Cowpea Production Research Articles

Morpho-physiological seed diversity and viability of Indonesian cowpea (Vigna unguiculata)

Abstract. Widajati E, Syukur M, Diaguna R, Permatasari OSI, Ritonga AW, Sahid ZD, Pratiwi GR, Hatta ANNL. 2023. Morpho-physiological seed diversity and viability of Indonesian cowpea (Vigna unguiculata). Biodiversitas 24: 5319-5327. Cowpea is a legume with a potential nutritional content almost equivalent to soybeans; it can be developed as a substitute agent for raw materials for food processing. One of the factors in obtaining high cowpea production is to use of quality seeds. Our study aimed to evaluate the performance and morpho-physiological correlations and viability of cowpea seed collections from IPB University Bogor and the Indonesian Research Institute of Legume. We used ten genotypes of cowpea, which had superior seed information. The results showed that the ten cowpea genotypes had superior morpho-physiological and seed viability. The seed germination percentage was categorized as medium-high (>60%). Eight cowpea genotypes were grouped into one major group based on morpho-physiological characteristics and viability. Furthermore, positive correlations were found between the observed variables of seed viability (seed germination, seed growth speed, and seed vigor index). Our research results are useful as a source of genetic diversity for plant breeders in developing new superior varieties in the future. In addition, agronomists can use this information to plant cowpeas based on planting location.

Productivity of Dry Grains of Cowpea [Vigna unguiculata (L.)] Creole Cultivar (Canupum), as a Function of Different Planting Densities

Aims: Cowpea [Vigna unguiculata (L.)] is a legume of great importance, being a source of food rich in protein, being essential for human nutrition and produced during the rainy season in the semi-arid region of Brazil. In this sense, the objective was to study the efficiency of different planting densities on cowpea productivity in the Brazilian semi-arid region.
 Place of Study: The experiment was conducted from September to December 2021 at the Rafael Fernandes experimental farm, in the district of Alagoinha (5º03'37 "S, 37º23'50" W), northwest of Mossoró, State of Rio Grande do Norte, Brazil,
 Study Design and Methodology: The experimental design used was randomized complete blocks with five treatments (1.0; 2.0; 3.0, 4.0 and 5.0 plants hole-1) with four replications. Each plot consisted of dimensions of 3.5 m x 4.8 m, with six rows of 4.8 m in length, with a total area of 18.2 m2, with the useful area being the four central rows, with dimensions of 2.8 x 4.8 m, with an area of 13.44 m2, for collecting dry grains.
 Agronomic Characteristics of Cowpea [Vigna unguiculata (L.)]: Number of pods, expressed in units ha-1 (NV), length of pods, expressed in cm (CPV), weight of one hundred grains, expressed in grams (P100G), dry grain productivity, expressed in kg ha-1 (PG), number of grains pod-1, expressed in units (GV), dry grain index, expressed in percentage (IGS) and pod production, expressed in grams (PV) of cowpea, Creole cultivar (canapum).
 Conclusions: The highest grain productivity was influenced by planting densities, with the density of 3.4 plants per pit being the one that resulted in the highest productivity (409.78 kg ha-1). For the characteristic weight of 100 dry grains, the density of one plant per hole was the one that promoted the highest average weight with a maximum value of 28.24 g.
 For farmers who cultivate in a family farming system, a planting density of three plants per hole is recommended.

Leaf Pruning Increased Seed Yield and Leaf Production of Cowpea (Vigna unguiculata L. Walp)

The leaves and pods of cowpea (Vigna unguiculata L. Walp) have potential uses as vegetables. This research aimed to assess the impact on cowpea growth and seed yield through different pruning times, methods, intensities, and their interactions. Conducted at the Cikabayan Experimental Field, IPB University, between April and August 2022, the study employed a randomized complete block design with three factors and three replications. The first factor, pruning time (5 and 7 weeks after planting, WAP), represented vegetative and generative phases. The second factor involved pruning methods (leaf and shoot), while the third focused on pruning intensity (0, 10, 30, and 50% of leaf numbers). This resulted in 16 treatment combinations, replicated three times, yielding 48 experimental plots. Measured variables included pruned leaf count, pruned leaf weight, total leaf count, plant fresh and dry weights, cowpea plant C/N ratio analysis, pod wet and dry weights, pod count, pod length, seeds per pod count, 100-seed weight, dry seed weight per plant, dry seed weight per plot, and cowpea seed productivity. Results highlighted significant effects of pruning time, method, and intensity on leaf count, shoot fresh and dry weights, and C/N ratio of cowpea plants after two weeks of pruning. However, the treatments did not significantly influence cowpea seed yield. Pruning cowpea leaves led to an average pruned leaf weight of 30 g per plant, offering a nutritious vegetable source without compromising cowpea seed yield. These leaves commanded a market price of approximately Rp. 6000 per kg, transforming them into a valuable economic asset when utilized as vegetables, thus contributing to the sale of nutritious food.

Sources of genetic resistance to Fusarium wilt (Fusarium oxysporum f. sp tracheiphilum) in cowpea (Vigna unguiculata (L.) Walp.) and comparison of inoculum concentration levels

Fusarium wilt caused by Fusarium oxysporum f. sp tracheiphilum (Fot) is a soil-borne fungal disease of significant constraint to cowpea production in West Africa. The disease infection can cause up to 100% yield loss in highly infested fields. The most effective control strategy is the use of resistant varieties. Sixty cowpea germplasm collections were screened for resistance to F. oxysporum. The result revealed that only two (TVu 134 and TVu 410) of the germplasm showed a high level of resistance when subjected to artificial epiphytotic and innovative seedling root dip screening methods using three inoculum concentration levels. These two cultivars can be used directly by farmers or as potential donors for developing resistant cultivars against F. oxysporum. The study also identified useful polymorphic SSR markers associated with resistant and susceptible parents, which will significantly enhance the breeding programs in developing varieties’ resistance to the disease.

Sorghum and cowpea productivity as influenced by tillage, cropping system with soil amendment in Centre-West Region of Burkina Faso

Improving crop productivity requires integrated management of soil fertility. This study aimed to assess the effects of tillage and the cropping system with soil amendment on the productivity of sorghum and cowpea. The experimental design was a completely randomized block with the treatments arranged in a split plot and three repetitions. Four tillage methods were allocated to the main plots and four cropping systems combined with four types of soil amendment were allocated to the sub plots. The results showed that ploughing and tied-ridging generated higher grain yields of sorghum than minimum tillage and manual zaï. The two cropping systems 1) 2 rows of sorghum alternated with 2 rows of semi-erect habit cowpea and 2) 1 or 2 row(s) of sorghum alternated with 1 or 2 row(s) of creeping habit cowpea in interaction with soil amendments generated higher grain yields for sorghum ranging from 895 to 1097 kg ha-1 and stover yields ranging from 1913 to 2370 kg ha-1 in the third year of study. Minimum tillage and ploughing proved to be more efficient in improving cowpea grain yields in the cropping system of 1 row of sorghum alternated with 1 row of creeping cowpea with soil amendment. These results show that tillage and crop association with soil amendments are likely to optimize agricultural productivity.

Wood Vinegar Promotes Soil Health and the Productivity of Cowpea

Wood vinegar (WV) is a biostimulant and a biopesticide that contains pyroligneous acid and is used as a crop growth enhancer and biocontrol agent, but insufficient information exists on WV’s effects on soil quality and cowpea production in Ghana. A field study (2 years) was conducted to determine the appropriate method of applying WV for soil health and cowpea production, and to determine the economic benefits of WV. Assessments were on nodulation, shoot biomass, yield, value–cost ratio, soil enzymes, soil respiration, microbial biomass nitrogen (MBN), permanganate-oxidizable carbon (POXC), mineralizable C, soil pH, available nitrogen and phosphorus. Results revealed soil drenching and foliar application are efficient methods of applying WV to achieve greater shoot dry matter, nodulation and grain yield of cowpea. Economically, soil drenching, followed by foliar application, generated better economic returns than the control. Adding WV to cowpea using soil drenching and foliar application improved soil health indicators. Soil enzymes and MBN were enhanced by WV applied foliarly and through soil drenching. Soil drenching with WV produced greater POXC and mineralizable C compared to the other treatments. Conclusively, WV applied foliarly and through soil drenching improved soil health, nodulation and yields of cowpea, and enhanced profitability.

Stochastic Frontier Analysis of Production, Socio-economic and Institutional Factors Affecting Technical Efficiency of Cowpea Production in Chuka Sub-county, Kenya

Cowpea is one of the most important vegetable that ranks third among pulses and top five leafy vegetables consumed in Sub Saharan Africa. In Kenya cowpea contributes to cheap supply of nutritious food, revenue and food security. Despite its importance, cowpea production levels are a fraction of the potential due to low technical efficiency of production which affects the revenue levels and food security of the smallholder farmers. This study aimed to determine the production, socio-economic and institutional factors affecting the level of technical efficiency among smallholder cowpea farmers in Chuka Sub County, Tharaka Nithi County, Kenya. Using semi structured questionnaire in a population of 12905 households and using multistage sampling technique from 389 households cross-sectional data on production factors, socioeconomic and institutional characteristics was collected. Data collected was analyzed using descriptive statistics and stochastic frontier production function. The results indicated that production factors, socioeconomic and institutional characteristics significantly affected cowpea production. The mean technical efficiency index was 0.34. The stochastic frontier analysis revealed that production factor coefficients of labour (0.825), topdressing fertilizer (0.635), manure (0.325), agrochemicals (0.221) and land size (0.628) were all positive and statistically significant at 5% level. The inefficiency model revealed that the coefficients of socio-economic factors age (0.038), education (-0.156) and farming experience (-0.053), and the institutional factors, information sources/extension contact (-0.669) and access to digital financial services (1.527) were negative but statistically significant, except for age and access to digital service that were positive and significant. These variables were the determinants of technical efficiency in cowpea production. The results suggest that there is potential for cowpea farmers to increase production and net profits in the long run by efficient utilization of the existing mix of production inputs and technologies. Formulation of policies revolving around the significant variables, input supply, technology transfer and subsidies; extension services, information exchanges and market linkages are recommended to palliate technical inefficiency in cowpea production among farmers.

Gender-disaggregated analysis of sustainable intensification practices adoption: A case of northern Ghana

Agricultural productivity has remained low in Africa, especially among smallholder farmers. Women often suffer resource constraints and access to certain technologies needed to increase productivity relative to men. This study analyzes the effect of gender on the adoption of selected sustainable intensification practices (SIPs) in northern Ghana using a sample of 463 farmers involved in maize and cowpea production. Probit regression analysis revealed that age, membership of a farmer-based organisation (FBO), and perception of ease of adoption (PEC) would likely influence the decision of females to adopt SIPs. FBO membership and ease of adopting technologies affect both male and female farmers to adopt SIPs positively. SIPs adoption decisions by males are influenced by many factors relative to those of females, thus highlighting the complexities involved in agricultural technology adoption. These findings have implications for policymakers and development practitioners working to bridge the gender gap in agricultural productivity, particularly in developing countries. The article makes an empirical contribution to the innovation and technology adoption literature, especially in terms of the factors that drive gender-transformative processes. Strengthening FBOs and utilizing the concept of technology parks to deepen farmers’ perceptions and understanding of SIPs could help bridge the gender gap in technology adoption and improve productivity.

Developing a Sustainable Spraying Regime for Cowpea Seed Production in South West Nigeria

Cowpea (Vigna unguiculata L. Walp) production in Nigeria is burdened by insect pest infestations throughout its developmental stages. Farmers rely on the use of conventional insecticides for insect pest control; however, these insecticides are often wrongly used, thereby resulting in undesirable effects on seed yield and the ecosystem. Cowpea was cultivated under different insecticide application regimes and its effect on seed production was evaluated at three substations of the Institute of Agricultural Research and Training, located at Ibadan in Oyo state (Rain forest transiting to derived savannah), Ilora in Oyo state (Derived savannah) and Ballah in Kwara state (Southern Guinea savannah). The trial was conducted during the cowpea cropping seasons of year 2018 and 2019. Ten treatments included 10 sprays of 2.5 EC lambda-cyhalothrin and cowpea varieties Ife Brown and IT2246. The experimental layout was split-split plot in a randomised complete block design. The results show a reduction in percentage aphids infestation as the spraying regimes increased on both cowpea varieties. The lowest values of 1.53 and 1.58% on Ife Brown and IT2246 respectively, were recorded on 200m/ha of four regime spray. Similar results were recorded on the number of thrips, the population of Clavigralla spp and number of pods/plant. Average seed yield under 3 spraying regime increased for both Ife Brown and IT2246 with increase in concentration of pesticide across locations except Ibadan where the yield reduced when the concentration was increased to 600 ml/ha. The spraying regimes of Lambda-cyhalotrin at foliage, flowering and podding have considerable potential for managing the pest of cowpea, but their impact of cowpea grain yield varies significantly.

Effect of Herbicidal Weed Management on Productivity and Profitability of Summer Cowpea

Background: The presence of weeds in cowpea reduced the yield to the tune of 60-82% depending on the weed flora and density. The critical period of weed competition in cowpea was 20-25 DAS. Therefore it is essential to control weeds effectively to harness the maximum yield potential of the crop. To manage weeds in cowpea it is also important to determine the efficacy of pre and post-emergence herbicides. Sequential application of herbicides in a short duration crop not only increases the cost of production but also create cumbersome in its application. Therefore ready mix herbicides are now becoming popular among farming community. These new ready mix herbicides need to be tested for its bio-efficacy to manage weeds and its effect on crop productivity and symbiotic characters of cowpea. Therefore, a field experiment was carried out to evaluate the impact of herbicides on the productivity and profitability of summer cowpea (Vigna unguiculata L.) at Agronomy Main Research Farm, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha (India) during summer season. Methods: The experiment was laid out at Agronomy Main Research Farm, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha (India) during the summer season of 2021 and2022 in a randomized block design (RBD) comprised of eight treatment with three replications. Standard procedures were followed for the observations and statistical analysis of the data. Result: The experimental results revealed that ready mix of pendimethalin+imazethapyr-750 g/ha significantly control the mixed flora of weeds which resulted significant increase in growth and yield. Ready mix application of pendimethalin + imazethapyr 750 g/ha registered the highest benefit to cost ratio.

Continuous assessment of cowpea [Vigna unguiculata L. Walp.] nutritional status using diagnosis and recommendation integrated system approach

Cowpea is one of the widely cultivated and consumed grain legumes in Africa, but its production is hampered by soil fertility degradation on farms. Here, we assessed the spatial nutritional diagnosis of cowpea and the variability of their productivity using the diagnosis and recommendation integrated system (DRIS) and geostatistics tool. We achieved a sampling of 200 geo-referred points in cowpea farms in four communes of Benin. In addition, we determined grain yield and the content of N, P, K, Ca, Mg, and Zn in the leaves. From DRIS, the order of nutrient deficiency was as follows: P > K > Ca > Zn > N > Mg; P > K > Ca > N > Zn > Mg; N > Mg > Zn > K > P > Ca; P > Ca > K > N > Mg > Zn, at Dassa-Zoume, Glazoue, Ketou, and Ouesse, respectively. Sampling points were close enough to detect the spatial variability of the DRIS Index, mean of nutrient balance index (NBIm), and cowpea productivity (spatial dependence index ˃ 50%). The combined analysis of the cowpea relative yield and NBIm maps showed that the NBIm map effectively indicated the spatial distribution of cowpea productivity. The spatial variability of the DRIS index has provided an accurate guide to where adjustments to fertilization rates are needed.

Optimizing the Application Timing of Liquid Organic Formulations and Their Effect on Sustainable Cowpea Production in Soils of Eastern Indian Plateau

Optimizing the Application Timing of Liquid Organic Formulations and Their Effect on Sustainable Cowpea Production in Soils of Eastern Indian Plateau

Recent advances in cowpea IPM in West Africa

Cowpea is an important and climate-resilient grain legume for human and livestock nutrition worldwide. Its grains represent a valuable source of protein for rural families in Sub-Saharan Africa while its haulms offer nutritious fodder for livestock, especially, in the Sahel regions. Cowpea production, unfortunately, faces substantial challenges of field and storage insect pests which can cause up to 100% losses. The use of synthetic pesticides, although providing farmers with a good level of pest control, has underscored the critical need for the development of integrated pest management (IPM) alternatives, due to their detrimental effects on humans, animals and the environment. This review examines recent advances in West Africa in cowpea IPM approaches, highlighting research on host plant resistance, biological control, biopesticides, good cultural practices, and on-farm participatory research and training undertaken to support sustainable cowpea production. Numerous IPM options have been developed, tested and validated for combating cowpea insect problems in West Africa by research institutions and disseminated through farmer field schools (FFS), field demonstrations, training sessions, and community-based education. Reviewing these environmentally safer and scalable IPM innovations will provide cowpea stakeholders with insights into workable, sustainable solutions for minimizing crop pest problems, reducing reliance on harmful pesticides and ultimately ensuring the long-term viability of cowpea production and its contribution to food security.

Exogenous Application of Organic and Inorganic Nutrients and Their Impact on Agronomical Traits, Yield and Quality of Vegetable Cowpea [Vigna unguiculata (L) Walp

The study was undertaken on heavy black soil at Regional Horticulture Research Station, Navsari Agricultural University, Navsari, Gujarat (India) in order to analyze the effect of foliar application of organic and inorganic nutrients on growth, yield and quality of vegetable cowpea. The field was thoroughly ploughed and harrowed followed by land levelling using wooden plank. Basal dose of manure and fertilizer of 20:40:00 kg ha-1 was incorporated in the soil during land preparation. The seeds were planted 45 cm between rows and 30 cm between plants laid out in a Randomized Complete Block Design with nine treatments replicated three times. Treatments were as follows: Control (T1), 2% Panchagavya (An organic solution made from cow dung, cow urine, cow butter, cow curd and cow milk) (T2), 3% Panchagavya (T3), 0.5% Novel plus organic liquid nutrients (T4), 1% Novel plus organic liquid nutrients (T5), 1.5 % Novel plus organic liquid nutrients (T6), 0.5% Micronutrient grade IV (T7), 1% Micronutrient grade IV (T8) and 1.5% Micronutrient grade IV (T9). The observations were made at the intervals of 60 and 90 DAS and data was collected on plant growth, yield and quality parameters. Results showed that the application of 1% Novel plus organic liquid nutrients (NOVEL) (T5) exhibited maximum plant height (35.73 and 56.93 cm, respectively), number of leaves per plant (39.27 and 52.73, respectively) at 60 and 90 days after sowing (DAS) and increased leaf area (162.14 cm2). Substantial effect of foliar application of 1% Novel plus organic liquid nutrients (NOVEL) (T5) was detected in yield parameters viz., number of clusters per plant (12.07), number of pods per plant (58.00), marketable pod yield (6.04 kg/plot). Furthuer to this, 1% Novel plus organic liquid nutrients indicated notable effect on protein content of pods (24.04%), iron (Fe) content (220.12 ppm) and zinc (Zn) content (62.76 ppm) of cowpea pods at final harvest. Novel Plus organic liquid nutrient can play a major role in growth, yield and quality in vegetable cowpea production.

Indicadores econômicos para o feijão-caupi cultivado sob diferentes lâminas de irrigação

ABSTRACT Cowpeas are of high socioeconomic importance in the North and Northeast regions of Brazil, whereby the search for alternatives that offer increased productivity with financial returns has become an important challenge. Thus, the objective of this study was to estimate and evaluate the economic indicators of cowpea production in 2015 and 2016 when applying drip irrigation to different depths. Irrigation treatments were based on crop evapotranspiration (ETc). The experiment was laid in a randomized complete blocks design with four treatments (0, 25, 50, and 100% ETc) and six replications. For economic analysis, the results were extrapolated to an area of one hectare. Productivity in 2015 was lower than that in 2016; however, in all treatments, it was always higher when plants were grown under adequate water supply. In both years, the total operating costs were higher under irrigation than under rainfed conditions. The 100% ETc treatment resulted in a greater number of cowpea bags (60 kg) produced and a higher gross revenue than the rainfed treatment by 17 bags ha-1, equivalent to 1,020 kg ha-1 (gross revenue US$ 711.48) and 16 bags ha-1, equivalent to 960 kg ha-1 (gross revenue US$ 867.12), in 2015 and 2016, respectively. Water deficit limited cowpea yield in both years but made cultivation economically unfeasible only in 2015.

Development and Process Optimization of a Ready-to-Eat Snack from Rice-Cowpea Composite by a Twin Extruder

A central composite rotatable design with four independent variables viz. blend ratio (broken rice flour and cowpea flour): 90:10–70:30, moisture content (10–18% wet basis), barrel temperature (110–150 °C), and screw speed (280–360 rpm) were varied in the development of ready-to-eat snacks using a twin extruder for a broken rice–cowpea product. The effects of the independent variables on specific mechanical energy, water absorption index, water solubility index, total color, hardness, bulk density, expansion ratio, and overall acceptability of the extruded snack were investigated using regression analysis. The results showed that the physical qualities of the ready-to-eat snacks were significantly affected by the extrusion parameters (i.e., blend ratio, barrel temperature, moisture content, and screw speed). From the findings, it was observed that screw speed and moisture contents affected hardness, while water absorption index was affected by all the extrusion parameters. However, the water solubility index and overall acceptance were majorly affected by the moisture content; extrudate produced with barrel ratio of 85:15, 12% moisture content, barrel temperature of 140 °C, and screw speed of 300 rpm was the most acceptable, at 6.73 on a 9 point hedonic scales. The blend ratio and barrel temperature influenced the expansion. Furthermore, the combination of cowpea and broken rice to produce nutritious ready-to-eat snacks has high acceptability and is a promising panacea for food security.

Weed-Hoeing Periods in Cowpea Cultivation under Direct and Conventional Systems.

Weed coexistence with an agricultural crop can negatively affect its growth, development, and yield. From this perspective, this study aimed to evaluate weed management strategies and their effect on the agronomic parameters of cowpea cultivation in direct (SPD) and conventional (SPC) planting systems. The experiment was set up in a completely randomized block design with a split-plot arrangement with four replications. The plots received a source of variation referring to the planting systems (direct and conventional planting), and the subplots corresponded to ten weed management strategies (manual hoeing 18 days after planting (DAP); at 36 DAP; at 54 DAP; at 18 and 36 DAP; at 18 and 54 DAP; at 18 and 72 DAP; at 36 and 54 DAP; at 36-72 DAP; at 18, 36, and 54 DAP; and a control with no hoeing). Density and dry mass evaluations of the cowpea plants were performed at harvest (72 DAP) by determining the number of pods per plant, pod length, number of grains per pod, 1000-grain mass, and yield. A total of 28 species distributed in 12 botanical families were identified in the two cultivation systems. The family Poaceae showed the highest frequency, with 25% of the species identified. At the end of the assay, treatment 20 had the highest positive influence and provided significant quantitative gains to the complex of traits related to cowpea production (SPD and hoeing at 18, 36, and 54 DAP). UPGMA cluster analysis and canonical discriminant analysis were performed and allowed a better classification of the evaluated treatments. It was observed that the first two canonical variables explained 90.8% of the total variance contained in the original variables. The use of SPD with weeding at 18, 36, and 54 days after planting provides greater weed control and significant quantitative gains for the complex of characteristics related to cowpea production. The results underscore the importance of choosing the correct cropping system and implementing effective weeding practices to optimize weed control and improve crop performance.

Growth and Productivity of Cowpea (Vigna unguiculata L.) in Response to Seed Priming and Different Levels of Phosphorus

Acidic soil generally has lower availability of phosphorus. Grain legumes respond positively to higher levels of phosphorus in acidic soil. Seed priming also enhances growth of the crops by activating various metabolic processes in plants. A field experiment was carried out to determine the influence of seed priming and phosphorus levels on growth and productivity of cowpea at Bhojad, Chitwan, Nepal. The experiment plot was laid out in two factorial randomized complete block design with three replications and the planting was done in spring season of 2022. The treatment consisted of two levels of seed priming (no priming and priming with 0.2 % Ca (NO3)2 for 24 hours) and four levels of P2O5 (20,30,40 and 60 kg ha-1). The variations in different parameters of cowpea due to seed priming were significant (P < 0.05). Primed seed produced the highest grain yield (1.25 t ha-1), which was followed by non-primed seeds (1.16 t ha-1). Similar significant (p<0.001) differences in yield and yield-attributing (no. of grains/pods, test weight, biological yield, grain yield and harvest index) traits were found at different levels of P2O5, with the highest grain yield (1.44 t ha-1) was obtained when applied with 40 kg P2O5 ha-1. Significant (p<0.001) variations in grain yield were found as a result of the interaction between priming and P2O5 levels. The combination of priming and 40 kg P2O5 ha-1 produced the highest grain yield (1.51 t ha-1). The results showed that the use of primed seed with 40 kg P2O5 ha-1 would be beneficial for the farmers in the Terai region of Nepal.

Design and Development of a Cowpea Decorticator

Introduction: Cowpea decorticating is a crucial post-harvest process that involves removing the seed coats from the kernels to produce ready-to-use cowpea products such as flour, grits, and protein concentrates and food products such as Akara and Moinmoin in south western Nigeria.
 Methodology: In this study, a locally developed cowpea decorticator was tested and evaluated using small oloka (a Nigerian local cowpea breed) cowpea grains. The machine was allowed to run empty for five minutes before the experiment commenced. Three samples of 1kg each were weighed and wetted with same quantity of water for 10, 20, and 30 minutes, respectively. The samples were then fed into the developed decorticator running at a speed of 420 rpm, and the operating speed and time taken were determined using a digital tachometer and stop watch, respectively. Samples of decorticated, undecorticated, and broken cowpea were collected and weighed to evaluate the efficiency of the machine based on the decorticating length and wetting time of cowpea grains.
 Results: The study revealed that as the decorticating length increased from 44.5 to 178 mm and wetting time increased from 10 to 30 minutes, the decorticating efficiency increased from 55 to 92.1%. The highest average decorticating efficiency of 92.1% was obtained at 178 mm decorticating length and 30 minutes wetting time.
 Conclusion: These findings showed that the decorticating efficiency of the machine depends on the wetting time and the decorticating length of the machine.

Biometric genetics in Cowpea beans (Vigna unguiculata (L.) Walp) II: estimates of genetic gains through selection indices

Low cowpea productivity (Vigna unguiculata (L.) Walp) in the semi-arid region of Paraíba is due, among other factors, to poor-quality cultivars. This research tested biometric models intending to increase productivity of superior cultivars with the following objectives: i. Estimate genetic gains in production components; ii. Identify the selection index model providing the greatest gains through simultaneously selecting a set of variables, and iii. Select cultivars with higher productivity. The experiment was carried out in the experimental field of the Agrifood Science and Technology Center of the Federal University of Campina Grande. Eight cultivars and 13 variables were evaluated. Data were subjected to ANOVA and means were grouped using the Scott and Knott test. Genetic gains were estimated by correlated response, classic selection index, rank sum and index based on desired gains. Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. Among the methodologies used, the classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. These results allow concluding that Costela de vaca, BRS Marataoã and Paulistinha cultivars should be selected for cultivation and commercial exploitation in the semiarid region of Paraíba. Highlights: Direct selection of the secondary pod yield component provides significant genetic gains in main grain yield. The classic selection index provided greater distribution of genetic gains for main grain yield and primary production components. Cultivars were selected for cultivation and commercial exploitation in the semi-arid region of Paraíba.