Cowpea Production Research Articles

Influence of Varieties and Integrated Nutrient Management Practices on Growth and Yield of Seed in Cowpea (Vigna unguiculata L.)

Background: Cowpea is one of the most important leguminous vegetable crops. It has a unique ability of biological nitrogen fixation and mobilization of insoluble soil nutrient and bringing qualitative changes in soil. The basic concept of integrated nutrient management system is to maintain of plant nutrients supply to achieve a good level of crop production by optimizing the benefits from all possible sources of plant nutrients in an integrated manner, appropriate to each farming system. Considering these aspects, a field experiment was conducted to boost up productivity of cowpea seed. Methods: A field experiment was carried out during Rabi season, 2015-16 at Research Field of the Department of Vegetable Science, College of Horticulture, Mandsaur (Madhya Pradesh). The experiment was arranged in factorial randomized block design with twenty treatment combinations comprising four cowpea varieties, viz. V1-Pusa Sukomal, V2-Kashi Unnati, V3-Kashi Kanchan and V4-Kashi Shyamal and five integrated nutrient management (INM) practices, viz. N1-Vermicompost 2.5t + Rhizobium (10g/kg seeds) + PSB (10 g/kg seeds) + N (0 kg) + P2O5 (90 kg) + K2O (70 kg)/ha; N2 -Vermicompost 2.5t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (15kg) + P2O5 (90kg) + K2O (70 kg)/ha; N3 -Vermicompost 2.5t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (20 kg) + P2O5 (90 kg) + K2O (70 kg)/ha; N4 -Vermicompost 2.5 t + Rhizobium (10 g/kg of seeds) +PSB (10 g/kg seeds) + N (25 kg) + P2O5 (90 kg) + K2O (70 kg)/ha and N5-Vermicompost 2.5 t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (30 kg) + P2O5 (90 kg) + K2O (70 kg)/ha. Result: In present experiment the cowpea variety V1-Pusa Sukomal recorded superior performance for growth attributes, yield and yield attributes and quality attributes. This variety had taken minimum days to first flowering, days to 50% flowering and days to harvesting. Among the nutrient levels, application of Vermicompost 2.5 t + Rhizobium (10 g/kg seeds) + PSB (10 g/kg seeds) + N (30 kg) + P2O5 (90 kg) + K2O (70 kg)/ha resulted in the highest growth parameters, yield and yield parameters of cowpea seed.

The nexuses between technology adoption and socioeconomic changes among farmers in Ghana

Agricultural technology adoption is critical to increasing productivity, profitability, and welfare of smallholder farmers. A high number of maize and cowpea production technologies have been developed, validated, and introduced to farmers. However, the adoption of these technologies continues to remain low and uneven and what really influences farmers’ decisions to adopt these technologies at the farm level is unclear. This study analysed the key drivers of the adoption of maize and cowpea technologies using recent comprehensive data collected through a household survey of 463 farmers. The study applied both the probit and logit models to estimate the factors influencing adoption in the study area. The study found a high rate of adoption among farmers with heterogeneous effects on the number of technologies adopted. Regional location of the farmer, age, FBO membership, distance to farm, access to credit, access to extension services and gender are the statistically significant factors that influence technology adoption in northern Ghana. Institutional strengthening such as FBOs and extension service provision as well as private sector participation that makes finance accessible to smallholder farmers has a great potential of catalysing the adoption of improved technologies for improving the welfare of farmers.

Limiting-Stress-Elimination Hypothesis: Using Non-hormonal Biostimulant to Reduce Stress and Increase Savanna Cowpea [Vigna unguiculata (L.) Walp.] Productivity.

An alternative decision axiom to guide in determining the optimal intervention strategy to maximize cowpea production is proposed. According to the decrement from the maximum concept of Mitscherlich, the decrement from the maximum for each stressor must be minimized to produce the absolute maximum production. In crop production, this means all deficient nutrients must be supplemented to ensure maximum yield and laid the foundation in fertilizer formulation. However, its implementation is not economically feasible in many situations, particularly where multiple environmental factors impact crop productivity as in the case of low resource conditions. We propose and test the hypothesis that yield allocation will increase when the most limiting stressor among prevailing stressors is eliminated at least until the next limiting stressor impacts productivity. We selected drought limiting savanna conditions and cowpea (Vigna unguiculata), adapted to nitrogen dependence. To determine the limiting condition, we measured the response of cowpea to D-sorbitol, nitrogen, and non-hormonal biostimulant (nhB) treatments. The nhB treatment increased total biomass by 45% compared to nitrogen, 13%, and D-sorbitol, 17%, suggesting osmotic stress is more limiting in the observed savanna conditions. The effect of the biostimulant is due to antioxidants and key amino acids that stimulate metabolism and stress resistance. Where nitrogen becomes the next constraining factor, biostimulants can contribute organic nitrogen. The study supports the use of biostimulants as candidate intervention under conditions where crop productivity is limited by multiple or alternating constraints during crop growth.

Genotypic differences in aluminum tolerance of cowpea accessions utilizing germination parameters

One of the major factors which limit the productivity of cowpea on acid soils is aluminum toxicity. Reliable methods for identifying genetic variation for its tolerance is indispensable. Genetic variability for aluminum tolerance in 10 accessions of cowpea were studied in the laboratory. Fifteen seeds of each accession were sown in sterilized petri dishes containing filter papers and 5 ml of AlCl3 at four levels (0, 50, 100 and 200 µm) and replicated three times in a completely randomised design (CRD). Petri dishes were incubated under room temperature in the dark for 48 hours. After 48 hours, they were exposed to photoperiod of 12 hr. / 12 hr. (day/night) at room temperature for another 48 hours. At day four after sowing, data were collected on percentage germination, number of roots per shoot, fresh weight of shoot, root length and hypocotyl length and fresh weight of shoot. Data were subjected to statistical analysis and accessions were arranged on their tolerance to aluminum stress by means of tolerance indices. Analysis of variance revealed significant effect of accessions on all parameters. Treatment was significant for all excluding percentage germination. Treatment by accession was significant for number of roots and root length. The observed genetic variation in cowpea for aluminum stress could be exploited by hybridisation to establish tolerant lines. Selection based on high heritability and GAM in percentage germination, hypocotyl length and number of roots in cowpea under aluminum stress can be exploited for selection.

Effect of salt stress on the parasitism of Meloidogyne enterolobii in cowpea

Cowpea, Vigna unguiculata (L.) Walp, is a very important Fabaceae in the diet of families in the northeast region of Brazil. This plant species is among the different cultures affected by the root-knot nematode. In this region, in addition to phytonematodes, another condition that affects cowpea productivity is salinity, one of the main abiotic limiting factors. The cultivar Pitiúba, however, has good adaptability to salt stress conditions. However, information on the behavior of root-knot nematodes in an environment with high levels of salinity for this crop is still scarce. Based on the above, the objective of this work was: 1) to evaluate the hatchability of J2 of Meloidogyne enterolobii in 100mM NaCl solution; 2) evaluate the motility and infectivity of J2 of M. enterolobii in saline solution at the levels of 0, 25, 50, 75, 100, 125, 150, 175, 200, 300, and 400mM; 3) to investigate the impairment of the development of M. enterolobii in cowpea Pitiúba under irrigation with NaCl solution at 100mM. It was found that J2 hatching, motility, and infectivity of juveniles of M. enterolobii were not affected by the levels of salinity tested in vitro. In Pitiúba, irrigation with 100 mM saline solution considerably affected the development of juveniles of the pathogen in the roots.

​Soil Suitability for Growing Pulses in Northern Dry Zone of Karnataka

Background: A soil suitability evaluation of Kanamadi South sub-watershed in the Northern Dry Zone of India was carried out during April 2019 to define the soil fitness for the production of pigeonpea, chickpea, greengram and cowpea the four major pulses that are widely grown in the area. Methods: A detailed soil survey of Kanamadi South sub-watershed was carried out using IRS P6 LISS-IV image and Vijayapura district toposheet. The soils of Kanamadi south sub watershed were grouped into 19 mapping units based on studied 50 profiles. The studied physical and chemical properties were evaluated using the FAO (1976) framework for land evaluation was followed in the evaluation of soil-site suitability for major crops grown in Kanamadi South sub-watershed. This classification recognized two orders of land suitability, order ‘S’ (suitable) and order ‘N’ (not suitable) which are further subdivided into land suitability classes. Result: The studied 19 mapping units were moderately (S2) to marginally suitable (S3) for pigeonpea and greengram having marginal to severe limitations of rainfall and soil physico-chemical properties and none to slight limitation of land form characteristics. The mapping units were moderately suitable (S2) to marginally suitable (S3) for chickpea and cowpea having moderate to severe limitation of temperature, rainfall, depth and pH and none to slight limitation of land form characteristics. The suitability of the study area for all the pulses were said to be moderately suitable (S2) for growing pulse crop for improving productivity and improving biological nitrogen fixation.

The witchweed Striga gesnerioides and the cultivated cowpea: A geographical and historical analysis of their West African distribution points to the prevalence of agro-ecological factors and the parasite's multilocal evolution potential.

The increasing severity of Striga gesnerioides attacks on cowpea across West Africa has been related to its prolificity, seed mobility and longevity, and adaptation to aridity, in a context of agricultural intensification. To understand this fast extension, we analyzed (1) the distributions of the crop and the witchweed with ecological niche modeling and multivariate climate analysis, and (2) the chronological information available from collections and the literature. The ecoclimatic envelope of S. gesnerioides attacks on cowpea is the same as on wild hosts. Consistently, the modeled distribution of cowpea infestations is closely similar to the simple superposition of the parasite model (involving all hosts) and the crop model. Striga gesnerioides infestations are restricted to the driest component of the cultivated cowpea ecoclimatic niche, corresponding to the Sahelian and Sudano-Sahelian belts and the Dahomey gap. Thus, the parasite distribution, determined by its own requirements, does not constrain cowpea cultivation under Guinean climates. The spatial and temporal distributions of S. gesnerioides field infestations are consistent with an earlier impact on cowpea production in eastern West Africa, related itself to a similar trend in cowpea cultivation intensification from Niger, Nigeria and Benin to Burkina Faso and Ghana. Mali and Senegal were affected later, and literature reports of Senegalese strains of S. gesnerioides from the wild developing virulence on cowpea offer a model for the diffusion of witchweed parasitism by multilocal evolution, through host-driven selection, instead of epidemic diffusion. A contrario, in Côte d’Ivoire, cowpea is much less widespread, so the parasite has remained confined to the wild compartment. Thus, both historical and ecogeographic analyses refute the vision of S. gesnerioides as an invader. Instead, they point to the increasing importance and intensification of the crop, and the consequent loss of biodiversity, as the main drivers of the extension and diversification of its crop-specific strains.

Flower bud thrips (Megalurothrips sjostedti Trybom) population diversity and sources of resistance among Benin cowpea germplasm

AbstractCowpea [Vigna unguiculata (L.) Walp.] is a main legume food cultivated for its leaves and grains in Benin. However, cowpea production is limited by insect pests with flower bud thrips being the most damaging and can cause up to 100% yield loss. Host plant resistance is the best strategy to control the pest. This study aimed to screen Benin cowpea germplasm for resistance to flower bud thrips. Forty‐eight accessions were evaluated under greenhouse conditions with reared flower bud thrips. Data were collected on thrips damage (score = 1–9), larvae and adults thrips counts in flowers, on yield and yield components. Data were subjected to analysis of variance, Pearson correlation and multiple linear regression analyses. Results showed that two thrips species (Megalurothrips sjostedti and Sericothrips occipitalis) attacked cowpea with M. sjostedti being the most dominant. The different collected populations of M. sjostedti caused similar damage to cowpea. Significant differences were observed among accessions for thrips damage, for yield and yield components. The accessions IT07K‐243‐1‐10, Nontchè‐Wagbèhamin, Kplobè‐Wewe, Kpegnikoun, Kpodjiguegue, Moussa, IT86D‐888, Sanzibanili and Sèwé were highly resistant to flower bud thrips by presenting low thrips damage and very few thrips counts in flower while Tiligré, IT83S‐742‐2 and IT84S‐2246‐4 were tolerant to thrips by presenting low thrips damage despite the presence of many thrips counts in flowers. These accessions could serve as resistance sources in breeding programs on cowpea in Benin.

Optimization of Cowpea Productivity and Seed Quality under Soil Natural Salinity Stress Using some Different Protective Treatments تحسين انتاجية وجودة بذور اللوبيا تحت إجهاد ملوحة التربة الطبيعية باستخدام بعض المعالجات المختلفة

This study was conducted with the aim is amelioration salinity stress and optimizes flowering, seed productivity and quality of cowpea(Kaha 1)under the stress of natural soil salinity using some different treatments during both successive seasons 2018-2019. The seeds of seed priming were grown under the same levels of natural saline stress, medium (5 dS/m) and high 7 dS/m) in two fields of El-Serw Agricultural Research Center, Damietta governorate. Sulfur (0.4 ton/fed.) and sulfuric acid (10 L/fed.)as soil amendments and chitosan (0.2 g/L), potassium silicate(1.1 g/L), and yeast extract (20 g/L)as different foliar applications in addition to untreated control. The layout of the current experiment was planned as split-split plot design in a completely randomized blocks design. The results conducted into a negative feedback of salinity stress on flowering, dry yield productivity and seed quality in comparing to improved ones by soil amendments or foliar applications. The major interaction in optimization flowering, dry yield and quality was less level of salinity stress (5 dS/m) interacted with mixed treatment between sulfur (0.4 ton/fed.), followed by sulfuric acid (10 L/fed.)amended with soil and sprayed with chitosan (0.2 g/L) or by yeast extract (20 g/L).Therefore, we recommend adding sulfur to the soil (0.4 ton/fed.) before planting as well as spraying plants with chitosan (0.2 g/l) or spraying with yeast extract (20 g/l) after 20 days of planting 3 times every 10 days to increase plant tolerance on soil salinity to obtain the best flowering, seed productivity and the highest quality under the same conditions.

Yield response of field‐grown cowpea varieties to Bradyrhizobium inoculation

AbstractCowpea [Vigna unguiculata (L.) Walp.] is a widely cultivated crop for food and animal feed, with a high potential for alleviation of climate change effects on crop production due to its biological nitrogen fixing ability. However, its yields are low in Ethiopia partly due to poor agronomic practices such as lack of improved varieties, low soil fertility, and limited input use including bio‐inoculants. Field experiments were conducted in the cropping seasons 2018 and 2019 at three climate change and food insecurity vulnerable sites in Ethiopia (Boricha, Dore, and Hawassa) to determine yield responses of cowpea varieties to Bradyrhizobium inoculation. Four cowpea varieties, Keti (IT99K‐1122), TVU, Black eye bean, and White wonderer trailing in combination with three inoculation levels (un‐inoculated or inoculated with Bradyrhizobium strains CP‐24 or CP‐37) were used in a factorial randomized complete block design with four replications. Results revealed significant varietal differences in crop yield and yield components over years and across sites. Averaged over the seasons, seed yield of TVU was higher by 52% compared to the low‐yielding Black eye bean variety. On average of the three sites, inoculation of cowpea with strain CP‐24 significantly increased seed yield (21%), pod number (16%), and 100‐seed weight (13%) relative to the control. Furthermore, the interaction between variety and inoculant resulted in a significant increase in seed yield and number of pods per plant of TVU × CP‐24 by 60 and 68%, respectively, as compared to the un‐inoculated treatment. Overall, inoculation of the cowpea varieties TVU and White wonderer trailing with Bradyrhizobium strains CP‐24 is recommended at all the three tested sites and similar agro‐ecological environments for improved productivity of cowpea.

Appraisal of cowpea cropping systems and farmers\u2019 perceptions of production constraints and preferences in the dry savannah areas of Nigeria

BackgroundLow plant density and wide intra-plant spacing in traditional cowpea cropping systems are among the factors responsible for low yield on farmers’ fields. Sole cropping and improved intercropping systems have been advocated in the last few years to increase yield in the dry savannah areas of Nigeria. This study investigated the level of adoption of high yielding cowpea cropping systems including factors that influenced their use and farmers’ perceived production constraints and preferences. A total of 420 farmers across 36 villages of northern Nigeria were interviewed, and data collected was analyzed using descriptive statistics to appraise farmers predominant cowpea cropping systems and factors that determine the use of sole versus intercropping were identified with the aid of binary logit regression. Furthermore, pairwise comparison ranking was deployed to understand farmers’ view of cowpea production constraints and preferred traits.ResultsThe results revealed that, many of the farmers (42%) still grow cowpeas in the traditional intercropping and a good number (25%) cultivate the crop as a sole crop, while 23% had fields of cowpeas in both sole and intercropping systems. Farmers reported the incidence of high insect pests, limited access to land, desire to have multiple benefits, and assurance in the event of crop failure as reasons for preference for intercropping over sole planting. The pairwise comparison ranking of constraints and preferences revealed insect pests, Striga, drought and poor access to fertilizers as major constraints to increased productivity. Many farmers indicated high yield as the most preferred trait.ConclusionsFindings indicate a need for increased education and training of cowpea farmers on the importance of growing cowpeas in sole cropping and or improved intercropping systems. Genetic improvement efforts should focus on developing cowpea varieties that address farmers production constraints and reflect the diversity of consumers’ preferences for the crop. Hence, breeding for resistance to insect pests and high yield is recommended as an important priority of cowpea breeding programmes in the region.

Production and biochemical responses of cowpea under thermal and water stress

Water deficit and high temperature limit agricultural productivity, affecting plant growth, development, and metabolism. Thus, the objective of this study was to evaluate the impact of the interaction between water deficit and temperature increase on cowpea production. The experiment was carried out with the cultivar BRS Rouxinol, in growth chambers, in a 4 × 2 factorial arrangement, being four soil water availability (25; 50; 75 and 100% of field capacity) and two daily temperature regimes (T°1: 20-26-33 °C and T°2: 24.8-30.8-37.8 °C). The increase in water availability favored an increase in shoot and root dry mass. The vegetative stage was prolonged in plants maintained at a temperature regime of 24.8-30.8-37.8 °C. The cowpea yield increased with higher water availability. The water availability of 90% was the one that provided the highest water use efficiency. The 4.8°C increase in air temperature promotes an increase in oxidative stress with lack of synchrony in the antioxidative defense system. The cultivar Rouxinol is sensitive to the increase in air temperature and water deficit. However, even with 100% water availability, there was no seed production with an increase in air temperature.

Effect of cashew (Anacardium occidentale) nut shell stored and fresh extracts on cowpea bruchid, Callosobruchus maculatus (Fabricius.) (Coleoptera: Chrysomelidae)

Effect of cashew (Anacardium occidentale) nut shell stored and fresh extracts on cowpea bruchid, Callosobruchus maculatus (Fabricius.) (Coleoptera: Chrysomelidae)

Cowpea subjected to organic fertilization and management of the natural vegetation of the savannah of Roraima

Cowpea (Vigna unguiculata (L.) Walp.) is one of the main sources of nutrients for a large part of the population. To increase your income, there is a need for proper management. This study aimed to evaluate yield components of the cowpea cultivar Aracê subjected to two levels of organic fertilization and three management of the natural vegetation of the savannah of Roraima. The experiment was set up in the experimental area of CCA/UFRR, in Boa Vista, Roraima. The experimental design was a randomized block design in a 3×2 factorial scheme, with four replications. The first factor consisted of the management of the natural vegetation: glyphosate application and cutting or not of the natural vegetation. The second factor consisted of the application or not of cattle manure. Yield components were plant height, number of trifoliate leaves, percentage of normal pods, pod length, number of grains per pod, 100-grain weight, sample grain index, total grain index, and final stand. Organic fertilization with 2 L m-2 of manure increased cowpea production. The management with vegetation cutting in areas with organic fertilization increased the final stand of cowpea plants. The desiccation of natural vegetation with glyphosate was the management that had the highest cowpea production.

Essential oils from Betula lenta, Cinnamomum cassia, Citrus aurantium var. Amara and Acorus calamus as biopesticides against cowpea weevil

Cowpea (Vigna unguiculata) is an important crop as a source of basic protein for populations in tropical countries, generating profit after the processing and storage of grains. However, the attack of pests such as cowpea weevil Callosobruchus maculatus (Coleoptera: Chrysomelidae: Bruchinae) can limit the production of cowpea, with the insect causing qualitative and quantitative losses to the grains. Its control is commonly performed with fumigant phosphine, which due to its almost exclusive use, has selected resistant populations of insects, causing control failure. This way, the present research aimed to investigate the effects of essential oils of Betula lenta, Cinnamomum cassia, Citrus aurantium var. Amara and Acorus calamus in the treatment of cowpea grains [Vigna unguiculata (L.) Walp.] under storage conditions, for the management of Callosobruchus maculatus. The effects of essential oils were investigated through contact, fumigation, and repellency tests. The LC50 found in the test of contact was 0.61; 0.63; 0.64 and 22.98 μL/20 g of beans for the oils of A. calamus, B. lenta, C. cassia, and C. auratium var. Amara, respectively. Based on the data, the number of eggs and insects that emerged decreased as the concentration of essential oils increased. The LC50 values in the fumigation test were estimated at 5.16; 8.24; 25.84 and 35.31 μL/L of air for A oils. calamus, B. lenta, C. auratium var. Amara and C. cassia, respectively. In the repellency test, all oils acted like antagonists to C. maculatus biology, but the latter presented deterrence against the oviposition and the emergence of adults in most concentrations. These findings indicate that essential oils can be used to manage C. maculatus.

MECHANICAL PROPERTIES OF COWPEA BEANS AT DIFFERENT MOISTURE CONTENTS

Cowpea production has gained considerable ground in Brazil. Cowpea grain undergo different types of pressure and may crack and break during processing and storage, thus, there is a need to classify the mechanical properties of the beans. Therefore, this study aimed to evaluate the influence of the moisture content of cowpea beans on the maximum compressive force for fixed deformation and determine the proportional modulus of deformity under compression. The cowpea cultivars Novaera and Tumucumaque were evaluated at different moisture contents (0.12; 0.15; 0.18; 0.20; and 0.23 decimal d.b.). The experiment was arranged in completely randomized design for each moisture content and 10 deformation rates were applied (0.02; 0.04; 0.06; 0.08; 0.10; 0.12; 0.14; 0.16; 0.18; and 0.20 mm). The compression force was assessed using a universal testing machine and the proportional deformation modulus was determined. Following, hardness and elasticity of cowpea beans ??as a function of the moisture content were established. The compressive force required to deform cowpea beans decreases with increasing moisture content: between 2 and 105 N (Tumucumaque) and between 2 to 97 N (Novaera). The proportional deformation modulus of cowpea increased as the moisture content and deformation reduced, ranging from 4.9 x 107 to 31.9 x 107 Pa (Tumucumaque) and from 5.9 x 107 to 42 x 107 Pa (Novaera).

Assessment of morpho-variability between bruchid tolerant AND SUSCEPTIBLE cowpea (Vigna unguiculata L. Walp.) accessions

Cowpea bruchid is a major constraint to cowpea production. Easy identification of resistant/tolerant accessions to bruchid infestation has been a major challenge in bruchid resistant breeding programmes. Hence, the study was aimed to evaluate variations in some morphological characters between some bruchid resistant/tolerant and susceptible cowpea accessions, correlating them with their bruchid tolerance status in the hope of identifying a pointer character(s) that can facilitate easy identification of bruchid tolerant among cowpea germplasm. Sixty accessions were collected and evaluated for bruchid tolerance. Accessions were then grouped into bruchid susceptible and bruchid tolerant. These accessions were planted in Randomized Complete Block Design with ten replicates. Morphological differences between groups were evaluated accordingly. Of the sixty accessions evaluated, fifty-two were susceptible while eight were bruchid tolerant. No qualitative differences were observed between bruchid susceptible and tolerant groups, however significant differences were observed in quantitative characters which include terminal leaflet length, terminal leaflet/width ratio, leaf petiole length, terminal leaflet petiole length (TLPL), leaf petiole length, pod length (PDL), pod width, total number of pods per plant, seed length (SDL), seed width (SDW), seed thickness (SDTK) and 100 seed weight (100SDW). Bruchid tolerance was significantly positively correlated with seed characters which include, SDL (r = 0.798, p < 0.01); SDW (r = 0.798, p < 0.01); SDTK (r = 0.758, p < 0.01);100SDW (0.830, p < 0.01) and significantly negatively correlated with TLPL and PDL (p < 0.05). These characters can provide easy identification of bruchid tolerant among cowpea germplasm, hence requires further investigations.
 Keywords: Cowpea, Vigna unguiculata, Bruchid, Callosobruchus maculatus, Morphology

Differential responses of two cowpea (Virgina unguiculata L.Walp.) genotypes to pre-emergence herbicides in the savannah woodland and rainforest agroclimatic regions of Sierra Leone

Field trials were conducted in savannah woodland (Njala) and rainforest (Serabu) agroclimatic regions of Sierra Leone during 2016 second cropping season to assess different preemergence herbicides techniques that is efficient, cost effective and environmentally safe in cowpea production. The experiment consisted of 20 treatments which included 2 cowpea genotypes (slipea 4 and slipea 5) and 10 different weed control techniques viz: butachlor 50% emulsifiable concentrate (EC), double force®, power force® applied as preemergence herbicides at 2, 4 and 6 L ha-1, respectively and weedy check. The treatments were laid out in a strip-plot design arranged in a factorial system with three replications. The results of this study revealed that the application of power force® at 6 L ha-1 recorded the highest phytotoxic effect, lowest weed dry weight, number of pods per plant and grain yield, highest total variable cost, lowest gross and net returns. Furthermore, butachlor 50% EC at 2 L ha-1 closely followed by double force® at 6 L ha-1 resulted in maximum grain yield, gross and net returns compared to the rest of the other weed control techniques. Thus, it is concluded that butachlor 50% EC at 2 L ha-1 was more economical, profitable and beneficial than other control treatments in the production of cowpea genotypes in the savannah woodland and rainforest agroclimatic regions of Sierra Leone. Conclusively, the relationship between phytotoxicity and grain yield indicates that the higher the grain yield the lower the phytotoxic effects of the chemicals.

Impact of Different Nitrogen forms on Soil Fertility and Cowpea Productivity under Conditions Saline Soil

The field experiment was carried out at the south-west portion of Shall El-Tina region, north Siena Governorate Egypt. The study investigated evaluations of different nitrogen fertilizers sources (ammonium nitrate, ammonium sulphate and urea fertilizers) and rates (100%, 75% and 50% recommended dose of all different nitrogen forms) alone or combined with bio-fertilizer (Rhizobium radiobacter sp.) strain on improve nutrients available and contents in cowpea productivity in newly reclaimed saline soil conditions during two summer seasons 2019 and 2020. The studies treatments were disturbed among the experimental plots in split design. The obtained results showed that using ammonium sulphate fertilizer was more effect on EC, pH, and available N, P, K, Fe, Mn and Zn values by increasing application rates compared with other treatments. Moreover, data recorded the applied ammonium sulphate75% with bio-fertilizer was increase of plant height, weight of 100 seeds, weight of pods (g plant-1), seeds yield (ton fed-1) have been affected by inoculation with bio-fertilizer combined with different nitrogen forms and different application rates than other treatments. The highest values of N, P, K, Fe, Mn and Zn concentrations and uptake in seeds were obtained with ammonium sulphate application combined with bio-fertilizer compared with other treatments. The increase of chlorophyll, protein contents in cowpea plants with decreasing soil salinity, while the increase of proline content was increasing soil salinity. The application of ammonium sulphate at application rate 75% N combined with bio-fertilizer improves soil properties and cowpea productivity under saline soil conditions.

An investigation of cowpea production constraints and preferences among small holder farmers in Nigeria

The gradual decline in cowpea production in Nigeria, the largest cowpea producing country, has been of concern. Hence, assessment of challenges and constraints to cowpea production among small holder farmers in some cowpea producing states was carried out using 150 randomly selected respondents. These farmers were selected from communities in four cowpea producing states. Structured questionnaire was used to source for information from the sampled respondents and data collected were analysed accordingly. The sampled population comprise of 90% males and 10% females mostly between 20 and 50 years. The farmers had secondary education (54.4%) and were mostly married (97%). Land used by these farmers were mostly inherited (58.98%) and cowpea was mixed cropped with other crops during its growing season. However, drought, pest and diseases both on the field and in storage were the top ranked production constraints reported by the respondent. There was also high preference for drought tolerant, pest and disease resistant, high market acceptability, large seeds and early maturing cowpea varieties. We therefore recommend the introduction and promotion of resistant varieties to cowpea farmers that would foster increased cowpea production.