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Cowpeas (Vignaunguiculata (L) walp) are one of the important plants in most African communities where they are grown. Cowpeas represent an easily transportable source of protein. Despite its importance, it confronted with numerous cultural constraints. This work was undertaken to evaluate the influence of number of plants per sowing point and seeding spacing on the growth and production of cowpea with a view to increasing cowpea yield. The trial was set up in a three replicates plot block design. The main plots consisted of the number of plants per sowing point (one plant per sowing point, two plants per sowing point and three plants per sowing point) at three spacing resulting in the following stand : Plots with a density of 20cm x 20cm had (225 ;450 ; 675) plants per sowing point, those with a density of 30cm x 30cm had (100 ;200 ; 300) plants per sowing point and finally those with a density of 40cm x 40cm had (56 ;112 ; 168) plants per sowing point. Observations were made on growth and yield parameters. The results showed that three plants per plot at high densities resulted in lower yields. Sowing two plants per sowing point at different spacing resulted in a 50% decrease in yield compared to sowing one plant per plot. On the other hand, the highest yield was obtained with the one plant per sowing point at low-density. On the other hand, the different spacing adopted induced significant effects for eight tenths of the observed parameters. The sowing of cowpea at 40 cm x 40 cm spacing with one plant per sowing point would effectively increase the yield of this crop in the city of Daloa. [ABSTRACT FROM AUTHOR]

The increasing demands for food, driven by shrinking arable land areas and a growing population, underscore the need for innovative agricultural practices to mitigate the effects of soil degradation due to salinity and promote food security, particularly in regions heavily impacted by salinity. In this study, we investigated the effects of inoculating the arbuscular mycorrhizal fungus (AMF) Rhizophagus clarus on the productivity of Vigna unguiculata cv. BRS Imponente plants in response to salinity (0, 25, 50, 75, and 100 mM). We found that NaCl concentrations ≥ 50 mM were phytotoxic, reducing plant growth and productivity. However, inoculation with AMF reduced plant oxidative stress (hydrogen peroxide concentration and lipid peroxidation) and ionic stress (Na+/K+ ratio). Inoculated plants exhibited increased antioxidant enzyme activity (ascorbate peroxidase and catalase), higher P and K concentrations, and lower Na concentrations in their leaves. As a result, salt did not interfere with grain production in the AMF-inoculated plants. For the first time, we demonstrate that inoculation with R. clarus can counteract the harmful effects of NaCl in V. unguiculata plants, ensuring their grain yields. Therefore, amid the escalating soil salinization globally, the AMF R. clarus emerges as a practical approach to ensure cowpea yields and enhance production in deteriorating agricultural lands, especially in saline areas. This can significantly contribute to promoting food security. [ABSTRACT FROM AUTHOR]

Determining the ecological plasticity and stability of varieties and hybrids of agricultural crops helps to comprehensively assess them, considering the productivity potential, qualitative technological indicators, and the level of resistance to stressful conditions. The purpose of this study was to investigate the development of the yield of beans of cowpea varieties with high ecological stability, plasticity, and adaptability. The leading methods of studying this problem are field-based - to determine the interaction of the research object with biotic and abiotic factors; statistical - to evaluate the results to determine the parameters of cowpea adaptability. Within the studied varieties, a direct and inverse correlation was established between the yield of cowpea and the sum of effective temperatures. For Groik (r = 0.36) and Kafedralna (Control) (R = 0.36), U-Cha-Kontou (r = -0.64) varieties, the correlation was average, while for Gasson (r = 0.96) and American improved (r = -0.98) varieties, it was strong. Based on the regression equations, an increase in the amount of precipitation by 1 mm can increase the yield of cowpeas by 3.4 kg/ha in the American improved variety and by 20.8 kg/ha - U-Cha-Kontou, and for the Gasson, Kafedralna (control), Groik varieties, there will be a decrease in yield by 6.4 kg/ha, 10.8 kg/ha, and 20.7 kg/ha, respectively. Varieties with high overall adaptive capacity, defined as the ability of genotypes to maximise the manifestation of traits under all environmental conditions, are valuable. High indicators of total adaptive capacity for plant yield were observed in the varieties Gasson (TAC = 5.16) and Groik (SAC = 2.16). The lowest value of this indicator was observed in the U-Cha-Kontou variety (TAC = -3.44). Varieties that produce high but unstable yields are not able to guarantee maximum yields in conditions of improper farming and difficult climatic conditions. The genotype breeding value is a complex indicator that determines the totality of productivity and stability of varieties. Studies have obtained such fluctuations in this indicator from 0.84 to 13.63. The best varieties in terms of genotype breeding value were Gasson (GBVi = 13.63) and Kafedralna (GBVi = 8.06). There is a relatively low yield stability and the ability to respond to improved growing conditions in the U-Cha-Kontou variety (GBVi = 0.84). [ABSTRACT FROM AUTHOR]

Cowpea (Vigna unguiculata L.) or kacang tunggak in Indonesian belongs to the Leguminoceae family and is recently still a less commercial crop. This study was conducted to determine irrigation volume based on pan evaporation and its effects on the growth, yield, and irrigation water use efficiency (IWUE) of cowpea (Vigna unguiculata L.) grown in the plastic house. The amount of water applied was based on pan evaporation (Eo). This experiment used a split-plot randomized complete block design; the main plot was cowpea varieties (Albina and Uno), and subplots were irrigation volume (0.75, 1.50, 2.25, and 3.0 Eo). The data were subjected to analysis of variance; then, the means were compared using Duncan’s Multiple Range Test (DMRT). All tests were considered significant at p < 0.05. The experimental results showed that the water requirement during the vegetative phase for 5 consecutive weeks for the Albina variety was 2.91 Eo, 3.0 Eo, 3.0 Eo, 3.0 Eo, and 2.11 Eo; for the Uno variety was 3.0 Eo, 3 .0 Eo, 3.0 Eo, 2.94 Eo, and 2.10 Eo, respectively. For the Albina and Uno varieties at the generative phase, the plant water requirements were 1.66 Eo and 1.79 Eo, respectively. In cowpea farming, the optimum treatment for efficient water use or lowest usage of water was determined to be 2.25 Eo of irrigation volume combined with the Albina variety. Cowpea growth and productivity are significantly impacted by irrigation volume. [ABSTRACT FROM AUTHOR]

Field experiment was conducted under rain fed condition at the College of Education school farm Akamkpa, Cross River State during the 2021 cropping season to investigate the effect of different tobacco (Nicotianatobaccum L.) leaf extract in the control of field pests in cowpea. A randomized Complete Block Design (RCBD) was used with five treatments and three replicates. Treatments (T) consist of T1 (No application), T2 (0.05kg of tobacco extract + 100g caustic in 5 liter of water, T3 (1kg tobacco extract + 100g caustic soda in 5 liter of water, T4 (1.5kg of tobacco extract + 100g of caustic soda in 5 liter of water), T5 (karate insecticide at 2.5ml/l) Growth parameters (Plant height and number of branches per plant) and yield parameters (Number of pods/plant, number of seeds/pod, 100 seeds weight and net yield) were determined. Result showed that there was significant (P<0.05) plant height and number of branches at 40 days after planting. There was significant (P<0.05) difference in number pods/plant, 100 seeds weight and net yield among the treatments. Treatment five (T5) gave the highest rate of return per naira among the treatments followed by treatment three (T3). Therefore, based on this study if tobacco extract were to be used, treatment three [(T3) 1.00 kg (tobacco extract) is recommended. [ABSTRACT FROM AUTHOR]

'California Blackeye 77' (CB77) (Reg. no. CV‐344, PI 698656) is a blackeye‐type cowpea [Vigna unguiculata (L.) Walp] cultivar developed by the University of California, Riverside. CB77 is distinguished from the industry standard cultivars, 'California Blackeye 46' (CB46) and 'California Blackeye 5' (CB5), by its ability to resist infestation caused by cowpea aphid (Aphis craccivora Koch), a destructive sap‐sucking insect pest prevalent in the Central Valley of California and warm‐to‐hot regions worldwide. CB77 was developed by introgression of two known quantitative trait loci for aphid resistance from the African cowpea breeding line IT97K‐556‐6 into CB46 through marker‐assisted backcrossing. Genotyping with 51,128 single nucleotide polymorphism markers reveals that CB77 is near‐isogenic to CB46 and carries two resistance haplotypes (∼4 Mb in total) from IT97K‐556‐6. On‐station and on‐farm trials with aphid infestations confirmed the inherent resistance in CB77 (aphids covered 0–10% of plant surface area without causing any crown damage, whereas check CB46 had aphids covering 60–70% of plant surface area and causing severe crown damage). Under protected conditions, CB77 showed grain yield, seed quality, and other agronomic characteristics equivalent to CB46 and better yield than CB5. CB77 could therefore be substituted for CB46 and CB5 in production regions where aphids are present. The near‐isogenic pair CB77 and CB46 are also useful materials for resistance gene discovery. Core Ideas: CB77 is statistically higher than the current commonly grown cultivar CB46 for aphid resistance.CB77 has seed yield and quality equivalent to or better than CB46 based on multi‐year trials.Marker data for CB77 and founder parents could be useful in fine mapping of resistance genes. [ABSTRACT FROM AUTHOR]

Cowpea [Vigna unguiculata (L.) Walp.] is a major legume crop and an important source of protein in Africa. The Kafr El-Sheikh University has a long history of cowpea breeding and improvement in Egypt. Two superior lines with high seed yield and quality were selected through mutation breeding and released to farmers as new varieties under the names Kafr El Sheikh-1 and Kaha-1. Crosses were made between these two varieties to further improve cowpea to meet farmers’ demand. Using the pedigree selection method, 13 new superior F10 lines were selected and evaluated over 2 years for seed yield and related traits, earliness, and protein content under low (16 plants/m2) and high (24 plants/m2) plant densities. The results showed that plants grown in narrower space produced significantly higher seed yield per unit area than the plants grown in wider space. All developed lines produced significantly higher seed yield than the two parental lines in the 2018 trial and Kaha-1 in the 2019 trial. Line number 6 proved to be the best genotype for earliness (73.5–73.9 days after sowing), seed yield (573–647 g/m2), and crude protein content (22.7–24.3%) in both trials. In addition, line 4 with bushy determinate growth habit and high seed quality was recently released as a new variety (Sakha-1). Several other cowpea lines have clear potential for release as new high-yielding varieties with early maturity and high seed quality for farmers in Egypt. Seeds of selected lines are available from Kafrelsheikh University. This shows that mutation breeding and pedigree selection methods are among the most promising breeding methods for cowpea improvement. [ABSTRACT FROM AUTHOR]

Hybridization programmes that potentially exploit the variability existing in the wild germplasm of Vigna unguiculata L. Walpers could be of great potential for the future of plant breeding. Bearing this in mind, four cultivated cowpea varieties (Achi shuru, Ife Brown, Kanannado and Zebra bean) were crossed to two of their wild relatives: subsp. dekindtiana var. pubescens and subsp. unguiculata var. spontanea to ascertain the cross compatibility, reproductive potential and possible heterosis in the F1 generations. Results showed that the cultivated varieties hybridized relatively well with their wild relatives showing pod set range of 42.9% to 52.3% in crosses with subsp. dekindtiana var. pubescens and 40.0% to 52.0% in crosses with subsp. unguiculata var. spontanea. The F1 hybrid plants showed high heterosis in plant height, number of leaves per plant, number of flowers per plant, number of pods per plant and percentage pod set. They also produced viable seeds for F2 generations. These results are indications of a good reproductive potential of the hybrids thus making the wild relatives, good sources of important gene pool for the improvement of the cultivated populations. [ABSTRACT FROM AUTHOR]

Cowpea is a nutrient-dense legume that significantly contributes to the population's diet in sub-Saharan Africa and other regions of the world. Improving cowpea cultivars to be more resilient to abiotic stress such as drought would be of great importance. The use of a multi-parent advanced generation intercross (MAGIC) population has been shown to be efficient in increasing the frequency of rare alleles that could be associated with important agricultural traits. In addition, drought tolerance index has been reported to be a reliable parameter for assessing crop tolerance to water-deficit conditions. Therefore, the objectives of this study were to evaluate the drought tolerance index for plant growth habit, plant maturity, flowering time, 100-seed weight, and grain yield in a MAGIC cowpea population, to conduct genome-wide association study (GWAS) and identify single nucleotide polymorphism (SNP) markers associated with the drought tolerance indices, to investigate the potential relationship existing between the significant loci associated with the drought tolerance indices, and to conduct genomic selection (GS). These analyses were performed using the existing phenotypic and genotypic data published for the MAGIC population which consisted of 305 F8 recombinant inbred lines (RILs) developed at University of California, Riverside. The results indicated that: (1) large variation in drought tolerance indices existed among the cowpea genotypes, (2) a total of 14, 18, 5, 5, and 35 SNPs were associated with plant growth habit change due to drought stress, and drought tolerance indices for maturity, flowering time, 100-seed weight, and grain yield, respectively, (3) the network-guided approach revealed clear interactions between the loci associated with the drought tolerance traits, and (4) the GS accuracy varied from low to moderate. These results could be applied to improve drought tolerance in cowpea through marker-assisted selection (MAS) and genomic selection (GS). To the best of our knowledge, this is the first report on marker loci associated with drought tolerance indices in cowpea. [ABSTRACT FROM AUTHOR]

Agricultural sustainability can be achieved through Integrated Pest Management (IPM). Integrated Pest Management (IPM) incorporates economic sustainability with environmental and social concerns. The goal of integrated pest management is to optimize profits and achieve agricultural and natural resource sustainability over the long period. This study evaluated economics of integrated pest management and pesticides use decision making process among cowpea farmers, Kaduna State, Nigeria. The study was designed specifically to provide answers to the following objectives: determine the socio-economic profiles of cowpea farmers, analyze costs and returns of cowpea production, evaluate factors influencing cowpea farmers' decision of adopting integrated pest management and pesticides use, evaluate factors influencing output of cowpea production, and determine the constraints facing cowpea farmers. Data used were from primary sources. Multi-stage sampling technique was adopted. A total sample size of 100 cowpea farmers was selected. Data were analyzed using descriptive statistics, gross margin analysis, financial analysis, principal component analysis and Heckman two-stage model which involve Probit model analysis and Ordinary Least Squares Regression Model. The result shows that 84% of cowpea farmers were less than 50 years of age. The mean age was 40 years. Also, 61% of cowpea farmers had less than 11 people as members of households. Furthermore, 88% of cowpea farmers had formal education. The farmer had average experiences in cowpea farming of 9 years. The integrated pest management techniques and pesticides use adopted by cowpea farmers include crop rotations, use of quality improved seeds, early harvest, use of resistant varieties, use of insecticides, use of pesticides sprays among others. Cowpea production was profitable enterprise. The gross margin and net income of cowpea production were 911,990 Naira and 889,090 Naira respectively. The gross margin ratio was 0.92.In first stage of the Heckman two-stage model, the statistical and significant factors influencing adoption of integrated pest management and pesticides use include age (P < 0.05),sex (P < 0.10), educational level (P < 0.01), household size (P < 0.05), extension contact (P < 0.05), and experiences in cowpea farming(P < 0.10). In the second stage, factors significantly influencing output of cowpea production were age(P < 0.10), sex(P < 0.10), educational level(P < 0.05), household size(P < 0.10), farm size(P < 0.05) and labour input(P < 0.10). Lack of improved seeds, lack of extension agents, lack of storage facilities, lack of chemical inputs and bad roads infrastructures were constraints facing cowpea farmers. The retained constraints explained 71.42% of all components included in the principal component model. The study recommends that extension agents should be employed to train farmers on integrated pest management and pesticides use, improved quality cowpea seeds should be provided and feeder roads should constructed for easy evacuation of cowpea produce to market centres. [ABSTRACT FROM AUTHOR]

Cowpea is one of the vital grain legumes used for human and animal nutrition. Due to its rich protein content, cowpea supplies the protein requirement, especially in the African continent. Although cowpea is morphologically similar to common bean, it is a more tolerant species to heat and drought conditions. So, cowpea production has various advantages in semi-arid regions. The aim of this study was to determine some agronomic traits of used cowpea genotypes and evaluate their correlations with yield components. Plant height (PH), stem diameter (SD), leaf surface temperature (LST), total chlorophyll content (TCC), number of pods per plant (NP), number of seeds per plant (NS) and seed yield (SY) changed between 54.6-91.3 cm, 3.1-7.6 mm, 27.9-31.7 °C, 39-56.1%, 25.7-49.1, 307.5-684 and 646-2381 kg ha-, respectively. It is noteworthy that Karagöz produced the maximum SY compared to the other varieties. Besides, it was determined that SY has positive significant correlation with NS (r=0.98**), NP (r=0.96**), TCC (r=0.93**), SD (r=0.91**) and PH (r=0.86**). [ABSTRACT FROM AUTHOR]

Information on combining ability and reciprocal effects (REC) facilitates efficient utilization of genetic materials in a breeding program. This study was conducted (at the CSIR-Savanna Agricultural Research Institute, Ghana) to determine general combining ability (GCA) and specific combining ability (SCA), heritability, genetic advance, GCA, and SCA effects as well as the relationship between parents per se performance and progenies for yield components and maturity traits in cowpea. The test populations were derived using a 5 × 5 complete diallel cross of parents with different yield attributes and maturity durations. The results indicated that GCA was predominant for number of days to 90% pod maturity, plant height at maturity, and hundred-seed weight. This showed that genes with additive effects conditioned these traits. Padi-Tuya, Songotra, and IT86D-610 were identified as good general combiners for grain yield, while Sanzi-Nya was identified as a general combiner for developing extra-early duration cowpea varieties. Crosses Songotra × Sanzi-Nya, SARC-1-57-2 × IT86D-610, Songotra × SARC-1-57-2, and Padi-Tuya × Songotra were identified as good specific combiners for days to 50% flowering, pod length, pods per plant, pod yield, grain yield, and seeds per pod. The findings from this study provide useful information on the inheritance of early maturity and yield traits in cowpea. This can be exploited to develop high yielding and early maturing cowpea varieties as climate smart strategy to mitigate climate change via breeding methods such as pedigree selection and marker assisted backcrossing (MABC). Pedigree selection method is being used to develop varieties from the hybrid with high and significant SCA for grain yield, whereas the development of extra-early duration varieties via MABC with Sanzi-Nya (general combiner for earliness traits) as a donor parent is ongoing. [ABSTRACT FROM AUTHOR]

The limitation of soil amendments and insufficient and irregular rainfall are the main factors accounting for the decline in crop yields in the Sahelian low-input cropping systems. This study explored the agronomic and economic responses of integrated use of millet glume-derived compost with synthetic fertilizer in cowpea-based cropping system. A two-year field experiment was laid out as factorial design arranged in randomized complete blocks with three rates of compost (0, 4000, and 8000 kg ha−1) and three rates of recommended synthetic fertilizer (0, 50, and 100%). Cowpea grain yield increased markedly with combined application of compost and synthetic fertilizer. The combined use of compost applied at 8000 kg ha−1 and 50% of the recommended rate of synthetic fertilizer increased cowpea grain yield by 51% compared to the application of 100% of the recommended rate of synthetic fertilizer. The rainwater use efficiency (RaUE) increased by 52 and 49% with the combined application of compost at 8000 kg ha−1 along with 50% of the recommended rate of synthetic fertilizer when compared to the application of 100% of the recommended rate of synthetic fertilizer in 2013 and 2014, respectively. All treatments induced a positive net income, and the highest value/cost ratio was achieved with combined application of compost and synthetic fertilizer. This study highlights the possibility of improving cowpea productivity through combined use of composted locally available organic input with half of the recommended rate of synthetic fertilizer. This combination would reduce the investment in mineral fertilizer currently made by smallholder farmers in the Sahelian low-input cowpea cropping system and reduce environmental pollution resulting from the current practice of burning the millet glume. [ABSTRACT FROM AUTHOR]

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An experiment was carried out to investigate the response of two different varieties of Cowpea i.e. Kashi Unnati and Kashi Kanchan to different concentrations of Naphthalene Acetic Acid (NAA) i.e. 10, 20 and 30ppm. These concentrations of NAA were evaluated for physiological efficacy in factorial randomized design with five replications each. Physiological parameters such as germination percentage, shoot, root length, seedling length and seedling vigour index as well as yield parameters such as No. of pods/ plant, No. of seeds/ plant, 1000 seed weight and seed yield/ plant were studied during the present investigation. Each concentration of NAA showed positive effect on all the growth parameters studied, the effect of 30 ppm concentration remained greater on both varieties. However, variety Kashi Kanchan had an edge over Kashi Unnati. [ABSTRACT FROM AUTHOR]

Gamma - ray technique, as physical mutagens method, substitute classical breeding methods, for development a new varieties, to face of population explosion threats, and limited of agricultural production elements (water + agricultural area). Cowpea seeds cv. Kafr El-- Shiekh, were exposed by six γ - doses "γ d"; 0, 50,100, 150, 250 and 350 Gray (Gy). Pretreated seeds were germinated to predicted lethal dose (LD50) and observed germination scenarios. Thereafter, exposed seeds by 0, 50, 100 and 150Gy., were grown till maturity at open field to evaluate growth characterizes i.e., leaf area index "LAI", specific leaf weight "SLW" net assimilation rate "NAR", and relative growth rate "RGR" As well as, nodules number per plant "NNP", nodules dry mass per plant "NDM", and seed yield "Sy", using complete randomized block design. Results affirmed that LD50 was ≈ 200 Gy. Gamma ray has a bio-positive significant effect on germination indices. Where, max. germination percentage "GP" (92%), mean germination time "MGT"(1.87day), highest mean daily germination "MDG" (30.67z% day -1 ), and germination index "GI" (380) were obtained by exposed seeds with 150Gy. Also, the development of the growth parameters LAI, SLW, NAR, RGR, affected significantly (P ≤ 0.05) by γd from plant establishment to maturity. NNP had direct relations with γd, at different plant age. Then, the increase in "Sy" was more pronounced and significantly affect with pre-sowing seeds irradiation, compared with control. [ABSTRACT FROM AUTHOR]

Core Ideas: Soybean, cowpea, and lablab leaves differed in nutritive value.Soybean and cowpea grain yield responded differently to leaf harvesting done at Vegetative Stage 6 (V6).Legume plants from which two leaves (66%) are harvested at V6 may have similar grain yield to those whose leaves are not harvested. Grain legumes can thrive in adverse environments, making them a climate‐smart technology for hunger mitigation. Although several countries rely immensely on grain legumes to meet daily protein intake requirements per capita, the potentiality of leaf utilization for protein and other nutrients has not been widely considered; additionally, insufficient information is available on leaf removal effects on yield and leaf nutritional composition of grain legumes. A 2‐yr experiment was conducted in central Iowa, USA, to determine the effects of leaf removal rates on nutritive value of removed leaf tissue and subsequent grain yield of cowpea [Vigna unguiculata (L.) Walp.], lablab [Lablab purpureus (L.) Sweet], and soybean [Glycine max (L.) Merr.]. Across entries, dry leaf mean nutrient concentration was 229 g kg–1 for CP, and 17,832, 4461, 21,991, 3702, 113, 205, and 86 mg kg–1 for Ca, Mg, K, P, Mn, Fe, and Zn, respectively. Yield and major yield attributes were affected by leaf removal rate in 2014, but not in 2013. In 2014, grain legumes with 0% leaf removal had 20, 32, and 35% greater yield and seeds weighed 6, 11, and 12% more than those with 33, 66, and 99% leaf removal, respectively. Aboveground biomass, yield, and yield components also differed among entries both years. Grain legume leaf utilization as vegetable or forage may improve human and ruminant nutrition by using leaves, especially in developing countries. [ABSTRACT FROM AUTHOR]

Stability in yields of agronomically acceptable cultivars is generally regarded as the ultimate goal in cowpea improvement. Nine advanced cowpea lines and 3 local checks were evaluated for grain yield in eastern Kenya with the aim of identifying stable genotypes and integrating farmer preferences. The study was conducted in 3 locations over 2 years under a randomized complete block design with 3 replications. Stability was estimated using additive main effects and multiplicative interaction (AMMI) and genotype by environment (GGE) models. There was variation among genotypes, locations and their interactions for grain yield. Genotype G5, G9 and G2 were found to be stable and high yielding. Environments Kit16 and Kit15 were considered as the most suitable for selecting superior genotypes for adaptability and stability. Farmers' criteria for selecting genotypes included early maturing, pod length, disease tolerant and high yielding varieties. Cowpea performance for grain yield was greatly influenced by inherent genotypic factors, environment and their interaction effects. [ABSTRACT FROM AUTHOR]

This study was designed to analyze the profitability of cowpea production in Mubi South Local Government Area of Adamawa state. The primary data were collected through the use of structured questionnaires. Purposive and simple random sampling techniques were used for the selection of a study area. Descriptive statistics and inferential techniques were used as analytical tools. The result shows that most of the cowpea producers (64%) were aged between 20-49 years with males dominating the business and the majority of the respondents (57%) were married. Household size was relatively large, 78% had some form of formal education and a greater proportion of the respondents (86%) did not belong to any farmer's association. Most of the respondents (61%) are full-time farmers, while about 92% of cowpea farmers had between 6 - >15 years of experience in cowpea production. Most of the farmers (78%) had one form of formal education. The computed gross margin and net farm income were N289128.2/ha (=816.5USD) and N286976.3/ha (=810.4USD), respectively, for cowpea production, which indicated that cowpea production was profitable in the area. It is recommended that, there is need for government support in terms of revitalization and priority finding extension delivery activities and agricultural development programs (ADP) in the study and area, access to subsidized farm input (such as pesticide, fertilizer and herbicide) and making credit facilities accessible and affordable to enable farmers boost their production. [ABSTRACT FROM AUTHOR]

Organic seed is the basic for organic agriculture, since it is a crucial link in the chain from research, breeding, seed production, to organic production. With organic seeds the grower can complete the chain of organic input. To develop an organic foliar spray technique and for organic seed production, experiments were carried out to study the effect of organic foliar spray with pulse sprout extract on rice. In this study, horse gram and cowpea, the unexploited legumes of the tropics with high nutritional quality and comparatively low cost were used for preparing the pulse sprout extracts, an organic foliar spraying material. Higher accumulation of bioactive substances in sprouted seeds offers immense scope to develop an inexpensive and effective organic foliar spray technology so as to achieve better crop growth and higher seed yield of rice, the major staple food of the world. The biochemical analysis was done in both extracts to estimate the total antioxidants activity, soluble protein content, total soluble sugars, ascorbic acid content and minerals like nitrogen, phosphorus, potassium, calcium, iron and zinc. Subsequently, the effect of pulse sprout extract spray in improving crop growth, tillering, productivity, and resultant seed quality of was studied by spraying on the parental lines of rice hybrid CORH3 (A, B and R lines) and rice variety CR 1009. The experiment consisted of four trials. In the first trial, four concentrations of pulse extract (1, 2, 3, and 4%) were evaluated in the R line (medium duration variety) of CORH3 (medium duration). In the subsequent trials, the best concentrations (2 and 3% for horse gram and 1 and 2% for cowpea), determined from the first trial, were evaluated again in two medium duration lines of B line multiplication (AXB) and hybrid seed production (AxR). The fourth trial was done with a long duration variety namely CR 1009. Spraying of pulse sprout extract significantly improved majority of the growth and yield attributes culminating in significantly higher seed yield, in all the four trials. The study firmly revealed foliar sprays with either 3% horse gram sprout extracts or 2% cow pea sprout extract during active tillering and seed filling stages of rice crop, can significantly increase the growth and yield attributes, eventually resulting in higher seed yield, irrespective of the cultivars. It could be concluded that foliar spraying of 3% horse gram sprout extract or 2% cow pea sprout extract at active tillering stage and seed filling enhances seed yield attributes and yield in rice. [ABSTRACT FROM AUTHOR]

An improved cowpea transformation method utilizing Agrobacterium -mediated gene delivery to explants derived from the cotyledonary nodes of imbibed cowpea seed is described. The explants were regenerated following a sonication procedure and a stringent selection comprising alternating regimes of kanamycin and geneticin. The method was reproducible and led to the recovery of independent fertile transgenic plants in the greenhouse at a level of about one per cent of starting explants. A transgene encoding an insecticidal protein from Bacillus thuringiensis was used to demonstrate the efficacy of the system. [ABSTRACT FROM AUTHOR]

Highlights • Key traits that explain variation in field-grown cowpea genotypes are presented. • Root biomass-, tissue angle- and diameter-related traits contributed most to genotypic variation. • Root biomass correlated positively with count-, length- and diameter-related traits. • Soil and root tissue angles were positively correlated with each other. • Positive correlations among traits suggests multi-trait improvements are possible. Abstract Cowpea is a grain legume that is grown extensively as an alternate protein and income source for many smallholder farmers. Characterising cowpea root phenotypes could provide the basis for developing genotypes with root system architecture (RSA) traits that increase soil resource acquisition. Measuring RSA traits of any field crop is a demanding task, in terms of expediency, time, cost, and competence. Targeted root phenotyping strategies focusing on a few relevant traits might aid in side-stepping some of the challenges associated with phenotyping roots of field crops. The objectives of this study were to (i) measure genotypic variation for RSA and shoot traits of cowpea genotypes; and (ii) identify candidate variables and genotypes that contribute the largest share of variance. Sixty cowpea accession were grown in field trials at the University of Cape Coast, Ghana. Seventy variables, mostly quantitative RSA traits were measured. Multivariate analysis was used to determine major traits contributing to variation. There were significant differences (P < 0.05) for the majority of traits evaluated. Fifty-nine traits had coefficients of variation of ≥0.3 among genotypes and were selected for further examination. Broad-sense heritability (H2) estimates were generally intermediate to high and ranged from 0.11 to 0.96. The Shannon-Weaver diversity index (H') was variable among traits and ranged from 0.00 to 0.88. Shoot and root biomass correlated closely and positively with count- and length- and diameter-related traits. Cluster analysis identified three homogeneous genotype groups and identified groups of cowpea genotypes that could be exploited in breeding programs to improve the genetic basis of root traits. The first nine principal components explained over 74% of total genotypic variation for the twenty-nine traits included in the PCA. Sixteen traits contributed more than other traits to the variability in PC1 and PC2. Soil and root tissue angle-related traits, shoot and root diameter-related traits, root biomass, hypocotyl root length, root count and lateral root density -related traits were among the top 50% of the most important traits contributing to variation and thus warrant consideration in efforts to breed for improved genotypes in cowpea. The workflow presented offers a robust, cost-effective and simple approach to identifying focal root traits that contribute to diversity in grain legumes. The results could potentially facilitate the characterization of specific traits suitable for targeted genotype selection and breeding of new cowpea varieties for efficient RSAs. [ABSTRACT FROM AUTHOR]

TWO FIELD experiments were established in middle Nile Delta alluvial soils. The study was conducted on the two successive summer seasons of 2016 and 2017 in the experimental farm of Tag El-Ezz Agricultural Research Station, Agricultural Research Center (ARC), Dakahlia Governorate, Egypt. The experiment was laid out in a split plot design with three replications, assigning nine treatments to study the effect of three forms of organic fertilization (without, farmyard manure and compost rice straw) as main plot, and 3 forms of foliar application (control, mix of micro nutrients (Fe, Zn and Mn) and humic acid (HA)) as sub plot on growth, yield and chemical constituents of cowpea (Vigna unguiculata L.). The obtained results showed that, addition of organic amendments in forms of compost rice straw significantly increased plant growth parameters (plant height, fresh weight, dry weight and number of leaves), chemical composition of leaves (chlorophyll a, b and total chlorophyll content, N, P, K, Fe, Zn and Mn as well as quality parameters (C. protein, T. carbohydrates, C. fiber, ash and total sugar of cowpea seeds except with moisture conetnt) and yield as well as its components (No. of pods/plant, No. of seed/pod, 100 seed weight and seed yield, also availability of soil (N, P and K). On the other hand; mix of micro elements gave significant positive effect and higher average values for all parameters previously. The interaction effect between organic fertilization and foliar application show a primitive effect on all parameters and the highest mean values of parameters was recorded with using CRS as organic fertilization and mix of micro nutrients as foliar application. [ABSTRACT FROM AUTHOR]

Cowpea (Vigna unguiculata L. Walp) is an affordable source of protein and strategic legume crop for food security in Africa and other developing regions; however, damage from infection by root-knot nematodes (RKN) suppresses cowpea yield. The deployment through breeding of resistance gene Rk in cowpea cultivars has provided protection to cowpea growers worldwide for many years. However, occurrence of more aggressive nematode isolates threatens the effectiveness of this monogenic resistance. A cowpea germplasm collection of 48 genotypes representing the cowpea gene-pool from Eastern and Southern Africa (cowpea has two major pools of genetic resources - Western Africa and Eastern/Southern Africa) was screened in replicated experiments under field, greenhouse and controlled-growth conditions to identify resistance to RKN, to determine the spectrum of resistance to RKN, the relative virulence (VI) among RKN species and isolates, and the relationship between root-galling (RG) and egg-mass production (EM). Analysis of variance of data for RG and EM per root system identified seven genotypes with broad-based resistance to Meloidogyne javanica (Mj), avirulent (Avr-Mi), and virulent (Mi) M. incognita isolates. Two of the 48 genotypes exhibited specific resistance to both Mi isolates. Most of the genotypes were resistant to Avr-Mi indicating predominance of Rk gene in the collection. Based on RG data, both Mj (VI = 50%) and Mi (VI = 42%) were fourfold more virulent than Avr-Mi (VI = 12%). Resistant genotypes had more effective resistance than the Rk-based resistance in cowpea genotype CB46 against Mj and Mi. Root-galling was correlated across isolates (Avr-Mi/Mj: r = 0.72; Mi/Mj: r = 0.98), and RG was correlated with EM (r = 0.60), indicating resistance to RG and EM is under control by the same genetic factors. These new sources of resistance identified in cowpea gene-pool two provide valuable target traits for breeders to improve cowpea production on RKN-infested fields. [ABSTRACT FROM AUTHOR]

Future increase in drought and heat stress will challenge legume productivity in many regions. In Sub-Saharan Africa, legumes are earmarked as an integral component in building resilience to climate change and food security in smallholder farming systems. Hence, the need for continuous screening of drought tolerant legume genotypes for sustained productivity. A 2-yr field study was conducted to identify superior cowpea genotypes with high biological nitrogen fixation (BNF), grain yield, and drought tolerance. Four genotypes, selected from a pool of 91, were grown under four moisture levels ranging from wellwatered (WW) to severe water stress (SS). Grain yield, shoot biomass, nodule mass, and BNF were determined. There was significant effect of water stress on the measured parameters. Nodule mass and BNF were more sensitive to water stress compared to shoot biomass across genotypes. Water stress resulted in 80% reduction in nodule biomass between WW and SS. As a result, cowpea genotypes grown under SS conditions fixed 57% less N2 compared to those under WW. The study also revealed significant genotypic variation in shoot biomass, grain yield, and BNF. Genotype TVu4607 was low in grain yield but performed better for BNF (71 kg N ha-1 under WW and 30 kg N ha-1 under SS). Genotype IT00K-1263, proved to be our superior genotype with a good balance of biomass, BNF and grain yield. Our findings suggest that future water stress may significantly affect cowpea productivity, mostly its capacity to fix nitrogen. Consequently, adaptation strategies to improve drought resistance in cowpea are needed, particularly improvement of BNF under water stress. [ABSTRACT FROM AUTHOR]

In order to study the effects of desert dust on yield and yield components of cowpea, two field experiments were conducted in the factorial layout based on randomized complete block design with three replicates in Dezful and Mashhad, Iran in 2015. The experimental treatments were combinations of desert dust in three levels (0, 500 and 1500 µg m−3), numbers of desert dust application (once, twice and thrice) and two types of desert dust. The desert-dust particles were collected during dust storms occurred in Dezful and Zabol, which are the main sources of dust in Iran. The results showed that the biological yield and the grain yield were significantly decreased in both studied sites (Dezful and Mashhad) when the plants exposed to 500 µg m−3 desert dust treatment compared to normal conditions. Total soluble sugar and proline contents in plant leaf tissues increased significantly when they affected by 1500 µg m−3 of desert dust, while the plant height was significantly decreased by increasing the desert-dust concentrations at both sites. Biological yield, grain yield, and 100-seed weight were also significantly affected by the desert dust. Overall, the desert dust has adverse effects on yield of cowpea. [ABSTRACT FROM AUTHOR]

Abstract: Using phosphate fertilizer (particularly at high levels) to improve the phosphorus (P) level of soils during the cultivation of legumes and other cereals unfortunately has negative effect on the levels of micronutrients like zinc (Zn) in grains. This study evaluated the influence of P and nitrogen (N) fertilization on iron (Fe) and Zn levels of cowpea grains. Cowpea genotypes B301, TVu 16514, IT90K‐205‐8, UAM09‐1046‐6‐1 and TVu 1272 were grown in greenhouse pots containing barren soils (to simulate micronutrient‐deficient soils) in two stages of varied P (0, 20, 40, and 60 kg P ha−1) with and without N (i.e. P only and P v N). The effect of these interactions on Fe and Zn levels were measured. Application of P alone showed no significant (p > 0.05) negative influence on Zn and Fe content of the grains. However, a combination of N and P fertilization reduced Zn content significantly at 60P (p < 0.05). Further evaluation showed TVu 1272 as highest in terms of Fe and Zn at all P levels. Significant reduction of grain Zn was found at 60P on N and P interaction. No such negative correlation was observed for Fe. TVu 1272 (a high‐yielding genotype) is recommended as a source of high micronutrient. [ABSTRACT FROM AUTHOR]

Climatic changes and increasing climatic variability’s are likely to aggravate the problems of future food security by exerting pressure on agriculture. A field experiment was conducted with Cowpea (Vigna unguiculata) to assess the impact of increased temperature in polyhouse with three different treatment’s viz; 100% organic, 100% inorganic, and 50% organic + 50% inorganic nutrient management on growth, yield and carbon dioxide (CO2) evolution compared to that of open natural condition. The results showed that crop production declined with increase in temperature and the mean root and shoot weight were higher in the case of open cultivated plants over the polyhouse cultivated plants. In the case of nutrient management practices, the maximum yield was with 100% application of inorganic fertilizers under open cultivated conditions whereas under polyhouse conditions, higher yield was obtained with 100% application of organic manures. Among the different treatments applied, 100% application of organic manure resulted in maximum carbon dioxide emission in open conditions with 654 mg, whereas polyhouse showed 316 mg only. The lowest value of CO2 evolution of 277 mg was observed with 50% of organic manure + 50% of inorganic fertilizer’s application of fertilizers under open conditions. In all the three nutrient management treatments, the CO2 evolution (mg) reached plateau and stabilized over the last two observations. At the last interval, CO2 evolution had the values from 4.00 to 6.80 mg of CO2 in all the treatments. Cumulative CO2 evolution (mg) showed that the emission was higher under open natural conditions when compared to the polyhouse conditions at elevated temperature and this indicated that the microbial respiration was higher under natural conditions. Ambient air temperature and soil temperature was higher under polyhouse conditions than that of open natural conditions. However, soil moisture was higher under open conditions than the polyhouse conditions in most of the observations. Based on the studied parameters, it is suggested that enough mitigation strategies need to be adopted for sustaining the crop production under changing climatic scenario. [ABSTRACT FROM AUTHOR]

This work was carried out during the two autumn seasons of 2015 and 2016 at Ghazala Experimental Farm, Fac. Agric., Zagazig University to study the effect of mineral nitrogen fertilizer levels (15, 25 and 35 kgN/fad.) and lithovit levels (0, 2, 4 and 6 g/l) as well as the interaction between them on growth, seed yield and anatomical traits of cowpea plants grown in clay soil. Fertilizing cowpea plants with mineral N at 35 kg/fad., increased plant height and number of both leaves and branches/plant, total dry weight/plant, as well as seed yield/fad., and N, P, K, total carbohydrates and total protein in seeds. Whereas N at 25 kg/fad., increased dry weight of leaves and branches/plant as well as N,P and K uptake in leaves and branches compated with low used level of 15 kg N/ faddan. Spraying cowpea plants with lithovit at 6g/l induced all previous characters as well as N, P and K uptake in leaves and branches. The interaction between N at 25 kg/fad., and lithovit at 6 g/l increased plant height, number of both leaves and branches/plant, total dry weight/plant, N,P and K uptake by leaves and branches, seed yield/fad., and N, P, K total protein in seeds. As for the effect of N levels and foliar application with lithovit on anatomical structure of vegetative organs of cowpea, it could be stated that 25 kg mineral nitrogen appeared a decrease in the main stem diameter, thickness of cortex, fiber, phloem, xylem and pith diameter, number of vascular bundle and diameter of vessel compared with high level of 35 kg N/fad., whereas the same level of N and lithovit at 6 g/l showed an increase in all previous characters except fiber thickness. Application of 25 kg mineral N/fad., caused in reduction in midvein, lamina of leaflet blades, palisade and spongy tissue thickness and dimensions of midvein bundle compared with high level of 35 kg N/fad., but the same level of N and lithovit reflected an increase in thickness of midvein region, width of midvein bundle, number of vessels/ midvein bundle and average diameter of vessel, but decreased the thickness of leaf lamina. [ABSTRACT FROM AUTHOR]

In tropical and semi-arid regions of Brazil, phosphorus is one of the most limiting elements of cowpea productivity. The aim of this study was to assess the effects of applying five phosphorus doses in the soil on morpho-physiological and production components in three improved cultivars of cowpea. The experiment was carried out at the São Fernando farm located in José de Freitas, PI, Brazil, in a Plinthosol with a low phosphorus content. The experimental design was complete randomized block design with four replications in a 5 × 3 factorial scheme consisting of five phosphorus doses (0, 60, 120, 180, and 240 kg P2O5 ha-1) and three improved cowpea cultivars (BRS Guariba, BRS Tumucumaque, and BRS Cauamé). No interaction was observed between cultivars and phosphorus doses for any of the assessed variables. The cultivar BRS Tumucumaque showed the highest value for one-hundred-grain weight (21.0 g) and, together with BRS Guariba, the highest value of pod length. An increment was observed in growth (stem diameter, main branch length, leaf area, and shoot dry matter) and production characteristics (number of pods per plant, number of grains per pod, one-hundred-grain weight, and grain production per plant) in response to increases in phosphorus doses. The dose of 183.1 kg P2O5 ha-1 provided the maximum technical grain yield, estimated at 2,023.3 kg ha-1. [ABSTRACT FROM AUTHOR]

With the objective to assess the fresh biomass and dry matter accumulation per plant in cowpea - sorghum intercropping, a field experiment was carried out in the farm of self-consumption "Día y Noche", at the Basic Unit of Cooperative Production "28 de Octubre", Santa Clara municipality, Villa Clara province, Cuba, on a Cambisol soil. The two spatial arrangements consisted on one sorghum row and two cowpea rows; one sorghum row and three cowpea rows. Also, the respective cowpea and sorghum monocultures were evaluated. For determining fresh biomass and dry matter accumulation per plant, 15 plants per treatment were harvested. The maximum values in fresh biomass and dry matter accumulation were observed in one sorghum row and two cowpea, and sorghum monoculture treatments, with 227 g, 47 g for cowpea and 241.4 g, 110 g for sorghum respectively. [ABSTRACT FROM AUTHOR]

Zinc is an essential element in biological systems, which is required in small quantities. The objective was to know the effect of the foliar application of the doses of 0, 7, 14 and 28 mM L-1 of chelate (Zn-EDTA) and zinc sulfate (ZnSO4) in the yield and mineral content of cowpea (Vigna unguiculata L.). In plants were counted the days to flowering, weight of grain, number of pods and number of grains per plant, in addition to the weight of 100 grains, while in the grains the content of total crude protein, nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, boron, manganese, copper and molybdenum was determined. With the doses of 7, 14 and 28 mM L-1 of Zn-EDTA the yield of grain per plant with respect to the control was increased by 53.29, 41.58 and 38.42%, respectively, while with the same doses of ZnSO4 the increase it was 27.80, 32.09 and 16.83%, respectively. The highest contents of nitrogen, crude protein, phosphorus, potassium, calcium, iron, manganese and copper were obtained with the doses of 7 and 14 mM L-1 of ZnEDTA. While the highest levels of zinc, boron, molybdenum and magnesium were found with the doses of ZnSO4, it was observed that the zinc content increases proportionally with the increase in the dose. The addition of different doses of Zn-EDTA and ZnSO4 for the biofortification of cowpea beans has an effect on grain yield, crude protein content and mineral content. [ABSTRACT FROM AUTHOR]

Zinc (Zn) is an essential trace element for plants, animals and humans; consequently, their deficiency affects their growth and development. It is estimated that between 15 and 30% of the human population in the world exhibit Zn deficiencies. The objective was to study the effect of biofortification with Zn2+ on the mineral content and yield of cowpea beans. The experiment was developed under a completely random design in two production cycles. The Zn was applied as zinc sulphate (T1: 0 µM L-1 , T2: 25 µM L-1 , T3: 50 µM L-1 and T4: 100 µM L-1 ) and as zinc chelate (T5: 0 µM L-1 , T6: 25 µM L-1 , T7: 50 µM L-1 and T8: 100 µM L-1 ). The applications of 25 μM L-1 of ZnSO4 and 50 μM L-1 of Zn-EDTA for both production cycles were the most effective in increasing the content of this element in the bean seed cowpea, determining 1.14 and 0.93 times more zinc respectively, compared to the control. The yield, in cycle 1, was decreased by 53.8 and 20.3% by applying 50 μM L-1 of ZnSO4 and 25 μM L-1 of Zn-EDTA, respectively. The addition of 50 μM L-1 of ZnSO4 and 25 μM L-1 of Zn-EDTA, in cycle 2, increased the yield by 16.7 and 37.3%, respectively, compared to the control. The best treatments to biofortify cowpea beans were 25 μM L -1 of ZnSO4 and 50 μM L-1 of Zn-EDTA for both production cycles. [ABSTRACT FROM AUTHOR]

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Cowpea (Vigna unguiculata Walp.) is increasingly planted as a second season crop after soybean [Glycine max (L.) Merr.] in the Brazilian Cerrado region. Experiments were conducted at Sinop and Primavera do Leste in Mato Grosso State to investigate the impact of cowpea inoculation with recommended rhizobium strains on biological nitrogen fixation (BNF) and grain yield. Plants were either non-inoculated, with or without 70 kg N fertilizer ha-1, or inoculated with five rhizobium strains, separately or as a mixture. Nodulation and shoot dry matter (DM) were evaluated at 35 d after emergence (DAE). Dry matter and N accumulation were evaluated and BNF contributions quantified using 15N natural abundance at 50 DAE. Nodule number and dry weight were high regardless of inoculation treatment. However, several of the inoculation treatments at Sinop and Primavera do Leste promoted significant increases in total N at 50 DAE. At both sites, the 15N abundance results indicated that inoculation significantly increased BNF contributions from 36 to 64 kg ha-1 at Sinop and from 48 to 75 kg N ha-1 at Primavera. Grain yield was significantly increased from approximately 1200 to 1500 kg ha-1 by strains BR 3262 and INPA 03-11B at the Primavera do Leste, and from approximately 850 to 1400 kg ha-1 by strain BR 3262 at Sinop. The results indicate inoculation of cowpea with elite rhizobium strains can increase BNF contributions and grain yields in the Brazilian Cerrado region, even when there are abundant populations of soybean rhizobium present in the soil. [ABSTRACT FROM AUTHOR]

Purpose The pollution of agricultural land by crude oil is a wide spread phenomenon in petroleum producing countries of the world. Therefore, there is the need to find effective and eco-friendly means of mitigating the toxic effect of crude oil on crop plants. Methods Green house experiment was conducted with cowpea seeds planted in polybags containing crude oil contaminated soil and similar concentrations treated with known amount of abattoir wastewater. The effect of abattoir wastewater (AWW) treatment of the crude oil contaminated soil on the metabolic and antioxidant properties of the leaves of cowpea seedlings was investigated. The concentrations of total sugar, total protein, total amino acid and μ-carotene, chlorophyll, starch metabolizing enzymes as well as oxidative stress markers, lipid peroxidation, catalase, xanthine oxidase, aldehyde oxidase and superoxide dismutase were determined using standard methods. Results Treatment of the crude oil contaminated soil with AWW resulted in decreases in total sugar, total protein and total amino acid as well as increase in the activities of both a-amylase and starch phosphorylase and total chlorophyll and β-carotene levels compared with those in crude oil alone treated groups. Treatment of the crude oil contaminated soil with AWW also significantly decreased lipid peroxidation and Cu/ZnSOD, but increased MnSOD, catalase, xanthine oxidase and aldehyde oxidase activities. Conclusion These observations suggest that abattoir wastewater has the ability to remediate the adverse effects of crude oil polluted soil on cowpea seedlings. Therefore, abattoir wastewater should be harnessed and used in treating crude oil polluted farmland so as to reduce its toxicity on crop plants. [ABSTRACT FROM AUTHOR]

Environmental stresses are increasing over time adversely affecting crop productivity. To face these stresses, plants adopt endogenous mechanisms, but they are not enough in most cases. Therefore, the effect of exogenous application of proline, silicon (Si) or methionine on growth and yield criteria, leaf physio-biochemical properties and leaf anatomical structure of cowpea plants grown under three levels of water deficit (W 0 ; 60, W 1 ; 40 and W 2 ; 20% of soil water holding capacity) was investigated. The water level W 0 was adequate to optimum cowpea plant growth and specified as a control. Results obtained indicated that growth criteria (i.e., shoot dry weight, plant height, leaf area and number of branches per plant), yield characteristics (i.e., dry seed weight and biological yield per plant, and 100-seed weight), contents of leaf chlorophylls a and b , total carotenoids, shoot and seed nutrients (i.e., N, P and K), and leaf relative water content and membrane stability index were significantly decreased, while activity of leaf antioxidant enzymes such as peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT), content of leaf proline and electrolyte leakage, and shoot Si were significantly increased under water deficit stress (W 1 and W 2 ) conditions compared to the control (W 0 ). However under water deficit stress, foliar application of proline, Si or methionine seemed to overcome the harmful effects of water deficit stress, at varying degrees, on the abovementioned cowpea plants characters, which were improved, compared to the corresponding controls. The Si was the most helpful one, where it increased growth criteria (i.e., shoot dry weight, plant height, leaf area and number of branches per plant), yield characteristics (i.e., dry seed weight and biological yield per plant, and 100-seed weight), contents of leaf chlorophylls a and b , total carotenoids, shoot and seed nutrients (i.e., N, P and K), and leaf relative water content and membrane stability index, and further increased shoot Si content and leaf antioxidant enzyme activities of cowpea plants compared to those of either proline or methionine application. For leaf anatomical features, the width of midvein and xylem, and the thickness of midvein, phloem and xylem tissues, and palisade and spongy tissues of leaf blade were decreased with increasing the water deficit stress; however, foliar spray of Si improved all histological features compared to those of untreated plants. [ABSTRACT FROM AUTHOR]

Cowpea is one of the most important food and forage legumes in drier regions of the tropics and subtropics. However, cowpea yield worldwide is markedly below the known potential due to abiotic and biotic stresses, including parasitism by root-knot nematodes (Meloidogyne spp., RKN). Two resistance genes with dominant effect, Rk and Rk2, have been reported to provide resistance against RKN in cowpea. Despite their description and use in breeding for resistance to RKN and particularly genetic mapping of the Rk locus, the exact genes conferring resistance to RKN remain unknown. In the present work, QTL mapping using recombinant inbred line (RIL) population 524B x IT84S-2049 segregating for a newly mapped locus and analysis of the transcriptome changes in two cowpea near-isogenic lines (NIL) were used to identify candidate genes for Rk and the newly mapped locus. A major QTL, designated QRk-vu9.1, associated with resistance to Meloidogyne javanica reproduction, was detected and mapped on linkage group LG9 at position 13.37 cM using egg production data. Transcriptome analysis on resistant and susceptible NILs 3 and 9 days after inoculation revealed up-regulation of 109 and 98 genes and down-regulation of 110 and 89 genes, respectively, out of 19,922 unique genes mapped to the common bean reference genome. Among the differentially expressed genes, four and nine genes were found within the QRk-vu9.1 and QRk-vu11.1 QTL intervals, respectively. Six of these genes belong to the TIR-NBS-LRR family of resistance genes and three were upregulated at one or more time-points. Quantitative RT-PCR validated gene expression to be positively correlated with RNA-seq expression pattern for eight genes. Future functional analysis of these cowpea genes will enhance our understanding of Rk-mediated resistance and identify the specific gene responsible for the resistance. [ABSTRACT FROM AUTHOR]

A pot experiment was conducted to investigate the role of methyl jasmonate (MeJA) in alleviation of the adverse effects of salinity on cowpea. Seeds were soaked in 0, 25 and 50 μM MeJA for 20 h and then the seedlings were irrigated with different concentrations of NaCl (0, 50 and 100 mM). Salt stress markedly decreased growth attributes namely shoot length, shoot and root dry weight and leaf area. NaCl stress also significantly reduced chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins and relative water content (RWC). Furthermore, salinity noticeably increased proline and total soluble sugars content. Nonetheless, seeds treatment with MeJA especially 50 μM, improved the growth of cowpea plants by increasing chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins, proline accumulation, total soluble sugars and RWC under salt stress conditions. Thus results indicate that pretreatment of seeds with MeJA could be used as an effective technique for improving cowpea plants tolerance to salt stress. [ABSTRACT FROM AUTHOR]

Moisture stress is an important factor affecting field-grown cowpea in the tropics, especially in the dry seasons, and irrigation is required for successful yields. Field experiment was conducted at Teaching and Research Farm of the Department of Agricultural Engineering, Federal University of Technology, Akure, during 2014 growing season using a completely confounded design with four replicates to evaluate the impact of soil moisture stress on the yields of cowpea under four different irrigation treatments. The treatments were 100%, 80%, 60% and 40% Full Irrigation Treatment (FIT). Soil moisture contents were determined biweekly using gravimetric method. Cowpea grain and biomass yields were measured after harvest. The yield response factor (Ky) was determined to evaluate the plant response to irrigation. The point where Ky and the ratio ratio of yield reduction and evapotranspiration (ET) reduction whcih are numerically equivalent was determined. The ET production function was implemented in matrix laboratory (MATLAB) to accurately determine the optimum soil moisture and irrigation water required for cowpea production. The results of the study indicated that 100% FIT excelled all other treatments at grain yield and biomass yield, where its yield was 1.06 t ha-1, the 80%, 60% and 40% FIT produced 0.95, 0.89 and 0.71 t ha-1 respectively. The analysis of the results showed that soil moisture availability was significantly (p<0.05) affected by the irrigation treatments adopted, which in turn significantly (p=0.05) affected the cowpea grain and biomass yield. The yield obtained at 40% FIT was significantly (p<0.05) different. The yield response factor of 1.24 was obtained, showing that cowpea is sensitive to water stress. The total amount of irrigation water and moisture content that resulted to the optimum yield were 151.12 mm and 0.1082 g g-1, respectively. The result implies that 32% of total irrigation water applied during the growing season would be saved. The approach adopted, therefore, proved to be useful in estimation of possible irrigation water required for optimum production of cowpea. [ABSTRACT FROM AUTHOR]

The biofortification of cowpea [Vigna unguiculata (L.) Walp.] lines will have great impact in semiarid regions, since the crop provides a rich source of food, especially of iron and zinc. The aim of the current study was to assess the adaptability and stability of iron and zinc concentrations and grain yield in cowpea lines to release new cultivars. Forty-four genotypes were distributed in two experiments, climbing and upright lines, with different population densities. They were assessed in four rainfed and three irrigated environments in two randomized block designs with three repetitions. Significant statistical differences were observed (p < 0.01) in the treatment, environment and treatment x environment interaction mean squares for all variables. The lines that showed the highest iron and zinc concentrations also showed grain yields below the overall mean in both experiments. The three applied methods showed similar results in the selection of superior materials. C4I and T16_2R in the climbing experiment and C2J in the upright experiment showed grain yield equal to or greater than the overall experiment means of 1034 and 1130 kg ha-1, respectively, with iron and zinc means concentrations 15% greater than the control cultivars, as well as wide adaptability and stability in the assessed environment. These lines could be released as new cultivars. [ABSTRACT FROM AUTHOR]

One hundred cowpea genotypes were screened against Bean common mosaic virus (BCMV) by artificial inoculation genotypes. The genotypes showed different disease reaction viz., immune, resistant, moderately resistant, Sap moderately susceptible, susceptible and highly susceptible. The SSR markers were characterized using a total of 25 randomly selected resistance and susceptible cowpea genotypes. Among, 10 SSR markers used to screen polymorphism, only 4 primers were found to be polymorphic and they were used for characterization and finding out genetic relationship of cowpea genotypes. The polymorphism information content (PIC) of these SSR markers ranged from 0.23 to 0.37 and single marker analysis (SMA) revealed, out of these 4 SSR markers M 135 marker explained 28.2 % of phenotypic variation (R2). The banding pattern of all cowpea genotypes were scored and dendrogram was constructed. A dendrogram of these genotypes based on SSR polymorphism divided into two major clusters at 35 % similarity. Cluster I was the biggest with 20 genotypes which was further separated as three sub-clusters. Whereas, 5 genotypes grouped in cluster II with two small sub-clusters. The clustering pattern of resistant and susceptible genotypes was not clear, however resistant genotypes such as V-5 and IC 8996 clustered in one group with 100 % similarity. The information provided by the identified markers would be very useful in breeding programs to select cowpea lines resistance to BCMV disease and M 135 was found to be good for rapid and accurate screening of cowpea genotypes against BCMV disease resistance. [ABSTRACT FROM AUTHOR]

Cowpea (Vigna unguiculata (L.) Walp.), a plant broadly cultivated for human consumption and animal feed, is among the most nutritious grain legumes. Most of the areas where cowpea is grown are drought-prone, and there is a need to address this issue, with water scarcity becoming a major concern in agriculture. Cowpea is known to form mutualistic associations with nitrogen-fixing (NF) bacteria and arbuscular mycorrhizal (AM) fungi. These beneficial soil microorganisms have the capacity to benefit plants by reducing the effects of environmental stresses, including drought. Our aim was to study the effect of inoculation with Bradyrhizobium elkanii and Rhizophagus irregularis on the growth and grain yield of cowpea under water-deficit conditions. Under moderate water deficit, grain yield was increased by 63%, 55% and 84% in plants inoculated with B. elkanii, R. irregularis and B. elkanii + R. irregularis, respectively. Under severe water deficit, inoculation with B. elkanii and B. elkanii + R. irregularis resulted in grain-yield enhancement of 45% and 42%, respectively. The use of cowpea inoculated with NF bacteria and AM fungi has great potential for sustainable agricultural production under drought conditions. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during kharif season of 2012 and 2013 at agricultural research farm, Palli Siksha Bhavana (Institute of Agriculture), Visva-Bharati, Sriniketan, West Bengal to study the effect of crop geometry and nutrient management in baby corn and cowpea (fodder) intercropping system on growth, productivity and competition functions of intercropping systems. The experiment was laid out in randomized block design having twelve treatments with each treatment replicated thrice. Higher number of corns ha-1, baby corn yield and green fodder yield of baby corn and cowpea were found in sole crop of baby corn and cowpea. This was significantly higher than various intercropping systems. Total green fodder yield from different intercropping systems was higher than sole cowpea but lower than sole baby corn. The treatment having 3:1 row ratio of baby corn and cowpea 100% NPK of base crop+75% PK of intercrop exhibited significantly higher total fodder yield over sole crop of cowpea and lower than sole crop of baby corn. Baby corn+cowpea (fodder) at 2:2 row ratio with 100% NPK of base crop+75% PK of intercrop exhibited the highest LER, monetary advantage (MA) and Area-time equivalent ratio (ATER) followed by baby corn+cowpea (2:1) with 100% NPK of base crop+75% PK or 50% PK of intercrop. However, the highest Relative Value Total (RVT) and Aggressivity (A) was recorded in 3:1 row ratio of baby corn and cowpea with 100% NPK of base crop+75% PK of intercrop and with 100% NPK of base crop+25% PK of intercrop respectively. The Relative Crowding Co-efficient (RCC) was observed in 2:1 row ratio of ratio of baby corn and cowpea with 100% NPK of base crop+75% PK of intercrop. [ABSTRACT FROM AUTHOR]

Cowpea cultivars, which are indicated for irrigated cropping, are recommended without proper assessment of their productive potential and water use efficiency in response to water regimes in the soil from different production environments. The aim of this study was to evaluate the production components, the yield performance and the efficiency of water use of cowpea cultivars in response to the application of irrigation depths under the soil and climate conditions of Bom Jesus, PI. The experiment was performed from June to August 2011 in a soil classified as sandy-textured Fluvic Neosol. The study was conducted in a randomized blocks design, with four replicates. The treatments were arranged in subdivided plots (irrigation depths in plots and cultivars in subplots). The cultivars BRS Aracê (semi-prostrate) and BRS Tumucumaque (semierect) were submitted to five irrigation depths (108.2, 214.7, 287.9, 426.1 and 527.7 mm). The number of pods per plant and the weight of one hundred grains are the main components related to grain yield. The cultivar BRS Tumucumaque presented a better yield performance (1697.2 kg ha-1) than the cultivar BRS Aracê (1233.8 kg ha-1), with the application of the irrigation depths of 527.7 and 522.4 mm, respectively. The highest water use efficiency (0.420 kg m-3) is obtained with the application of the irrigation depth of 108.2 mm in both cultivars. [ABSTRACT FROM AUTHOR]

Cowpea (Vigna unguiculata Walp.) is a warm-season legume with many traits that make it an attractive forage or cover crop for organic systems. Eight cowpea cultivars were evaluated under organic management at two locations for stand establishment, forage yield and quality, and weed biomass. The experiment was arranged in a strip-plot design with two P fertilization rates, amended (45 kg P ha-1) and unamended, to evaluate responsiveness to P fertilization in low native soil P status (Mehlich-1 P < 10 mg P kg-1). Cowpea was seeded at 209,000 seeds ha-1. Stand density at 4 wk indicated the highest plant populations from cultivar Iron & Clay (166,000 plants ha-1), intermediate populations from Speckled Purple Hull, IT82E-18, and IT85-867-5F (143,000 to 138,000 plants ha-1), and lowest populations from IAR7/8-5-4-1, Coronet, KV×396, and IT97K-556-4 (128,000 to 118,000 plants ha-1) primarily due to presence of seedling diseases caused by Fusarium spp. Speckled Purple Hull and Iron & Clay had the highest total yield (4922 and 4623 kg ha-1, respectively). Yield was lowest from IT82E- 18, Coronet and IAR7/8-5-4-1 (1958-2585 kg ha-1), likely due to low plant populations (IAR7/8-5-4-1, Coronet) and higher weed biomass than cowpea biomass (IAR7/8-5-4-1, Coronet, IT82E-18). There was no statistical difference in cowpea biomass between unamended (3422 kg ha-1) and P-amended plots (3150 kg ha-1), or differences in cowpea tissue P concentration. High forage quality values of top-performing cultivars suggest that they are well adapted to address low summer forage quality in applicable forage systems. [ABSTRACT FROM AUTHOR]

Intercropping is a way to intensify agricultural land use. Cowpea is an important crop in the traditional fanning systems in northern Nigeria because it serves to provide food and feed. Although lablab has potential to function in these ways, it remains an underutilized crop because among other factors, there is dearth of information on its incorporation into the system by way of intercropping it with the major cereal crops. A field trial was conducted at Samaru (11° 11'N, 07° 38'686 masl) in northern Guinea savannah of Nigeria, to evaluate the relative yield and yield components of dual-purpose lablab and cowpea cultivars when gown sole and when intercropped with maize of contrasting maturities. The experiment was laid out in a split-plot design with four replications. Tlte experiment consisted of early maize maturing cultivar (TZE COMP. 5 W) and a late maize maturing cultivar (TZL COMP. 1 SYN). Cropping system (intercropping and sole cropping) was assigned to the main plot and crop cultivar (lablab: ILRI4612, NApRl 2 and cowpea: IT89KD-288, IT99K-241-2) was assigned to subplots. Results showed that intercropping cowpea or lablab into early maturing maize cultivar was more productive than intercropping into late maturing maize cultivar for number of pods (74.4 vs. 63.9), harvest index (0.22 vs. 0.20), grain yield (575.7 vs. 441.0) and fodder yield (2075.4 vs. 1758.2) for the legumes. Lablab cultivars had superior performance than cowpea for number of pods (113.5-114.2 vs. 81.1-81.5) and fodder yield (2968.9-3042.3 vs. 1725.4-1795.9 kg ha-1) whereas cowpea cultivars had superior performance than lablab for harvest index (0.29 vs. 0.17) and grain yield (802.3-833.9 vs. 587.8-632.4 kg ha-1), meaning that both legumes have potential in providing food and feed with lablab producing more fodder and cowpea more grain. Land equivalent ratio showed that intercropping advantage was higher when lablab and cowpea were intercropped with early maturing maize cultivar (1.34,1.24) than with late maturing maize cultivar (1.10, 1.15). It is recommended that for higher lablab or cowpea/maize productivity in an intercrop, farmers should intercrop dual-purpose cultivars of these crops with maize of earlier maturities. [ABSTRACT FROM AUTHOR]

Plants usually tolerate drought by producing organic solutes, which can either act as compatible osmolytes for maintaining turgor, or radical scavengers for protecting cellular functions. However, these two properties of organic solutes are often indistinguishable during stress progression. This study looked at individualizing properties of osmotic adjustment vs. osmoprotection in plants, using cowpea as the model species. Two cultivars were grown in well-watered soil, drought conditions, or drought followed by rewatering through fruit formation. Osmoadaptation was investigated in leaves and roots using photosynthetic traits, water homoeostasis, inorganic ions, and primary and secondary metabolites. Multifactorial analyses indicated allocation of high quantities of amino acids, sugars, and proanthocyanidins into roots, presumably linked to their role in growth and initial stress perception. Physiological and metabolic changes developed in parallel and drought/recovery responses showed a progressive acclimation of the cowpea plant to stress. Of the 88 metabolites studied, proline, galactinol, and a quercetin derivative responded the most to drought as highlighted by multivariate analyses, and their correlations with yield indicated beneficial effects. These metabolites accumulated differently in roots, but similarly in leaves, suggesting amore conservative strategy to cope with drought in the aerial parts. Changes in these compounds roughly reflected energy investment in protective mechanisms, although the ability of plants to adjust osmotically through inorganic ions uptake could not be discounted. [ABSTRACT FROM AUTHOR]