of phytotherapy. Farmers and public authorities do not have information on the influence of altitude and chemical characteristics of soils on the concentration of β- sitosterol of P. africana. To contribute to solve the problem, this research, carried out in Cameroon, aims to appreciate the effect of abiotic factors on the above phenotypic character. In nine composite samples of barks taken at different altitudes, the
concentration of β-sitosterol is appreciated via qualitative analyses by Thin Layer Chromatography, High Performance Liquid Chromatography and quantitative analyses by Gas Chromatography coupled with the Mass Spectrometry. The chemical analyses of soils taken under the stems of the aforementioned trees were made. The statistics were carried out using the SAS software. The concentration of β-sitosterol in each population of P. africana varies from zero to 38.65 μg/ml. There is
variability between the averages of the aforementioned concentration with respect to altitude and chemical elements of the soils but the differences are not significant. The Ascending Hierarchical Clustering distributes populations into three groups. These
tools obtained are indispensable for the ground management, the products exploited from this tree species and the production of seeds for creating forest and agro-forest plantations.
Seasonal growth patterns of Arundo donax L. in the United States | IJAAR @sli...Innspub Net
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.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Genotype by environment interactions and effects on growth and yield of cowpe...Premier Publishers
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.
Seasonal Dynamics of Arbuscular Mycorrhizal Fungi, Glomalin and Soil Properti...ijtsrd
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
Effects of Nitrogen Fertilization and interZiziphus Jujubealleys cropping on ...Agriculture Journal IJOEAR
Abstract— In order to test the effects of intercropping and nitrogen fertilization on blue panic (panicum antidotale) yield, a field experiment was conducted at the Agricultural Research Station of King Abdulaziz University, located at Hada Al-Sham during two consecutive seasons (2013 and 2014). Blue panic was intercropped between interspaces alleys of Ziziphus Jujube under three different levels of nitrogen fertilizer (0 kg N/ha, 200 kg N/ha and 400 kg N/ha in the form of commercial Urea,46%) and three distances from the jujube tree (1m ,2m and 4m). Blue panic fresh and dry forage yield (tons/ha) and quality was assessed during ten cuttings harvests. The results exhibited significant effects of intercropping, nitrogen fertilization and distance from the tree on forage yield and quality. Forage yield across all ten harvests were higher under intercropped plots compared to sole crops and in plots treated with 200 and 400 kg N and 2-meter distance from the trees. Total fresh forage yield /ha/10 cuts of the intercropped blue panic under 400 kg N/ha and 2m distance reached 186 tons/ha/year. Whereas the highest protein content means overall the different cuts was 11.51% in plots fertilized with 400 kg N/ha at 1m distance from the trees. This current study highlights the importance of utilizing jujube alleysto maximize land use value of this widely planted arid land tree.
Keywords— Forage yield, Forage quality, Jujube tree, alley cropping.
Dry Matter Yield and Agronomic Performance of Herbaceous Legumes Intercropped...paperpublications3
Abstract: The study was conducted at the two trial sites (Cheffa and Sirinka) of Sirinka Agricultural Research Center which represents the low and mid altitude agro ecologies of the eastern Amhara region to identify legume species that would have best compatibility with Napier grass and to examine the DM herbage yield of mixed cultures of legumes and Napier grass. Seven adaptable and recommended perennial herbaceous legume species (Desmodium unicinatum, Macrotyloma axillare, Clitoria ternatea, Macroptilium atropurpreum, Stylosanthes guianensis, Stylosanthes hamata and Medicago sativa) were intercropped with recommended Napier grass (Pennisetum purpureum) Acc. No. 14984 for the areas were included in the study. With in the three years experimental periods a total of six and four harvests, with an average harvesting interval of 135 and 206.75 days were obtained at Cheffa and Sirinka trial site, respectively. The agronomic performances of legumes among intercropped treatments and during each harvesting stages, respectively were significantly (P<0.001)><0.01)><0.05)><0.001) in advancement of harvesting stages. As the study result indicates, intercropping Napier grass with herbaceous legumes has significant advantage than growing Napier grass solely in increasing the DM yield harvested. Therefore, among the tested legumes and Napier grass combinations, intercropping Stylosanthes guianensis with Napier grass was found to be the best for its compatibility and higher Napier total (leaf + stem), legume and both (Legume + Napier) DM yields at each (Cheffa and Sirinka) trial site. Therefore, we recommend this combination for future use. However, further studies are needed to evaluate the effect of legume intercropping on herbage quality and soil fertility improvement, and the economic advantage of legumes and Napier intercropping.
Seed management’s influences on nodulation and yield of improved variety of s...Agriculture Journal IJOEAR
Abstract— 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 (farmer’s and researcher’s 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 researchers’ managed seeds showed a significantly higher mean values than farmers’ managed seeds. The pod and total seed weight from researchers’ seeds were 106.26 g and 52.43 g per plant respectively against the farmers’ 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 farmers’ managed seeds could have resulted from factors such poor seed handling or mix up during harvesting or storage, poor quality seed selection for planting.
Formation Patterns of Acridid Communities in Urban Landscapes of TurkmenistanSryahwa Publications
Acridid communities of urbanized landscapes in Turkmenistan are described for the first time. General peculiarities of formation of acridid communities in urban landscapes are studying for the desert zone. The structure of the communities is determined by soil conditions, types of plant cover and the level of anthropogenic impact on the different urban biotopes.
Rice Root physiology work at CIAT: Identification of ideal root system to imp...CIAT
Water and Nitrogen are quantitatively the most essential resources for plant growth. Active root systems that can take up water and nutrients more efficiently are essential for enhancing grain yield. However, it is difficult to find the ideal root system to improve water and Nitrogen uptake because the root growth was sensitive and affected by environment such as drought and nutrient deficiency conditions. However, there were several reported that some constitutive root traits and root controlling genes (QTLs) to improve water and nitrogen uptake (Uga et al. 2013; Arai-Sanoh et al. ; Ogawa et al. 2016) .
Here, we examined with root modified breeding lines using both marker assisted selection and transgenic technology under stress conditions. Using 48 chromosome segment substitution lines (CSSLs) between Curinga; commercial upland rice in Brazil and Oryza rufipogon (IRGC105491); a non-sativa species, we found total 15 QTLs including a QTL for nitrogen-deficiency tolerance in grain yield on chromosomes 1. In addition to QTLs identification, we observed that the dimorphic roots system (that has both shallow and deep roots system) from Oryza rufipogon trait correlated to Nitrogen deficiency tolerance in grain yield under field conditions. Using DEEPER ROOTING 1 (DRO1) inserting transgenic lines, we found higher expression of DRO1 increases the root growth angle, whereby roots grow in a more downward direction. Introducing DRO1 into IR64; a shallow-rooting rice cultivar enabled the resulting line to maintained high yield performance under both water and Nitrogen deficient conditions relative to the recipient cultivar. The result showed us the deeper rooting traits is useful to absorb water and Nitrogen from the deeper layer under both water and nitrogen deficiency conditions.
In the future, these identified root system and genes (QTLs) will shed light on root architecture systems in rice breeding to improve agronomic performance under stress conditions.
Stressful environments such as salinity and drought was assessed on photosynthesis, the most fundamental and intricate physiological process of three oil plants canola (BrassicanapusL.), safflower (Carthamustinctorius L.) and sunflower (Helianthus annusL) grown in different sites in Egypt (Suez road; North Coastal area; El-Kantra East) , is also severely affected in all its phases by such stresses .
Genotype by environment interactions and effects on growth and yield of cowpe...Premier Publishers
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.
Seasonal Dynamics of Arbuscular Mycorrhizal Fungi, Glomalin and Soil Properti...ijtsrd
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
Effects of Nitrogen Fertilization and interZiziphus Jujubealleys cropping on ...Agriculture Journal IJOEAR
Abstract— In order to test the effects of intercropping and nitrogen fertilization on blue panic (panicum antidotale) yield, a field experiment was conducted at the Agricultural Research Station of King Abdulaziz University, located at Hada Al-Sham during two consecutive seasons (2013 and 2014). Blue panic was intercropped between interspaces alleys of Ziziphus Jujube under three different levels of nitrogen fertilizer (0 kg N/ha, 200 kg N/ha and 400 kg N/ha in the form of commercial Urea,46%) and three distances from the jujube tree (1m ,2m and 4m). Blue panic fresh and dry forage yield (tons/ha) and quality was assessed during ten cuttings harvests. The results exhibited significant effects of intercropping, nitrogen fertilization and distance from the tree on forage yield and quality. Forage yield across all ten harvests were higher under intercropped plots compared to sole crops and in plots treated with 200 and 400 kg N and 2-meter distance from the trees. Total fresh forage yield /ha/10 cuts of the intercropped blue panic under 400 kg N/ha and 2m distance reached 186 tons/ha/year. Whereas the highest protein content means overall the different cuts was 11.51% in plots fertilized with 400 kg N/ha at 1m distance from the trees. This current study highlights the importance of utilizing jujube alleysto maximize land use value of this widely planted arid land tree.
Keywords— Forage yield, Forage quality, Jujube tree, alley cropping.
Dry Matter Yield and Agronomic Performance of Herbaceous Legumes Intercropped...paperpublications3
Abstract: The study was conducted at the two trial sites (Cheffa and Sirinka) of Sirinka Agricultural Research Center which represents the low and mid altitude agro ecologies of the eastern Amhara region to identify legume species that would have best compatibility with Napier grass and to examine the DM herbage yield of mixed cultures of legumes and Napier grass. Seven adaptable and recommended perennial herbaceous legume species (Desmodium unicinatum, Macrotyloma axillare, Clitoria ternatea, Macroptilium atropurpreum, Stylosanthes guianensis, Stylosanthes hamata and Medicago sativa) were intercropped with recommended Napier grass (Pennisetum purpureum) Acc. No. 14984 for the areas were included in the study. With in the three years experimental periods a total of six and four harvests, with an average harvesting interval of 135 and 206.75 days were obtained at Cheffa and Sirinka trial site, respectively. The agronomic performances of legumes among intercropped treatments and during each harvesting stages, respectively were significantly (P<0.001)><0.01)><0.05)><0.001) in advancement of harvesting stages. As the study result indicates, intercropping Napier grass with herbaceous legumes has significant advantage than growing Napier grass solely in increasing the DM yield harvested. Therefore, among the tested legumes and Napier grass combinations, intercropping Stylosanthes guianensis with Napier grass was found to be the best for its compatibility and higher Napier total (leaf + stem), legume and both (Legume + Napier) DM yields at each (Cheffa and Sirinka) trial site. Therefore, we recommend this combination for future use. However, further studies are needed to evaluate the effect of legume intercropping on herbage quality and soil fertility improvement, and the economic advantage of legumes and Napier intercropping.
Seed management’s influences on nodulation and yield of improved variety of s...Agriculture Journal IJOEAR
Abstract— 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 (farmer’s and researcher’s 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 researchers’ managed seeds showed a significantly higher mean values than farmers’ managed seeds. The pod and total seed weight from researchers’ seeds were 106.26 g and 52.43 g per plant respectively against the farmers’ 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 farmers’ managed seeds could have resulted from factors such poor seed handling or mix up during harvesting or storage, poor quality seed selection for planting.
Formation Patterns of Acridid Communities in Urban Landscapes of TurkmenistanSryahwa Publications
Acridid communities of urbanized landscapes in Turkmenistan are described for the first time. General peculiarities of formation of acridid communities in urban landscapes are studying for the desert zone. The structure of the communities is determined by soil conditions, types of plant cover and the level of anthropogenic impact on the different urban biotopes.
Rice Root physiology work at CIAT: Identification of ideal root system to imp...CIAT
Water and Nitrogen are quantitatively the most essential resources for plant growth. Active root systems that can take up water and nutrients more efficiently are essential for enhancing grain yield. However, it is difficult to find the ideal root system to improve water and Nitrogen uptake because the root growth was sensitive and affected by environment such as drought and nutrient deficiency conditions. However, there were several reported that some constitutive root traits and root controlling genes (QTLs) to improve water and nitrogen uptake (Uga et al. 2013; Arai-Sanoh et al. ; Ogawa et al. 2016) .
Here, we examined with root modified breeding lines using both marker assisted selection and transgenic technology under stress conditions. Using 48 chromosome segment substitution lines (CSSLs) between Curinga; commercial upland rice in Brazil and Oryza rufipogon (IRGC105491); a non-sativa species, we found total 15 QTLs including a QTL for nitrogen-deficiency tolerance in grain yield on chromosomes 1. In addition to QTLs identification, we observed that the dimorphic roots system (that has both shallow and deep roots system) from Oryza rufipogon trait correlated to Nitrogen deficiency tolerance in grain yield under field conditions. Using DEEPER ROOTING 1 (DRO1) inserting transgenic lines, we found higher expression of DRO1 increases the root growth angle, whereby roots grow in a more downward direction. Introducing DRO1 into IR64; a shallow-rooting rice cultivar enabled the resulting line to maintained high yield performance under both water and Nitrogen deficient conditions relative to the recipient cultivar. The result showed us the deeper rooting traits is useful to absorb water and Nitrogen from the deeper layer under both water and nitrogen deficiency conditions.
In the future, these identified root system and genes (QTLs) will shed light on root architecture systems in rice breeding to improve agronomic performance under stress conditions.
Stressful environments such as salinity and drought was assessed on photosynthesis, the most fundamental and intricate physiological process of three oil plants canola (BrassicanapusL.), safflower (Carthamustinctorius L.) and sunflower (Helianthus annusL) grown in different sites in Egypt (Suez road; North Coastal area; El-Kantra East) , is also severely affected in all its phases by such stresses .
PSFK's Future of Light report is an in-depth survey of the trends shaping light at the intersection of technology, community and sustainability.This survey looks at key trends that focus on how light can support livelihood, improve safety and bring people together, demonstrating the vast potential that light has to positively impact people’s lives across the globe.
The Future Of Light is available free on the iPad, Android devices, and PDF download. The 150+ page document describes 12 trends across 4 broader themes. Each trend is supported by 4 examples, supporting statistics and implications defined by our PSFK Labs team.
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Phasic pattern of dry matter production and accumulation in different parts o...inventionjournals
A field experiment was conducted at farming system research unit of Krishi Vigyan Kendra, Kandhamal as a part of ongoing effort to collect the data in connection to dry matter accumulation and partitioning in three cultivars of cow pea during growth and development stages in two consecutive Summer and Kharif season of the year 2012-13 and 2013-14. The dry matter partitioning had been worked out at 30, 45 and 60 DAS from the stem, leaves and at only 60 DAS from the pods. Results revealed that total dry matter production were higher in the summer season as compare to the rainy season and it increased gradually with the age of the plant. The accumulation of dry matter was more in the pod as compared to leaves and stem. Among the three varieties tested, Maharani showed significant higher accretion of dry matter in the stem (3.38 g plant-1 ) as compared to Lafa (3.28 g plant-1 ) and Utkal Manika (3.13 g plant-1 ) during summer season. In the rainy season Lafa (1.98 g plant-1 ) yielded highest followed by Maharani (1.09 g plant-1 ) and Utkal Manika (0.99 g plant-1 ). Varieties showed the similar trends in the accrual of the dry matter in the leaves and pods, but the amount varies. Maharani accumulate highest during summer season in both leaves and pods 4.60 g plant-1 and 25.26 g plant-1 respectively and lafa performed better in rainy season where accrual of dry matter was 3.01 g plant-1 in the leaves and 19.81 g plant-1 on the pods.
Effect of Transplanting date on the Growth and Yield of Aromatic Rice in Irri...iosrjce
A field experiment was conducted at the Bangladesh Institute of Nuclear Agriculture (BINA) farm
Mymensingh, Bangladesh during the irrigated ecosystem in December, 2009 to May 2010, with a view to study
the performance of aromatic fine rice under different date of transplanting. The experiment was carried out with
four aromatic fine rice (V1= Chinisagar, V2= Chiniatab, V3= Basmati, V4=Awnless Minicat) and three different
date of transplanting (D1=20 January, D2=5 February, D3=20 February). The experiment was laid out in splitplot
design with three replications assigning four varieties in the main plot and the three different transplanting
dates in the sub plot. Aromatic fine rice and dates of transplanting individually showed significant effect on the
agronomic parameters. Among the aromatic fine rice Awnless Minicat gave the highest yield (3.10 t ha-1
) but
that was at per with those of Basmati (1.77 t ha-1
). Transplantation on 20 January gave the highest grain yield
(2.41 t ha-1 ) which was at per with the transplantation on 5 February (1.99 t ha-1 ).The result revealed that 20 January and 5 February produced highest grain yield by all the variety. In later date of transplanting 20 February produced lower grain yield.
Development of drought tolerant maize cultivars is prerequisite to achieving stable grain yield in
drought–prone ecologies of Nigeria’s 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 Nigeria’s savanna ecologies.
Effect of Different Sources of Nutrient on Growth and Yield of Okra (Abelmosc...Agriculture Journal IJOEAR
The experiment was carried out at Nepal Polytechnic Institute field, Bharatpur, Chitwan, Nepal to study the effect of different nutrient sources on growth and yield of okra (Abelmoschus esculentus L Monech). Five different treatments; poultry manure, FYM, goat manure, chemical (as per N equivalent) and no fertilizer (control) were replicated four times. The experiment was arranged in Randomize Complete Block Design (RCBD). The okra variety ArkaAnamika was used for experiment. The data were collected on the growth and yield parameters including plant height (cm), canopy (cm), numbers of leaves per plant, numbers of branches per plant, fruit length, diameter and yield. Results indicated that different nutrient sources had significant (P<0.05) affected on plant height, canopy, leaf number, branches and also in yield parameters. Based on the findings of the experiments, it can be concluded that application of poultry manure significantly increased the growth and yield performances on Abelmoschus esculentus L. Monech (okra) compared to other types of fertilizers. As the study reflected the use of no fertilizer results in the lowest vegetative growth and yield performances which indicates to use some nutrient sources for better growth and production of okra.
Effects of Water Deficiency on the Physiology and Yield of Three Maize GenotypesAgriculture Journal IJOEAR
Three maize genotypes research experiment was carried out in the experimental farm of University of Debrecen, Hungary. The genotypes were subjected to two different treatments, (irrigated and non-irrigated) where the irrigated was the control experiment. Physiological parameters (SPAD, LAI, HEIGHT) and grain yield (kg ha-1) were measured and statistically computed. From our results, SPAD, LAI and HEIGHT values were significantly affected by water stress in the three studied genotypes. Grain yield was reduced in two of the studied genotypes (S.Y Zephir and S.Y Chorintos). But no significant difference was notice in the KWS 4484 cultivar. LAI was not affected in the second measurement in the S.Y Chorintos genotype and, plant height did not record any difference in the first measurement in the KWS 4484 cultivar. Our results suggest second experiment to specifically look at the critical stage in the genotypes growth where water stress has the severe effect on the studied genotypes.
Morphological and physiological attributes associated to drought tolerance of...Innspub Net
The experiment was conducted to assess the differential morpho-physiological response to stimulated water deficit and to determine the relationship between some of these morphological and physiological traits and yield components of eighteen durum wheat genotypes grown in pots under lathhouse condition. Water deficit significantly affected gas exchange and chlorophyll fluorescence parameters. It reduced the net photosynthesis rate (Pn), transpiration rate (E) and stomatal conductance (gs) measured both at anthesis and grain-filling stages. Similarly, the value of initial fluorescence (Fo) was increased while variable fluorescence (Fv), maximum fluorescence (Fm) and optimum quantum yield fluorescence (Fv/Fm) were decreased under water deficit. RWC of the leaves was decreased by 36.7% while SLA increased by 12.6% due to moisture stress relative to the well-watered control. No significant correlations were found between chlorophyll fluorescence parameters and grain yield under water deficit condition. Similarly, no significant correlations were found between leaf gas exchange parameters and grain yield. On the other hand, peduncle length and excursion were positively correlated with grain yield while negatively correlated with drought susceptibility index under water deficit condition. Leaf posture and rolling had also a profound effect on grain yield and other attributes. Erect-leaved genotypes had more grain yield, HI, kernel numbers per spikelet and grain-filling rate but had lower kernel weight than droopy leaved. Similarly, genotypes exhibited strong leaf rolling under water deficit condition had more grain yield, kernel numbers per spike and water use efficiency. The genetic variability found for leaf posture, leaf rolling, peduncle length and excursion among the Ethiopian durum wheat genotypes suggests the opportunity for selection superior and adapted genotype in water-limited environments. These can be achieved by integrating these morphological traits as indirect selection in conjunction with other yield components. Get the full articles at: http://www.innspub.net/volume-1-number-2-april-2011-2/
Ecophysiological Yield Components In Wheat Cultivars Under Variable Phosphoru...Agriculture Journal IJOEAR
Abstract— 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.
Alinteri Journal of Agriculture Sciences is being published online biannually as of 2007. Alinteri Journal of Agriculture Sciences aims to create an environment for researchers to introduce, share, read, and discuss recent scientific progress. The journal is an open access, international, double-blind peer-reviewed journal publishing research articles, Invited reviews, short communications, and letters to the Editor in the fields of agriculture, fisheries, veterinary, biology, and closely related disciplines. We adopt the policy of providing open access to readers who may be interested in recent developments.
Evaluation of viable selection criteria at the seedling stage in corn genotyp...Innspub Net
Drought is the only factor which causes a more drastic effect on crop plant. Corn is a drought-sensitive crop their yield is influenced at every single phase of growth and development by limited water availability. Corn. A total of 90 accessions were screened and evaluated at different water levels 100% (T1), 40% (T2) and 30% (T3) of field capacity (FC). Evaluation of corn genotypes was done against six seedling parameters (root length, shoot length, fresh root weight, fresh shoot weight, dry root weight and dry shoot weight). The analysis of variance indicated that all the traits under all water levels revealed significantly and the principal component analysis depicted diverse results for different treatments. The results showed that the genotypes Lala Musa, Akbar, Sahiwal-2002, Sultan, Pearl, 15005,15077,14972,15110 under 100% FC level performed well and genotypes 14933,15023,14968,15055, 15005, MMRI yellow, Lala Musa, Pearl, Akbar, Akhgoti, 15067 and Sultan under 40% FC and the genotypes Desi Fsd, 15075, Lala Musa, 14930, 14976, 15132, 15048, Sultan and 15005 performed best in 30% FC. Some corn genotypes Akhgoti, Lala Musa, Sultan, and 15005 performed better under all three water levels. The information on seedling parameters is best suited to screen viable genotypes for baseline information for on-ward corn breeding and research programs on water stress tolerance.
Evaluating the performance of improved sweet potato (Ipomoea batatas L. Lam) ...Innspub Net
Field trials were conducted in the 2014 rainy season at the Teaching and Research Farm of Bayero University, Kano (11°58’N and 8°25’E) and Agricultural Research Station Farm, Minjibir (12°11’N and 8°32’E). The objective of the study wasto evaluate the performance of improved sweetpotato lines with a view to identify those that may be adaptable with high yielding potential in the study area.The treatments consisted of 16 sweetpotato advanced lines: Centennial, AYT/08/055, TIS8164, TIS87/0087, NRSP12/097, UMUSPO/2, UMOSPO/1, SOLOMON-1, EA/11/022, EA/11/025, EA/11/003, UM/11/015, NRSP/12/095, UM/11/001, UM/11/022, and a local check
(Kantayiidda). These were laid out in a Randomized complete block design with 3 replications. Significant differences were observed in number of roots per plant, number of marketable roots, number of pencil roots, flesh colour, root shape and root yield. Kantayiidda produced significantly (p<0.05) higher root yield (10315kg/Ha) than all other lines. Solomon-1, Umuspo/1, EA/11/022, UM/11/001 and TIS87/0087 were found to be promising among the advanced lines evaluated; thus could relatively compete with Kantayiidda local for adaptation and high root yield in the study area. Get full articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Natural farming @ Dr. Siddhartha S. Jena.pptxsidjena70
A brief about organic farming/ Natural farming/ Zero budget natural farming/ Subash Palekar Natural farming which keeps us and environment safe and healthy. Next gen Agricultural practices of chemical free farming.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
Effects of Light Intensity and Quality on Physiological Changes in Winter Rice (Oryza Sativa L.)
1. International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-3, March- 2016]
Page | 65
Effects of Light Intensity and Quality on Physiological Changes
in Winter Rice (Oryza Sativa L.)
Basanta Barmudoi1
, Bhagawan Bharali2
1, 2
Department of Crop Physiology, Assam Agricultural University, Jorhat
Abstract— An investigation into the effects of low light (meanPPFD169-493Ms-1
m-1
), red light (meanPPFD657-
843Ms-1
m-1
) and normal light (meanPPFD1061-1260Ms-1
m-1
) on physiological changes including yield attributes,
nutritional status at Panicle initiation (PI), flowering and harvest stages in winter rice (genotype: Monoharsali) was carried
out from 40 days after transplanting (DAT) to crop maturity under both pot and field conditions. There was reduction in
available PPFD at flowering as compared to PI stage of the crop. The genotype exhibited significantly higher total dry
matter (TDM) and lower leaf area index (LAI) values at normal light or red light than at reduced light situation. The bio-
economical yield and harvest index (HI) under normal light exceeded those at low light regime. The yield attributes viz.,
number of panicles, number of field grains per panicle, 1000 grain weight (test weight), high density (HD) grains, potential
1000 grain weight and sink capacity were superior at normal or red light to low light condition. Higher the total
carbohydrate contents in grains, higher were the sink capacity with the normal /red light illuminations at harvest stage. At PI
stage, leaf nitrogen content was reduced by low light, but it increased at flowering stage significantly. Grain protein
contents, under normal/red light exceeded its value at low light treatment. A positive correlation of most of the yield
attributes with grain yield at normal/red light, and a negative correlation of these parameters were found at low light
conditions.
Keywords— low light, red light, white light, PPFD, HI, test weight, HD grains, Sink capacity.
I. INTRODUCTION
Rice (Oryza sativa L.) grown in winter season in tropical and subtropical regions are influenced adversely by the climatic
conditions, which is characterized by overcast sky posing low sunshine hours during the vegetative to reproductive growth
stages of the crop. Rice plant requires about 1500 bright sunshine (BSS) hours for the period from transplanting to maturity.
Instead, prevalence of only about 800-900 BSS hours during August to December in places like Northeastern region of India
hampers the physiological efficiencies, and ultimately the productivity of winter rice crop (Bharali et al., 1994). It’s because,
solar radiation in tropics is one of the major climatic factors limiting grain yield in rice (Vergara et al., 1976).
Apart from light intensity, an illumination condition is determinant for proper growth and development of plant, which
ensures interactions of all photoreactions (Voskresenenskya, 1979). Many vital biosynthetic processes of plant can be
regulated by simple alteration of light quality. Accumulation of carbohydrate, particularly starch is a notable metabolic
feature of plants photosynthesizing under red light during a long period. In plants under the influence of blue light, the
carbon is preferentially utilized for biosynthesis of proteins (Pierson and Lowallik, 1964). The peculiarities in metabolism
due to effects of light quality are accompanied by changes in chloroplast organization. The plants under red light form lesser
active chloroplast than plants under blue light. Moreover, the plants photosynthesizing under red light have limited CO2
exchange, week photophosphorylation and low activity of electron transport from water (Voskresenskaya, 1972). Low light
at PI and flowering stages of crop causes physiological aberrations in rice including nutritional imbalance (Bharali et al.,
1993). The present study attempted to compare the physiological performance of winter rice crop modulated by low light and
red light in comparison to normal light in field and pot culture conditions.
II. MATERIALS AND METHODS
A field experiment laid in RBD and another pot culture experiment framed in CRD, were conducted on winter rice (Variety
Manoharsali), to study the impacts of low light cum red light and normal sunlight light on physiological changes of the crop.
2. International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-3, March- 2016]
Page | 66
In field, 30 days old seedlings (n=2) were transplanted at 10cm (Plant x Plant) and 20cm (Row x Row) apart onto the well
puddle and leveled plots. Fertilizers @40:20:20 NPK per hectare were applied as Urea, Single super phosphate (SSP) and
Muriate of potash (MoP). In case of pot culture, rice seedlings (n=1) of 30 days old, was transplanted to the earthen pots
(diameter: 32cm). A mixture of sandy loamy soil with FYM @4:1 was used to fill in one pot (capacity: 6.5 Kg soil). The pot
mixture also contained the NPK fertilizers @40:20:20. In both the experiments, half of N and entire doses of P and K were
applied as basal, and the remaining half of the N was top-dressed at 30 days after transplanting (DAT). In the field plots and
laboratory pots, constant water supply (2-3cm) was ensured from transplanting till seven days before harvesting.
Normal sunlight was reduced to 50% (Low light) using standard hessian cloth fitted in a bamboo frame at one meter above
the ground, at 40 DAT till maturity of the crop. Each plant was wrapped with two layers of red cellophane papers loosely
allowing the gaseous exchange, which permitted only the red spectrum of visible light with emission maximum 650nm
(Sharma et.al., 1976). Light intensity below and above the crop canopy was measured using a Lux Meter (York Scientific
Industries, YORCO) at PI and flowering stages of the crop. The light intensity readings (Lux) were converted into ES-1
m-2
(Dhopte et al., 1989; Clayton, R. K. (1970)). The total rainfall and BSS during the crop season (July to December) were
927.4mm and 1060.7 hours respectively (Meteorological Observatory, AAU, Jorhat).
III. PHYSIOLOGICAL PARAMETERS
Leaf area (L x B x constant factor) was measured at PI and flowering stages (Yoshida et al., 1976) of crop growth, where L:
maximum length, B: Average breath of leaf. Constant factor for PI: 0.69 & Flowering stage: 0.75. LAI was calculated as the
ratio of total leaf area to the ground area covered by the plant canopy. The second leaf from the top was sampled, oven dried
at 60o
C to a constant weight and recorded as specific leaf weight (SLW). Panicle length measured from the nodal base to the
tip of the panicle.
The above ground parts of five observational plants in each plot or the whole plant in each pot, were oven dried at 60o
C to a
constant weight. Dry matter /m2
(average dry weight x total no. of plants/m2
) was converted into kg/ha at PI and flowering
stages. At harvest, plants/m2
area from each plot were threshed to separate grains from straw and after proper drying in
sunshine, biological (straw + grains) and economic yield were expressed as q/ha. In case of pot experiment, these parameters
were recorded as g/pot. Harvest index (HI) were calculated by proportioning biological yield to grain yield. 1000 seeds were
randomly collected from each seed lot of individually harvested plot and pot, weighed in electrical balance after proper
drying (14% moisture) and recorded as test weight. The per cent well filled grains, high density (HD) grains were determined
using 1.20 specific gravity salt solution and 50g seed from each treatment in the experiments (Nichiporovich, 1967). Sink
capacity (number of panicles/m2
x spikelet/panicle x individual grain weight) was calculated as suggested by Venkateswrulu
and Visperas (1987).
IV. CHEMICAL ANALYSIS
In field and pot experiments, five randomly selected leaves were ground in electrical grinder after drying in oven at 60o
C into
a constant weight. Powdered materials were sieved and stored in desiccators. Nitrogen estimation in leaf samples was done
by Micro-Kjeldhal method (A.O.A.C. 1965) at PI and flowering stages. Nitrogen estimated in grains on dry weight basis
following the same procedure was converted into crude protein multiplying it by a factor of 5.95 (Juliano, 1972). Total
carbohydrate content was determined in leaf and dehusked grain (Daniel, 1982; Yoshida et. al. 1976) too.
V. STATISTICAL ANALYSIS
Data for each character was analyzed by Fisher’s method of analysis of variance. Least significance difference (LSD)
between a pair of treatment means at P<0.05 was used for determination of the significance difference between two treatment
means. The relationship of economic yield with yield attributing parameters under different light regimes was determined
from simple correlation studies.
3. International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-3, March- 2016]
Page | 67
VI. RESULTS
Data on light intensity under different light regimes at PI and flowering stages of rice crop are portrayed in Table 1 (a & b).
In the field experiment, light intensity was lesser than at flowering stage. There was always higher interception of light above
the canopy than below the canopy level of the crop irrespective of growth stages. In field, the highest mean PPFDs was found
in normal light and the lowest was in low light treatment at both PI and flowering stages respectively. The similar trend of
available PPFD was also observed in the pot experiment.
TABLE1(A)
VARIATION OF LIGHT INTENSITY (E s-1
m-1
) AT PI AND FLOWERING STAGES OF RICE CROP
Field experiment
PI stage Flowering stage
Light regimes
Below
canopy
Above
canopy
Mean
Below
canopy
Above
canopy
Mean
Normal sunlight (400-
700nm):NL
657.271 1725.472 1224.768 609.178 1513.326 1061.252
Red light (600-
700nm):RL
378.330 1272.861 823.990 339.857 971.479 657.271
Low light (50% of NL):
LL
227.640 955.448 583.528 169.929 766.282 468.105
TABLE1(B)
VARIATION OF LIGHT INTENSITY (E s-1
m-1
) AT PI AND FLOWERING STAGES OF RICE CROP
Pot culture experiment
PI stage Flowering stage
Light regimes
Below
canopy
Above
canopy
Mean
Below
canopy
Above
canopy
Mean
Normal sunlight (400-
700nm):NL
663.683 1859.596 1260.037 631.621 1538.976 1083.696
Red light (600-
700nm):RL
407.187 1282.48 843.231 365.507 981.097 673.302
Low light (50% of
NL):LL
230.846 971.479 602.766 198.784 785.519 493.755
In the field trial, total dry matter production (TDMP) varied significantly in different light regimes (Table 2). At PI stage the
highest TDMP (9244kgha-1
) was found under normal light, whereas, it was the lowest (8274kgha-1
) under low light
condition. At flowering stage, the similar trend was found in respect of TDMP under different light regimes. In pot culture
experiment, too, the TDMP at harvest stage was alike (NL:52.58>RL50.62>LL46.72) with the field observation.
4. International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-3, March- 2016]
Page | 68
TABLE 2
VARIATION OF TOTAL DRY MATTER PRODUCTION (TDMP) AT PI, FLOWERING AND HARVEST STAGES OF
RICE CROP
Field experiment Pot experiment
PI stage Flowering stage Harvest stage
Light regimes Kgha-1
x 102
Kgha-1
x 102
g pot-1
Normal white light (400-700nm) 92.44a
140.56a
52.58a
Red light (600-700nm) 87.30a
135.64a
50.62a
Low light (50% of NL) 82.74b
110.58b
46.72b
SEDiff. (±) 3.091 2.751 1.429
LSD (0.05) 6.894 5.727 3.029
Values with similar superscript letters within a column are not significantly different at P(0.05)
Data on field experiment (Table 3) indicates that leaf area index (LAI) differed significantly amongst the three light
treatments at PI stage, but the difference was not significant at flowering stage of the crop. At PI stage, LAI was the highest
(7.16) under low light and the lowest (5.13) was recorded in plants exposed to normal light condition. At flowering stage, the
highest (6.10) and the lowest (5.85) LAI were found under low and normal light regimes respectively. The results of the pot
experiment (PI: LL 7.12>RL5.85>NL5.11 & FS:LL6.0>RL5.95>NL5.25) similar to the field experiment also.
TABLE 3
VARIATION OF LEAF AREA INDEX (LAI) AT PI AND FLOWERING STAGES OF RICE CROP
Field experiment Pot experiment
PI stage Flowering stage PI stage Flowering
stageLight regimes
Normal white light (400-700nm) 5.13a
5.85a
5.11a
5.25a
Red light (600-700nm) 5.90b
6.08a
5.85b
5.95a
Low light (50% of NL) 7.16b
6.10a
7.12c
6.00a
SEDiff. (±) 0.078 0.226 0.0532 0.556
LSD (0.05) 0.174 n.s. 0.167 n.s.
n.s.: non significant
Values with similar superscript letters within a column are not significantly different at P(0.05)Total carbohydrate contents (TCC) in leaf and grain are displayed in Table 4. In field, TCC in leaf varied significantly both at
PI and flowering stages of growth due to the treatments of different lights. At PI stage, plants under normal light produced
the highest (5%), and the low light treated plants had the lowest (3.87%) TCC in leaf. At flowering stage, the highest (8.10%)
and the lowest (5.75%) values of TCC in leaf were recorded in plants under normal and low light conditions respectively.
Moreover, the TCC in leaf under normal light and red light conditions were equal at both PI and flowering stages
statistically.
TABLE 4
VARIATION IN TOTAL CARBOHYDRATE CONTENT (TCC) AT PI AND FLOWERING STAGES OF RICE CROP
Field experiment Pot experiment
TCC in leaf
(% d.w.)
TCC in grains
(% d.w.)
TCC in leaf
(% d.w.)
TCC in grains
(% d.w.)
Light regimes PI stage Flowering stage Harvest stage PI stage Flowering stage Harvest stage
Normal white light
(400-700nm)
5.00a
8.10a
64.14a
5.01a
8.00a
64.12a
Red light (600-700nm) 4.94a
7.84a
63.26a
4.96a
7.86a
63.27a
Low light (50% of NL) 3.87b
5.75b
60.07b
3.90b
5.54b
59.12b
SEDiff. (±) 0.1759 0.1759 0.4605 0.1827 0.0783 0.391
LSD (0.05) 0.392 0.392 1.050 0.387 0.166 1.553
n.s.: non significant, d.w.: dry weight.Values with similar superscript letters within a column are not significantly different at P(0.05)
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In field, TCC in grain at harvest differed significantly between red light and low light as well as normal light and low light
conditions. Of course, under low light, plants produced the highest (64.14%) TCC in grain. The lowest (60.07%) TCC in
grain was found under low light condition. A similar trend was also found in respect of TCC in leaf
(NL:5.01%>RL:4.96>LL3.90) and grain (NL:64.12>RL:63.27>LL:59.12) in case of pot experiment.
Nitrogen contents in leaf at PI and flowering stages differed significantly amongst low light and red light or normal light both
in filed and pot culture conditions (Table 5). In field, at PI stage, the leaf N content was maximum under normal light
(1.89%) and the same was minimum with low light. In contrast, leaf N content increased under low light (1.87%) as
compared to normal or red light conditions at flowering stage. There was no significant difference in grain protein content
among the light regimes. The similar trend in case of leaf nitrogen at PI (NL:1.88% R>RL:1.87>LL1.41%), at flowering
(LL:1.86>RL:1.42:>NL:1.35) and grain protein contents were recorded in pot culture .
TABLE 5
VARIATION IN LEAF N AND GRAIN PROTEIN CONTENTS AT DIFFERENT GROWTH STAGES OF RICE CROP
Field experiment Pot experiment
Leaf N
(% d.w.)
Grain protein
(% d.w.)
Leaf N
(% d.w.)
Grain protein
(% d.w.)
Light regimes PI stage Flowering stage Harvest stage PI stage Flowering stage Harvest stage
Normal white light
(400-700nm)
1.89a
1.36a
9.35a
1.88a
1.35a
9.30a
Red light (600-700nm) 1.88a
1.43a
9.30a
1.87a
1.42a
9.25a
Low light (50% of NL) 1.42b
1.87b
9.10a
1.41b
1.86b
9.12a
SEDiff. (±) 0.0513 0.0056 0.0056 0.0361 0.0445 0.024
LSD (0.05) 0.114 n.s. 0.077 0.077 0.094 n.s.
n.s.: non significant, d.w.: dry weight Values with similar superscript letters within a column are not significantly different at P(0.05)
Data displayed in Table 6 showed significant differences among the treatment means in respect of number of spikelets
/panicle and well filled grains/panicle and sink capacity. Normal light produced the highest spikelet numbers (159.27&18.66)
and well filled grains (123.08 & 123.58) under field and pot culture conditions respectively. The lower of these two
parameters viz., (119.69 & 106.69) and (139.12& 108.19) were recorded in case of low light conditions of field and pot
experiments respectively. The highest sink capacity was found with normal light (1045 & 1722.01gm-2
), and the lowest of it
was in low light (643.06& 1085gm-2
) in field and pot experiments respectively.
TABLE 6
VARIATION IN NUMBER OF SPIKELETS, WELL FILLED GRAINS AND SINK CAPACITY OF RICE CROP
Field experiment Pot experiment
No. of
spikelets
/panicle
No. of well
filled
grains/panicle
Sink
capacity
(gm-2
)
No. of
spikelets
/panicle
No. of well
filled
grains/panicle
Sink
capacity
(gm-2
)
Light regimes
Normal white light
(400-700nm)
159.27a
123.08a
1045.36a
159.42a
123.58a
1722.01a
Red light (600-700nm) 156.07a
120.16a
1011.12a
156.38a
119.75a
1656.80a
Low light (50% of NL) 119.69b
106.69b
643.06b
139.12b
108.19b
1085.42b
SEDiff. (±) 1.610 1.603 138.033 7.352 3.641 82.562
LSD (0.05) 3.581 3.570 307.53 15.586 7.718 175.03
n.s.: non significant, d.w.: dry weight Values with similar superscript letter within a column are not significantly different at P(0.05)
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Data executed in Table 7 showed that there were significant differences among the treatment means of 1000 grain weight
(test weight), proportion of HD grains and potential 1000 grain weight. Low light produced the lowest test weight (20.81g);
HD grains (50.49%) and potential 1000 grain weight (25.44%). However, the highest 1000 grain weight (24.92g), HD grains
(61.33%) and potential 1000grain weight (28.54g) were recorded under normal light condition. All the three parameters
possessed the parallel values under normal light and red light conditions. The results obtained in the pot experiment
confirmed the validity of these data also.
TABLE 7
VARIATION IN 1000 GRAIN WEIGHT, HD GRAINS AND POTENTIAL 1000 GRAIN OF RICE CROP
Field experiment Pot experiment
1000 grain
weight (g)
HD grains
(%)
Potential 1000
grain weight
(g)
1000 grain
weight (g)
HD grains
(%)
Potential
1000
grain
weight (g)
Light regimes
Normal white light
(400-700nm)
24.92a
61.33a
28.54a
24.52a
60.47a
28.21a
Red light (600-700nm) 24.31a
60.21a
28.05a
24.50a
58.98a
27.13a
Low light (50% of NL) 20.81b
50.49b
25.44b
20.25b
49.33b
26.25b
SEDiff. (±) 1.325 1.934 0.7683 1.243 1.982 0.648
LSD (0.05) 3.070 4.301 1.711 2.982 4.201 1.373
n.s.: non significant, d.w.: dry weight, Values with similar superscript letters within a column are not significantly different at P(0.05)
There was compelling evidence on the significant impacts of light treatments on economic yield, biological yield and harvest
index (Table 8). Under normal light, they were recorded as the highest with the values 36.77qha-1
, 88.74qha-1
and 41.03%
respectively. The values of these parameters under normal light and red light were similar. However, plants under low light
produced the lowest economic yield (23.50qha-1
), biological yield (63.0qha-1
) and HI (36.96%). The findings of the pot
culture stood parallels with the trend in data from the field experiment.
TABLE 8
VARIATION IN ECONOMIC YIELD, BIOLOGICAL YIELD AND HARVEST INDEX OF RICE CROP
Field experiment Pot experiment
Economic
yield (qha-1
)
Biological
yield (qha-1
)
Harvest
index (%)
Economic
yield (qha-1
)
Biological
yield (qha-1
)
Harvest
index (%)
Light regimes
Normal white light
(400-700nm)
36.37a
88.74a
41.03a
34.16a
70.16a
48.68a
Red light (600-700nm) 33.11a
80.90a
40.31a
33.08a
69.33a
47.76a
Low light (50% of NL) 23.50b
63.0b
36.96b
30.18b
66.45b
45.43b
SEDiff. (±) 4.178 8.173 1.536 0.645 1.181 1.037
LSD (0.05) 9.30 18.209 3.420 1.372 2.503 2.199
n.s.: non significant, d.w.: dry weight, Values with similar superscript letters within a column are not significantly different at P(0.05)
In field, the correlations studies expressed in Table 9(a) indicate that panicle length (0.217), panicle number (0.191), spikelet
per panicle (0.812), well field grains per panicle (0.189), HD grain weight (0.336), TDMP (0.468) and HI (0.141) were
positively correlated with grain yield. All the parameters showed a positive correlation with economic yield under red light
condition. Under low light condition, HI (0.991*) had a significant positive correlation with grain yield. Panicle length
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(0.466), spikelet per panicle (0.377), well filled grain per panicle (0.478), HD grain weight (0.255) and TDMP (0.412) had
positive correlation with grain yield. Low light maintained negative correlation of Panicle/m2
area (-0.314) with grain yield.
The correlation studies from the pot culture data (Table 9b) exhibited that under normal light condition, number of panicle
per pot (0.892*) and number of well filled grains per panicle (0.836*) had significant positive correlations with economic
yield. Spikelet number per panicle (0.596), HD grain weight (0.644) and HI (0.778) were also positively correlated with
grain yield. Under red light condition, panicle length (0.890*) and HD grain weight (0.816*) only maintained significant
positive relationship with economic yield. Panicle number per pot (0.610), number of spikelet per panicle (0.391), number of
well filled grains per panicle (0.293), leaf area (0.157), TDMP (0.385) and HI (0.752) were positively correlated with grain
yield. Under shade condition, panicle length (0.360), well filled grains per panicle (0.563), HD grain weight (0.393) and HI
(0.641) were positively correlated with economic yield. Panicle number per pot, spikelet per panicle, and TDMP, were
negatively correlated with grain yield.
TABLE 9
RELATIONSHIP OF GRAIN YIELD WITH YIELD ATTRIBUTING PARAMETERS UNDER DIFFERENT LIGHT
REGIMES
(a)
In Field
Panicle
length
Panicle/m2
Spikelet/panicle Well filled
grains/Panicle
HD grain
weight
TDMP HI
NL 0.217 0.191 0.182 0.109 0.366 0.468 0.141
RL 0.700 0.122 0.521 0.169 0.086 0.468 0.272
LL 0.466 -0.300 0.377 0.478 0.255 0.412 0.991*
(b)
In Pot
culture
NL 0.588 0.892* 0.596 0.863* 0.644 0.760 0.778
RL 0.890* 0.610 0.391 0.293 0.816* 0.385 0.752
LL 0.360 -0.179 -0.363 0.563 0.393 0.248 0.641
NL: Normal white light, RL: Red light, LL: Low light (50% of NL), * Significance at P(0.05).
VII. DISCUSSION
In the present study, several physiological parameters (e.g. TDMP, TCC, N contents, yield and yield attributes) except LAI
were reduced markedly by low light in comparison to red light and normal light both in filed and pot culture conditions. The
effects of the light regimes have been studied at the canopy level of the crop. Light intensity declined gradually ‘above and
below canopy’ from panicle to flowering stages under normal white light, red light and low light conditions. Hoover (1934)
stated utilization of incident solar radiation by crops of different structures. The rate of photosynthesis and light intensity has
a linear relationship, photosynthesis increases with increase in light intensity and declines at light saturation point. In
photosynthesis, the only radiation absorbed by chlorophyll is limited to wave band 400-700 nm (PAR). In our field and pot
culture studies, light intensity at canopy level was in conformity within the normal ranges (full sunlight: 2500-4500 Em-2
and cloudy: 250-1000Em-2
), which prevail in Northeast India. The percentage utilization of energy in photosynthesis is
maximal (2.5-3%) at about 100-200 K Cal m-2
hr-1
. This relationship suggests that L (Leaf area index) should be sufficiently
high to absorb as much as possible of the incoming solar energy. The condition involves some mutual shading of leaves, but
still higher L with more severe mutual shading has adverse effects.
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FIG.1 PER CENT REDUCTION IN TOTAL DRY MATTER PRODUCTION (TDMP) IN LIGHT REGIMES IN
COMPARISON TO NORMAL WHITE LIGHT
In general there was reduction of total dry matter production of the crop at PI, flowering and harvest stages under red light
(3-5%) and low light (10-21%) as compared to normal white light (Fig.1). However, the reduction is more with low light
than red light. This is in agreement with Nayak and Murty, 1980. Dry matter production irrespective of light regimes
especially at flowering stage of the crop is of paramount importance for checking spikelet sterility and proper grain filling
linked to yield potential (Sahu,1984). However, a wide gap between spikelet number and number of filled grains is apparent
during the wet season due to the poor supply of carbohydrates from the source leaf, and it is associated with high spikelet
sterility (Venkateswrulu, 1977).
LAI increased with red light (PI:15%; Flowering:4%) and low light (PI:39%; Flowering:14%) both in field and pot culture
conditions in comparison to normal white light. LAI at PI stage under shade condition was more than normal light condition,
which was superior significantly to flowering stage. Further, LAI declined with increase in the age of the crop growth, which
is clear from the present finding (Fig. 2). Tanaka et al., (1964) also opined that LAI increases according to the compound
interest law, reaches its highest value a little before heading and decreases thereafter due to withering of leaves. The
influence of solar radiation on LAI may be explained as an adaptation of the plants to develop thin large leaves under weak
light. However, increase in LAI is also limited by low a level of solar radiation.
FIG.2 PER CENT INCREASE IN LAI IN RED AND LOWLIGHT IN COMPARISON TO NORMAL WHITE LIGHT
Low light reduced total carbohydrate contents in leaf (22-30%) and grain (6-8%) significantly, and merely by red light
invariably at PI and flowering stages of the crop in comparison to normal white light (Fig.3). The reduction in TCC in leaf by
reduced light is due to impairment of dry matter production at PI, and even more reduction of it after flowering for
partitioning into the developing grains at harvest (Janardhan et al., 1980).
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FIG. 3 PER CENT DECREASE IN TCC UNDER RED AND LOW LIGHT IN COMPARISON TO NORMAL WHITE LIGHT
The partitioning of TDMP to panicle is also poor due to weak supply of carbohydrate under low light regimes, which
increases spikelet sterility and lower harvest index (Palit et al., 1976; Sahu et al., 1980). Reddy et al (1987) suggested that
low light intensity during crop growth helps in accumulation of fructose 2, 6 bisphosphate which modulate the key enzymes
of sucrose biosynthesis than regulating carbon flow under conditions of limited photosynthesis. Murty et al. (1976) amply
demonstrated that the movement of photosynthates to aerial parts is enhanced under lower light intensity. But, the available
photoassimilates are low due to impaired photosynthesis under reduced light intensity, and hence varieties efficient in this
trait under low light conditions need to be identified.
FIG.4 PER CENT CHANGES IN NITROGEN CONTENT IN RED AND LOW LIGHT IN COMPARISON TO NORMAL
WHITE LIGHT
At PI stage, N content decreased in low light (24-25%) significantly whereas, at flowering stage, N increased in Low light
(38%) and Red light (4-5%) in both the field and pot experiments. Sahu and Murty (1976) also opined that nitrogen uptake
at flowering is relatively high in wet season and is reduced only after flowering. So, plants growing under lower light always
show higher nitrogen content in shoot and panicle at flowering (Fig. 4). It has consequence on the high sterility of grains in
plants under lower light regimes. Greater accumulation of Nitrogen, especially soluble N occurs in panicle during anthesis,
and at a juvenile stage of grain development. Low light intensity influences the amount of nitrogen utilized for grain
production (Pandaraju et al 1976).
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Decreases in number of spikelet/panicle (12-24%), well filled grains/panicle (12-13%), sink capacity (36-38%) were
found under low light in comparison to normal white light both in filed and pot culture conditions (Fig. 5). Reduced light
during reproductive and ripening stages is much more harmful in economic point of view. As the flowering in the shortest
and medium duration rice varieties synchronize with lower light intensity, it has impacts on yield and yield attributes. So,
reduction in grains per panicle, increases in spikelet sterility, lower sink capacity and lower grain yield are observed in rice
under lower light levels (Murti and Rao, 1982).
FIG.5 PER CENT REDUCTION IN YIELD ATTRIBUTES IN RED AND LOW LIGHT IN COMPARISON TO NORMAL
LIGHT
In the present study there were decreases in 1000grain weight (16-17%), HD grains ( 17-18%), potential 1000grain weight
(6-10%) under low light in comparison to normal white light conditions irrespective of field and pot culture. Stansel et al.
(1965) stated that low light intensity increases sterility and reduces yield. Spikelet sterility is one of the major constraints in
rice productivity as it influences directly the grain yield by limiting the number of filled grains per unit area (Vergara et al.,
1966). The lower grain yield during wet season is mostly due to high sterility of spikelets, and consequent reduction in the
number of filled grains per panicle per unit ground area (Yoshida and Parao, 1976). High sterility during the cloudy monsoon
season is attributed to the prevalent low solar radiation (Venkateswrulu, 1976).
Rao et al. (1986) pointed that the partially filled grains appear in declining order with the initiation of grain-filling, and the
number of grain increasers linearly with time. Venkateswarlu et al. (1977) opined that the grain yield can be enhanced by
increasing the number of high density grains in rice. The percentage contribution of HD grains to total grain emerges as a
major determinant of grain yield. Thus, cultivars possessing a higher production of HD grains would be advantageous even
under low PAR.
Economic yield (12-35%), Biological yield (5-29%) and Harvest Index (7-10%) decreased under low light in comparison to
normal light from either pot and field experiments. All these yield parameters in red light did not differ significantly from
those in normal white light. Janardhan and Murty (1980) reported that grain yield was reduced under low light due to low
grain number per panicle and grain size. Better mobilization capacity of the ‘Indicas’, particularly the late maturity types
recorded high yield than the semi dwarf under low light. Low light intensity during the crop growth period, especially at
reproductive stage reduces the yield of rice (Yoshida, 1972). However, in late maturing high yielding ‘Indica’ rice,
insufficient solar radiation up to flowering causes reduction in yield due to severe damage of tillers ultimately reducing the
number of panicles per unit land area (Murty and Murty, 1982). A sufficient solar radiation is available after flowering in
‘kharif’ rice crop normally. Low light intensity is likely to reduce the harvest index (HI) because of inadequate grain filling.
High photosynthesis rate at low light may be strategized with high light harvesting efficiency, high chlorophyll content,
greater dry matter production and HI. (Sahu, et.al.,1980).
This correlation studies among the physiological parameters implies that by putting high selection pressure on these
physiological parameters (yield with yield attributes), other genotypes/strains could be identified, and improved through
properly oriented breeding programmers in desired direction. Improvement of the traits in the development of genotypes with
high physiological efficiency will lead to higher yield in kharif (wet season) rice under agro-ecological conditions of Assam
11. International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-3, March- 2016]
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and elsewhere. This was in agreement with the findings of Mishra et al. (1967). Sahu et al (1983) stated that yield is related
to LAI and dry matter at flowering (source size) during the wet season. Murty et al (1974) found a high correlation of grain
number (sink size) with yield during the dry season. A positive relationship between net carbon assimilation and leaf
nitrogen content in rice was also shown by Yoshida and Cornel (1976); Sinclair and Horie (1989).
VIII. CONCLUSION
The foregoing investigation into the effects of different light regimes on the rice crop revealed that low light and even red
light reduce most of the physiological parameters in comparison to normal white light. So, it can be inferred that the most
favorable illumination condition for proper growth and development of rice crop is the white light with the required bright
sunshine hours.
ACKNOWLEDGEMENTS
The authors express deep sense of gratitude to Assam Agricultural University for providing all necessary field and laboratory
facilities to accomplish the experiments in time. All helps received from Dr. S.C. Dey, the former Head of the department of
Crop Physiology, Dr. U.S. Das, former Statistician, AAU, Jorhat are duly acknowledged.
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