Genotypic Variation in Cowpea (Vigna unguiculata (L.) Walp.) for Resistance to Pulse Beetle (Callosobruchus maculatus F.) and the Protective Effects of Botanical Powders
Jul 2026· Asian Journal of Research in Crop Science· Vol 11, pp. 66-78· 0 citations
Abstract
Cowpea (Vigna unguiculata (L.) Walp.) is a significant grain legume commonly grown in tropical and subtropical regions and is an important source of protein, vitamins, and minerals for humans and livestock. Nevertheless, storage losses caused by the pulse beetle, Callosobruchus maculatus (F.), continue to constrain cowpea production and storage, particularly in sub-Saharan Africa. This study assessed varietal resistance and botanical powders as alternative protectants against C. maculatus infestation under in vitro conditions at the Savannah Agricultural Research Institute (CSIR-SARI), Nyankpala, Ghana. The experiment used a split-plot factorial arrangement in a randomised complete block design (RCBD) with three replications. The main plots comprised four cowpea varieties (Padituya, Songotra, Apagbaala, and Zaayura), while the subplots comprised five protectant treatments (untreated control, neem seed powder, basilicum powder, hyptis powder, and Phostoxin). Data were collected on oviposition, developmental period, adult mortality, progeny emergence, grain damage, and grain weight loss. Significant interaction effects between variety and protectant were observed for oviposition, adult emergence, and mortality of C. maculatus. Songotra and Zaayura recorded lower oviposition, adult emergence, grain damage, and grain weight loss than Apagbaala and Padituya. Phostoxin produced the lowest adult emergence and highest mortality, while neem seed and basilicum powders similarly reduced oviposition, progeny emergence, and grain damage. Hyptis powder provided comparatively lower protection. These findings indicate that combining resistant varieties, particularly Songotra and Zaayura, with neem seed or basilicum powder may improve the protection of stored cowpea grains and provide a more environmentally favourable alternative to synthetic insecticides.
Cowpea is a grain legume, rich in proteins, carbohydrates, vitamins, and minerals. It enriches the soil through its
biological nitrogen fixation capacity, thanks to rhizobia associated with its roots. Unfortunately, in sub-Saharan Africa,
particularly in the Democratic Republic of Congo, within the territory of Tshilenge, the production of this crop faces biotic
constraints. The most frequent diseases are anthracnose, cercosporiosis, and viral mosaic, as well as attacks by Anoplocnemis
curvipes and Ootheca mutabilis. As a hypothesis for this study, we assume that certain cowpea cultivars would be tolerant
while others would be susceptible to the major pathologies and pests in the Tshilenge region. The objective of this study is
to identify the most tolerant and most susceptible cowpea cultivars to major pathological and pest pressures on sub-Saharan
ferralsols in the Tshilenge region, Kasaï Oriental, through experimentation at different sowing dates. The results reveal that
certain cultivars stand out for their remarkable tolerance, while others express increased susceptibility to major pathologies
and pests. Cultivars C6 (index = 0), C1 (0.708), and C14 (0.744) are the most tolerant; their low index reflects high tolerance
and stability against various pathogenic and entomological pressures. Conversely, cultivars C13 (2.95), C9 (2.97), and C8
(3.00) are highly susceptible; their high index reflects strong vulnerability to diseases, limiting their agronomic value under
conditions of high pathogenic and entomological pressure.
Tshibamba Mukendi John, Mpiana Tshimanga Vincent, Landu Ndambu Gaston et al.· International Journal of Inn...· 0 citations
Callosobruchus maculatus (F.) is a devastating storage pest of cowpea, causing significantlosses if left uncontrolled. This study evaluated the response of 411 cowpea genotypes toC. maculatus infestation to identify novel sources of resistance and investigate associations between bruchid growth, damage parameters, and resistance metrics. The experiment was conducted at Entomology Laboratory, Department of Zoology, Ahmadu Bello University, Zaria using completely randomized design (CRD). A no-choice assay was employed to screen cowpea genotypes, and data were collected on bruchid growth, damage parameters, and seed morphometric traits. Statistical analysis revealed significant differences (p <0.05) among genotypes for all measured traits, indicating substantial variability for bruchid resistance. Five genotypes (ABU_Vu16, ABU_Vu39, ABU_Vu225, ABU_Vu239, and ABU_Vu309) showed high bruchid tolerance (>70%) and low Dobie susceptibility index (DSI) values (<3). Negative associations were observed between percentage pest tolerance and adult emergence, growth index, and DSI, suggesting that selecting for lower values of these traits can enhance bruchid resistance. Our findings identify reliable indicators of bruchid resistance in cowpea and highlight the potential of these genotypes for developing sustainable storage pest management strategies using a multi-trait approach. This approach is essential, as various factors influence the bruchid resistance trait
Mahmud J, N. S· Biological and Environmental...· 1 citation
Botrytis grey mold (BGM), caused by Botrytis cinerea, is an important constraint to chickpea production in humid environments of Nepal. Field experiments were conducted at the Oilseed Research Program, Nawalpur, Sarlahi, Nepal, during the winter seasons of 2079/80 and 2080/81 to evaluate 12 elite chickpea genotypes, including released variety Tara as a standard check, received from Grain Legumes Research Program, Khajura, Banke for BGM response and yield performance. The experiment was conducted in a randomized complete block design with three replications. Data were recorded for phenological, agronomic and yield traits, along with BGM severity. Significant genotypic variation (P<0.05) was observed for BGM severity, flowering and maturity days, plant height, pods/plant and grain yield. Mean BGM severity decreased from 59.0% in the first year to 45.8% in the second year, while mean grain yield increased from 1017.7 to 1275.4 kg /ha. ICCV 87312 showed the lowest BGM severity in both years (44.4 and 31.5%) and recorded the highest grain yield in the second year (1773.7 kg/ha). KWR 108 also showed comparatively low and consistent BGM severity (44.4 and 38.9%) with good yield performance. The genotype × year interaction for BGM severity was non-significant indicating relatively consistent genotype responses across seasons. ICCV 87312 and KWR 108 are promising genotypes for further multi-location evaluation and breeding for moderate BGM resistance combined with high yield in Nepal.
Unknown authors· Nepal Agriculture Research J...· 0 citations
Cowpea (Vigna unguiculata (L.) Walp.) is an important warm-season multipurpose legume valued for its
nutritional quality, adaptability, and contribution to sustainable agriculture. Morphological
characterization of germplasm is essential for the identification of distinct genotypes, assessment of
phenotypic diversity, and selection of suitable parental lines for crop improvement programmes. The
present investigation was undertaken to characterize the morphological diversity of thirty vegetable
cowpea genotypes using qualitative descriptors under summer conditions. The experiment was
conducted during the summer of 2024 at the Vegetable Research Farm, Regional Horticultural Research
Station (RHRS), ASPEE College of Horticulture, Navsari Agricultural University, Navsari, Gujarat.
Thirty genotypes, including twenty-nine diverse accessions and one standard check (Pusa Phalguni),
were evaluated in a Randomized Complete Block Design with three replications under three sowing
dates. Ten qualitative morphological traits were recorded following the standardized IPGRI/IITA
cowpea descriptor guidelines. Substantial phenotypic variation was observed for all qualitative
descriptors, indicating the presence of a broad genetic base among the evaluated genotypes. Plant growth
habit varied from erect (26.7%) and semi-erect (23.3%) to bush (20.0%), pole type (20.0%), and
horizontal (10.0%). Kidney-shaped seeds were predominant (43.3%), followed by elliptical (33.3%) and
rhomboid (23.3%) seeds. Considerable variation was also recorded for climbing tendency, plant
pigmentation, terminal leaflet shape, leaf colour, leaf texture, flower colour, pod curvature, and mature
pod colour. Flower colour was equally represented by white, yellow, and purple types, while curved pods
and green mature pods were the most frequent phenotypes. The observed diversity demonstrates the
distinct morphological identity of the evaluated germplasm and highlights the usefulness of qualitative
descriptors for varietal characterization. The wide range of morphological variation observed among the
cowpea genotypes provides valuable genetic resources for germplasm conservation and characterization.
Genotypes possessing desirable traits such as erect growth habit, non-climbing tendency, kidney-shaped
seeds, and straight green pods may serve as promising parental lines for vegetable cowpea improvement
programmes aimed at developing high-yielding and agronomically superior cultivars
M. N., V. Parmar, Y. Tandel et al.· Plant Archives· 0 citations
Cowpea (Vigna unguiculata (L.) Walp.) is an important grain legume widely cultivated in sub-Saharan Africa for food security, nutritional supplementation, income generation, and soil fertility improvement. However, productivity of the crop is severely constrained by root-knot nematodes (Meloidogyne spp.), particularly the thermophilic species Meloidogyne incognita, Meloidogyne javanica and Meloidogyne enterolobii. The objective of this study was to determine the host status of six cowpea lines against M. javanica under greenhouse conditions. Two greenhouse experiments were conducted at the University of Limpopo, South Africa, using a randomised complete block design with six treatments replicated six times. Fourteen days after sowing, each seedling was inoculated with 3,000 eggs plus second-stage juveniles (J2) of M. javanica. Nematode assessments were conducted 56 days after inoculation. Reproductive potential (RP) was calculated as the ratio of final nematode population density to fresh root mass. Significant differences (P ≤ 0.05) were observed among cowpea lines for nematode reproduction. All test lines supported nematode reproduction, with RP values consistently exceeding unity. The findings demonstrate that all evaluated cowpea lines were susceptible hosts to M. javanica and are therefore unsuitable for deployment in crop rotation systems aimed at suppressing root-knot nematode populations. The study highlights the importance of incorporating nematode resistance screening into cowpea breeding programmes to support the development of integrated nematode management strategies under climate-smart agricultural systems.
K. P. Malatji, K. Pofu, A. Gerrano et al.· Research on Crops· 0 citations
The inverse relationship between larval weight and development duration highlights the role of maize genotype in influencing FAW growth dynamics, with resistant varieties prolonging development and suppressing larval biomass accumulation.
Susan Asekenye, M. Oyoo, K. Khakame· East African Journal of Agri...· 0 citations
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