In recent years, the talk on Organic Farming is going on. how can we control the weed plants in the field without using the herbicide the question. there are several methods traditionally used and scientifically proved methods are discussed here.
An integrated weed management approach to land management combines the use of complementary weed control methods such as grazing, herbicide application, land fallowing, and biological control.
In recent years, the talk on Organic Farming is going on. how can we control the weed plants in the field without using the herbicide the question. there are several methods traditionally used and scientifically proved methods are discussed here.
An integrated weed management approach to land management combines the use of complementary weed control methods such as grazing, herbicide application, land fallowing, and biological control.
Worms Eat My Garbage - Composting Earthwormssodj49v
Waste Not, Want Not - Composting All Organic Waste in several weeks, and creating Super Soil for high yield organic gardening production. Worm Composting creates Worm Tea for use as an organic fertilizer and plant disease control.
The pattern of field infestation by the flea beetles, Podagrica spp., was assessed in okra-kenaf intercrop system with a view to determining a cropping pattern that would assist in controlling the pest problem. Okra and kenaf were intercropped in row combinations of 1:1, 1:2, 2:1 and 2:2 while sole-cropped okra and kenaf served for comparison. Field sampling for flea beetles commenced three weeks after planting and it lasted till the 12th week, a period that extended to the postharvest stage of okra. There was a significant difference (P Ë‚ 0.01) between the population of the two Podagrica spp. (with P. uniforma being more abundant than P. sjostedti) and among the six planting patterns. The pest population also differed (P Ë‚ 0.05) between the two crops and among (P Ë‚ 0.001) the vegetative, reproductive and postharvest stages of okra. Sole kenaf had a significantly higher level of infestation by the flea beetles followed by sole okra and two rows of okra intercropped with one row of kenaf in descending order. All the other three intercrop patterns had a significantly lower infestation level. Kenaf attracted more flea beetles than okra at the vegetative stage while stumps of okra left in the field after harvesting was over sustained a significantly higher population of flea beetles. Obtained results showed that intercropping could be used, especially by poor rural farmers, as a pest control strategy against Podagrica spp. Due to the considerable population of flea beetles sustained by okra stumps, farmers should be encouraged to get rid of leftovers after harvesting as a way of further controlling Podagrica spp. The combination of intercropping and farm sanitation would assist in reducing reliance on synthetic chemical insecticides.
Out Crossing, Heterozygosis and Inbreeding with Environments Interaction in R...paperpublications3
Abstract:The progenies of five sorghum heterozygous populations’ cycles were tested under main and off-season on two different environments irrigated and rainfall conditions for their outcrossing, heterozygosity and inbreeding coefficient using SSR markers,the marker combinations were optimized according to their fragment size. Multi-locus outcrossing rate (tm) and average single-locus (ts) outcrossing rates were estimated using the MLTR software, and TFPGA computer program. The outcrossing rate effected directly by the temperature and relative humidity (RH) during the initial flowering period, which the low temperature with high RH under main season is revealed positive increased in outcrossing than off-season. Progenies outcrossing rate revealed same trend with main population outcrossing and the same trend was observed heterozygosity with decreased in inbreeding coefficient. Higher levels in outcrossing rate and heterozygosity was detected under rainfall environment in two based population progenies, but in three advanced population cycles the outcrossing rate was higher under irrigated than rainfed environment. Inbreeding coefficient revealed negative relation with outcrossing rate and heterozygosity in different population’s progenies.
Evaluating Kenyan Dolichos (Lablab purpureus L.) Genotypes for Resistance to ...Premier Publishers
The objective of this study was to evaluate eighteen Dolichos lablab genotypes for resistance to Maruca vitrata and Helicoverpa armigera in the field using morphological markers. The study design was Randomized Complete Block (RCBD) with separation of mean done using Turkey’s range of test. Eldoret, KALRO Njoro and KALRO Kakamega were the study sites. Morphological parameters of pods were studied to determine whether they have any influence on resistance of Dolichos lablab to M. vitrata and H. armigera. The pod damage (%) of each genotype was calculated and given a resistance rating of 1-5 score damage. Genotype G2, Bahati and W7 were resistant to M. vitrata in a scale of 1(0-10%; low infestation), Bahati and W7 were moderately resistant to H. armigera in a scale of 2(11-30%; moderate infestation). Genotype LG1MoiP10 was susceptible to M. vitrata in a scale of 4 (51-70%; severe infestation) and genotype M5 was intermediate to H. armigera in a scale of 3 (31-50%; high infestation). There was positive significant correlation in H. armigera and M. vitrata pod damage with days to maturity, growth habit, and pod attachment. Pod length and pod fragrance were positively correlated to M. vitrata. Negative correlation was detected in pod thickness, pod pubescence and raceme position to pod damage by H. armigera and M. vitrata. The study identified G2, Bahati and W7 as promising resistant genotypes and can be used in Dolichos breeding program. However, there is need to further evaluate them in different environments and seasons for reliability.
Out Crossing, Heterozygosis and Inbreeding with Environments Interaction in R...paperpublications3
Abstract:The progenies of five sorghum heterozygous populations’ cycles were tested under main and off-season on two different environments irrigated and rainfall conditions for their outcrossing, heterozygosity and inbreeding coefficient using SSR markers,the marker combinations were optimized according to their fragment size. Multi-locus outcrossing rate (tm) and average single-locus (ts) outcrossing rates were estimated using the MLTR software, and TFPGA computer program. The outcrossing rate effected directly by the temperature and relative humidity (RH) during the initial flowering period, which the low temperature with high RH under main season is revealed positive increased in outcrossing than off-season. Progenies outcrossing rate revealed same trend with main population outcrossing and the same trend was observed heterozygosity with decreased in inbreeding coefficient. Higher levels in outcrossing rate and heterozygosity was detected under rainfall environment in two based population progenies, but in three advanced population cycles the outcrossing rate was higher under irrigated than rainfed environment. Inbreeding coefficient revealed negative relation with outcrossing rate and heterozygosity in different population’s progenies.
Keyword:environment, recurrent selection, outcrossing, sorghum, progenies.
A SEMINAR REPORT ON POLLEN MICROBES BY TEMIDAYO FARORK OLAPADE.
Microorganisms including fungi, bacteria, and viruses live in flowers and are thought to affect pollination. Microbial influence the effectiveness of pollinator visits is poorly understood and depends on the context. The effect of microbes on pollen performance is underappreciated. Beyond the effect of pathogenic viruses, the impacts of pollen-transmitted endophytic microbes on pollen viability or tube growth are unknown but could affect the outcome of pollen receipt. Future research integrating microbes into pollination should broaden taxonomic diversity of microbes, pollinators and plants and the processes under study. Crops aimed at feeding an exponentially growing population are often exposed to a variety of harsh environmental factors. Although plants have evolved ways of adjusting their metabolism and some have also been engineered to tolerate stressful environments, there is still a shortage of food supply. An alternative approach is to explore the possibility of using rhizosphere microorganisms in the mitigation of abiotic stress and hopefully improve food production. Several studies have shown that rhizobacteria and mycorrhizae organisms can help improve stress tolerance by enhancing plant growth; stimulating the production of phytohormones, siderophores, and solubilizing phosphates; lowering ethylene levels; and upregulating the expression of dehydration response and antioxidant genes.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium...researchagriculture
Cabbage aphid (Brevicoryne brassicae L.) is one of the most problematic pests in smallholder vegetable production, causing significant yield losses in heavy infestations. Current control strategy focuses on use of synthetic pesticides that consequently lead to decimation of natural enemies, development of insect resistance and resurgence and upset biodiversity. Botanical pesticides have been used widely in smallholder farmers but not much documented literature exists on efficacy of these products. A field trial was done to assess the efficacy of crude aqueous extracts of Tephrosia vogelii, Allium sativum and Solanum incanum in controlling Brevicoryne brassicae in Brassica napus production. The trial was laid in a randomized complete block design (RCBD) with five treatments replicated four times. The five treatments used in the experiment were T. vogelii, A. sativum, S. incanum, dimethoate and control. Wingless adult female aphids were inoculated three weeks after transplanting of seedlings. Spraying and data collection were done weekly for four weeks. Data was collected on aphid nymph and adult counts on the third leaf from the aerial plant part of randomly selected plants from each treatment for 24 hours after the application of treatments and total plant fresh weight per each treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that T. vogelii, S. incanum and A. sativum aqueous crude extracts have some pesticidal effects on aphid in rape production.
Article Citation:
Shepherd Mudzingwa, Simbarashe Muzemu and James Chitamba.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium sativum L. and Solanum incanum L. in controlling aphids (Brevicoryne brassicae L.) in rape (Brassica napus L.)
Journal of Research in Agriculture (2013) 2(1): 157-163.
Full Text:
http://www.jagri.info/documents/AG0040.pdf
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Alli...researchagriculture
Cabbage aphid (
Brevicoryne brassicae
L.) is one of the most problematic
pests in smallholder vegetable production, causing significant yield losses in heavy
infestations. Current control strategy focuses on use of synthetic pesticides that
consequently lead to decimation of natural enemies, development of insect
resistance and resurgence and upset biodiversity. Botanical pesticides have been used
widely in smallholder farmers but not much documented literature exists on efficacy
of these products. A field trial was done to assess the efficacy of crude aqueous
extracts of
Tephrosia vogelii
,
Allium sativum
and
Solanum incanum
in controlling
Brevicoryne brassicae
in
Brassica napus
production. The trial was laid in a randomized
complete block design (RCBD) with five treatments replicated four times. The five
treatments used in the experiment were
T
.
vogelii
,
A
.
sativum
,
S
.
incanum
,
dimethoate and control. Wingless adult female aphids were inoculated three weeks
after transplanting of seedlings. Spraying and data collection were done weekly for
four weeks. Data was collected on aphid nymph and adult counts on the third leaf
from the aerial plant part of randomly selected plants from each treatment for
24 hours after the application of treatments and total plant fresh weight per each
treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that
T. vogelii
,
S
.
incanum
and
A
.
sativum
aqueous crude extracts have some pesticidal
effects on aphid in rape
production.
Wheat-pea intercropping for aphid control: from laboratory tritrophic approac...InternationalNetwork
Intercropping is an interesting practice to promote the sustainable control of insect pests such as aphids. In particular, volatile organic compounds emitted by aphid-infested intercropped plants may deter other aphid species from their host plants, while attracting natural enemies. In this study, olfactometer and net-cage behavioural assays were first conducted to determine the effect of wheat-pea mixtures combined with aphid infestations on odour preferences of the wheat aphid Sitobion avenae and two associated predator species, the ladybird Harmonia axyridis and the hoverfly Episyrphus balteatus. Healthy wheat plants were preferred by S. avenae, while wheat-pea mixtures combined with aphid infestations were significantly less attractive. H. axyridis preferred odours from healthy wheat plants mixed with aphid-infested pea plants. As for E. balteatus, their searching and oviposition behaviours were stimulated by the different wheat/pea combinations associated with aphid infestations. A field trial was also carried to compare the effect of mix and strip cropping wheat with pea on aphids and their natural enemies with both monocultures. Wheat and pea aphid populations were significantly reduced by both types of intercropping when compared to monocultures. Moreover, higher abundances of hoverflies, lacewings and ladybirds were found in wheat mixed with pea field, followed by strip cropping and monocultures. These findings show that wheat-pea intercropping can be efficient to reduce aphid populations, namely by promoting their biological control.
Assessment of forage corn quality intercropping with green beans under influe...Innspub Net
To assess the quality of forage corn intercropping with green beans under the influence of Rhizobium bacteria and Arbuscular Mycorrhizal fungus, make a test in educational-research farm of agriculture faulty of Azna PNU that it was design in factorial to randomized complete block with three replications. The experimental factors include cropping systems such as mono cropping of corn, mono cropping of green beans, intercropping, Arbuscular Mycorrhizal fungus (use and non-use) and Rhizobium bacteria (use and non-use). The results showed that cropping systems on crude protein, wet forage weight, dry forage weight were significant at 1% level as well as leaf to stem ratio was significant at 5% level. Between different levels of bacteria used, acid detergent fiber was impressed and was significant at 5% level. Arbuscular Mycorrhizal fungus was significant at 5% level on water soluble carbohydrate. The results showed that the use of separate and combined of Rhizobium bacteria and Arbuscular Mycorrhizal fungus increase the quality of corn in intercropping than mono cropping. Finally with increasing of plant diversity and microorganism in soil increased the quality and quantity of forage. Get the full articles at: http://www.innspub.net/volume-6-number-5-may-2015-jbes/
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Using Clovers as Living Mulches to Boost Yields, Suppress Pests, and Augment Spiders in a Broccoli Agroecosystem
1. Insect Pests
May 2007
IP-27
Using Clovers as Living Mulches
To Boost Yields, Suppress Pests, and Augment Spiders
in a Broccoli Agroecosystem
Cerruti R2 Hooks,a Raju R. Pandey,b and Marshall W. Johnsonc
a
CTAHR Department of Plant and Environmental Protection Sciences; bHimalayan College of Agricultural Sciences and Technology,
Kathmandu, Nepal; cDepartment of Entomology, University of California, Riverside
Summary economically important crop with an undersown plant
A field study was conducted to examine the influence of species that has no direct market value but is used to di
intercropping broccoli (Brassica oleracea L.) with three versify the agroecosystem or influence the main crop.
living mulches on caterpillar pest and spider densities The impact on insect pest densities of undersowing
and crop yield. Broccoli was grown in bare ground or vegetable crops with living mulches has been examined
intercropped with strawberry clover (Trifolium fra- mainly in Brassica crops (Asman et al. 2001; Hooks
giferum L.), white clover (Trifolium repens L.), or yel and Johnson 2001, 2002). In most of these studies,
low sweetclover (Melilotus officinalis L.). Lepidopteran fewer insect pests were found on interplanted vegetable
(butterfly and moth) eggs and caterpillar densities were crops (Hooks and Johnson 2003 and references therein).
significantly greater on broccoli in bare-ground plots However, Brassica crops are typically slow growing
compared with broccoli intercropped with clover dur and do not compete well with background vegetation.
ing the late broccoli growth cycle. More spiders were Therefore, most of these studies reported significant
found on bare-ground broccoli during early crop growth; yield reductions, possibly caused by interspecies com
however, during the later growth period, spider counts petition.
were significantly higher on broccoli in intercropped Several strategies may be implemented to limit com
plots. The number of insect contaminants found in petition among Brassica crops and their companion
harvested broccoli crowns were significantly less in plants. These strategies may include
intercropped than in bare-ground broccoli plots. The • proper fertilization and irrigation of the main crop
weight of harvested crowns was similar in intercropped • use of vigorous or rapidly growing crop cultivars
and bare-ground habitats. • optimal spacing between the main crop and compan
ion plants
Introduction • use of less competitive background plants (e.g., low
An established cover crop that is interplanted and grown canopy height)
with an annual row crop is known as a living mulch. • timely planting of the main crop and companion plant
Living mulches can provide many benefits to a crop • planting the intercrop at a lower seed rate or in nar
ping habitat, including weed control, reduced erosion, rower strip
enhanced fertility, and improved soil quality (Lanini et • suppression of the intercrop (e.g., mowing, reduced
al. 1989). However, recent studies have shown that when fertilization and irrigation) at critical times
living mulches are undersown with a vegetable crop • use of a self-suppressing companion plant (i.e., one
they can also help reduce injury imposed by insect pests that dies during the critical period of crop growth)
(Costello and Altieri 1995, Hooks et al. 1998, Hooks and • use of non-crop borders surrounding the field crop.
Johnson 2001). Undersowing is the intercropping of an
Published by the College of Tropical Agriculture and Human Resources (CTAHR) and issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in coopera
tion with the U.S. Department of Agriculture. Andrew G. Hashimoto, Director/Dean, Cooperative Extension Service/CTAHR, University of Hawai‘i at Mänoa, Honolulu, Hawai‘i 96822.
An equal opportunity/affirmative action institution providing programs and services to the people of Hawai‘i without regard to race, sex, age, religion, color, national origin, ancestry, dis
ability, marital status, arrest and court record, sexual orientation, or status as a covered veteran. CTAHR publications can be found on the Web site <http://www.ctahr.hawaii.edu/freepubs>.
2. UH–CTAHR IP-27 — May 2007
Each approach should be viewed with caution and Arthropod census
weighed against its potential to negate any positive Caterpillar pest stages and predators on broccoli plants
benefits of pest suppression. were sampled at 7-day intervals until the harvest period.
This publication describes a field experiment that Sampling was stratified according to plant structure (5
was part of a continuing effort to refine management of upper, 10 middle, and 10 lower positioned leaves). Egg,
lepidopteran pests in broccoli by mixed cropping and caterpillar, and pupa stages of the diamondback moth,
undersowing it with other plant species. The primary pur Plutella xylostella L., imported cabbageworm, Pieris
pose of this study was to determine if specific undersown rapae L, and cabbage looper, Trichoplusia ni Hübner,
living mulches would have the ability to suppress lepi were counted separately.
dopteran pest densities without reducing crop yields to
economically unacceptable levels. We focused on cover Broccoli yield
crops in the genus Trifolium partially because of their The diameter and weight of 16 broccoli crowns, chosen
low-growing structural similarities to yellow sweetclover. at random from the interior rows of each plot, were mea
Additionally, because spiders were recurrently observed sured at harvest time. The heads were then completely
preying on various lepidopteran caterpillars (Hooks and dissected and examined for insects, insect parts, and as
Johnson 2002), their densities were compared among sociated contaminants (e.g., frass, webbing, cocoon).
undersown and bare-ground broccoli.
Statistical analysis
The effects of habitat type on the experimental param
Materials and methods
eters were analyzed using analysis of variance (Proc
Experiment layout GLM, SAS Institute, Cary, NC 1990) and predetermined
The field experiment was conducted during the summer orthogonal comparisons to separate mean differences.
2000 at the University of Hawai‘i at Mänoa’s Poamoho Within the model, the following predetermined contrasts
Research Station on O‘ahu. The four cropping systems were conducted: broccoli-clovers vs. monoculture; true
examined were broccoli plants undersown with: (1) yel clovers (white and strawberry) vs. yellow sweetclover;
low sweetclover (Melilotus officinalis L.) seeded at 72 g and strawberry clover vs. white clover. Because eggs of
per row, (2) strawberry clover cv. O’Conners (Trifolium moths and butterflies were acutely low, all species were
fragiferum L. seeded at 58 g per row, (3) white clover pooled together by stage (e.g., egg, larvae) prior to final
cv. New Zealand (Trifolium repens L.) seeded at 54 g analysis. The criteria for significance was P < 0.05.
per row, and (4) broccoli monoculture used as a check
treatment. Experimental plots were 11 m x 11 m with
Results
each treatment replicated four times and arranged in a
randomized complete block design. Clover growth
The living mulches were sown on 10 July 2000 in all of The yellow sweetclover canopy expanded over the soil
the undersown plots. Undersown plots contained 10 rows surface faster than the other undersown living mulches.
of broccoli with 11 rows of the living mulch species and Subsequently, the amount of exposed soil surface area
monoculture plots contained 10 rows of broccoli. Broccoli between broccoli rows was significantly less in broc
seedlings, cv. Liberty (Petoseed Co., Saticoy, California), coli–yellow sweetclover contrasted with broccoli under
were grown for 5 weeks in the greenhouse before being sown with strawberry clover and white clover on each
manually transplanted on September 18 and 19. sampling date. Strawberry clover canopy development
occurred at the slowest rate and was significantly less
Clover growth than that of white clover on most dates.
The spread of the clover canopies was monitored weekly
beginning 16 days after broccoli planting (DAP) until Arthropod census
broccoli harvest. Five areas between two adjacent clover Effect of clovers on leidopteran pest densities. Lepi
rows in each plot were randomly selected, excluding dopteran populations were low during the experiment.
border rows, and the distance of exposed soil surface (not Approximately 85, 10, and 5 percent of the lepidopteran
covered by clover canopy) between rows was measured. fauna observed were P. rapae, T. ni, and P. xylostella,
2
3. UH–CTAHR IP-27 — May 2007
Figure 1. Mean population densities of lepidopteran (a) eggs and (b) larvae in bare-ground broccoli (BG); broccoli–
strawberry clover intercrop (SC); broccoli–white clover intercrop (WC); and broccoli–yellow sweetclover intercrop (YSC).
Figure 1.
*** indicates intercrops significantly less than bare ground; s indicates (SC) significantly less than (WC); w indicates (WC)
significantly less than (SC); y indicates (YSC) significantly less than (SC + WC); and ns means no significant differences
exist (P > 0.05).
0.7
BG eggs A
0.6 ***
SC
0.5 WC
Number of lepidopteran per leaf leaf
YSC
0.4
Number of lepidopteran per
0.3 s ***
ns ns
0.2 ns
ns
0.1
0
0.8 B
larvae ns
0.7
0.6
0.5
0.4 w
***
0.3 y *** y ***
0.2
0.1 ***
0
16 23 30 37 44 51 58
Days after planting
Days After Planting
respectively. From early to mid-season, no significant mordax L. Koch (Clubionidae) composed approximately
differences were detected in the abundance of eggs 77, 13, 7, and 3 percent of the spider fauna, respectively.
among broccoli habitats (Figure 1a). However, during Significantly fewer spiders were encountered on broccoli
the late broccoli growth cycle, more eggs were found plants with clovers compared with bare-ground broccoli
in monoculture than in undersown broccoli. Similarly, during the initial three sampling dates. However, during
more caterpillars were recorded in monoculture com the later part of the broccoli growth cycle, this trend re
pared with undersown broccoli from mid- to late season versed, and more spiders were found on broccoli plants
(Figure 1b). in clover than in bare-ground plots (Figure 2).
Impact of clovers on spider abundance. At the ex Additionally, fewer spiders were found on broccoli
perimental site, four spider species frequently inhabit grown with the true clovers (e.g., strawberry clover,
Brassica plants. Nesticodes (= Theridion) rufipes Lucas white clover) compared with plants grown with yellow
(Theridiidae), Neoscona oaxacensis Keyserling (Ara sweetclover during mid-season. Fewer spiders were also
neidae), Oxyopes sp. (Oxyopidae), and Cheiracanthium observed on broccoli plants undersown in strawberry
3
4. UH–CTAHR IP-27 — May 2007
Figure 2. Mean population densities of spiders in bare-ground broccoli (BG); broccoli–strawberry clover intercrop (SC);
Figure 2.
broccoli–white clover intercrop (WC); broccoli–yellow sweetclover intercrop (YSC). * indicates (BG) significantly less
than intercrops; *** indicates intercrops significantly less than (BG); c indicates (SC + WC) significantly less than (YSC);
s indicates (SC) significantly less than (WC); and ns means no significant differences exist (P ≥ 0.05).
1
Number of spiders per leaf
BG
Number of spiders per leaf
0.8 SC *cs
WC
***
YSC
0.6
* s
*** c
0.4 ***
0.2
0
16 23 30 37 44 51 58
Days after planting
Days After Planting
clover compared with white clover from mid- to late reducing crop yields to unacceptable levels. We found
season. that the number of insect contaminants per broccoli
crown was significantly reduced on plants undersown
Crown contamination with strawberry clover and white clover compared to
At harvest, broccoli crowns were infested with various bare-ground broccoli without causing any yield reduc
stages of Pieris rapae, Trichoplusia ni, and Plutella tions. Additionally, spider densities found on broccoli
xylostela (Table 1). T. ni caterpillars and pupae were the plants seemed to be influenced by the amount of clover
most abundant lepidopteran contaminants encountered in canopy. As the clover canopies expanded and approached
broccoli heads. However, significantly more individuals the broccoli plants, more spiders were found on the
of all three species were found in crowns harvested from broccoli foliage.
bare-ground broccoli compared to undersown broccoli.
Impact on spider abundance
Crop yield During the early part of the season, the living mulches
The largest crowns by diameter and mass were harvested may have negatively influenced biological control activ
from broccoli undersown with strawberry clover or ity on broccoli plants by serving as a “sink” for spiders.
white clover (Table 2). These crowns weighed signifi Spiders may have preferred the micro-environment
2
cantly more than those harvested from broccoli–yellow and prey selection within the clovers and thus did not
sweetclover plots. Yellow sweetclover plots contained colonize neighboring broccoli plants. Similar observa
the smallest crowns, by weight. tions were made in previous field experiments in which
fewer spiders were found on broccoli plants intercropped
Discussion with peppers or yellow sweetclover, but as the season
The purpose of this study was to determine if undersown progressed these differences diminished.
clovers could reduce lepidopteran pest densities without
4
5. UH–CTAHR IP-27 — May 2007
Table 1. Mean number of lepidopterans per broccoli head in four broccoli habitats during summer 2000 (mean ± SE).
Habitat Pieris rapae Trichoplusia ni Plutella xylostella Total
Bare ground 0.1 + 0.0 0.8 + 0.10 0.13 + 0.0 0.87 + 0.0
Broccoli-SC 0.08 + 0.04 0.10 + 0.04 0.00 + 0.00 0.18 + 0.06
Broccoli-WC 0.0 + 0.03 0.00 + 0.00 0.02 + 0.02 0.07 + 0.03
Broccoli-YSC 0.0 + 0.03 0.12 + 0.0 0.03 + 0.02 0.20 + 0.06
Contrast1 P-value
BG vs. LMs 0.03 0.01 0.006 0.0001
TCs vs. YSC 0.07 0.4 0.4 0.39
SC vs. WC 0.0 0.62 0.67 0.20
1
SC (strawberry clover), WC (white clover), YSC (yellow sweetclover), BG (bare ground, broccoli monoculture); LMs (living mulches) includes
broccoli-SC, broccoli-WC, and broccoli-YSC; TCs (true clovers) includes broccoli-SC and broccoli-WC.
Conclusion
Table 2. Mean head size per broccoli plant in four habitats
Using undersown living mulches seems to be promising during summer 2000.
in reducing lepidopteran pest densities and increasing
Broccoli parameters1
the activity of spiders in broccoli plantings. In this study, (mean ± SE)
white clover appeared to be more suited for the broccoli
Habitat Diameter (cm) Weight (kg)
system. White clover expands over the soil surface faster
than strawberry clover and may therefore be a better Bare ground 13.0 + 0.3 0.3 + 0.01
weed suppressor. For those farmers looking to create
Broccoli-strawberry clover 14.7 + 0.3 0.40 + 0.02
more sustainable cropping practices or practicing organic
farming, undersowing may be a valuable addition to their Broccoli-white clover 14.4 + 0.24 0.39 + 0.01
crop production practices. Broccoli-yellow sweetclover 13.7 + 0.28 0.33 + 0.01
This field trial showed that it is possible to lower insect
pest density while maintaining crop quality and yield. Effect2 P -Values
However, insect pest management is only one potential Planned contrast
BG vs. LMs 0.0002 0.11
benefit of using leguminous living mulches. Other po TCs vs. YSC 0.03 0.000
tential benefits not examined during this study include SC vs. WC 0.71 0.1
nematode and weed suppression and enhancement of
soil nitrogen. However, before an undersown compan 1
Multiply cm by 0.394 to obtain inches, and multiply kg by 2.2 to
obtain pounds.
ion plant is chosen for insect suppression purposes, its 2
SC (strawberry clover), WC (white clover), YSC (yellow sweetclover),
impact on other important organisms associated with the BG (bare ground, broccoli monoculture); LMs (living mulches) include
crop should be considered. broccoli-SC, broccoli-WC, and broccoli-YSC; TCs (true clovers)
include broccoli-SC and broccoli and broccoli-WC.
Acknowledgements
The authors wish to thank the crew at the Poamoho References and further reading
Research Station for assisting in the field and Dr. Raju Asman, K., B. Ekbom, and B. Rämert. 2001. Effect of
Pandey for his notable contributions to this study. This intercropping on oviposition and emigration behavior
project was funded by the USDA/CSREES Special of the leek moth (Lepidoptera, Acrolepiidae) and the
Grant for Tropical and Subtropical Agriculture Research diamondback moth (Lepidoptera, Plutellidae). Envi
(T-STAR). ronmental Entomology 30: 288–294.
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