Response Of Cowpea Research Articles

Response of cowpea (Vigna unguiculata L.) to integrated nutrient management practices in Sethu Bhaskara Agricultural College and Research Foundation, Karaikudi, Tamil Nadu

Response of cowpea (Vigna unguiculata L.) to integrated nutrient management practices in Sethu Bhaskara Agricultural College and Research Foundation, Karaikudi, Tamil Nadu

Contrast Relative Humidity Response of Diverse Cowpea (Vigna unguiculata (L.) Walp.) Genotypes: Deep Study Using RNAseq Approach.

Cowpea (Vigna unguiculata (L.) Walp.) is appreciated for its suitability for cultivation and obtaining good yields in relatively extreme farming conditions. It is resistant to high temperatures and drought. Moreover, food products prepared from Vigna are rich in many nutrients such as proteins, amino acids, carbohydrates, minerals, fiber, vitamins, and other bioactive compounds. However, in East and Southeast Asia, where the products of this crop are in demand, the climate is characterized by excessive humidity. Under these conditions, the vast majority of cowpea varieties tend to have indeterminate growth (elongated shoot length) and are unsuitable for mechanized harvesting. The molecular mechanisms for tolerance to high relative humidity remain the least studied in comparison with those for other abiotic stress factors (drought, heat, cold, flooding, etc.). The purpose of the work was to reveal and investigate differentially expressed genes in cowpea accessions having contrasting growth habits (determinate and indeterminate) under humid and drought conditions. We performed RNA-seq analysis using selected cowpea accessions from the VIR collection. Among the genotypes used, some have significant changes in their plant architecture in response to high relative humidity, while others were tolerant to these conditions. In total, we detected 1697 upregulated and 1933 downregulated genes. The results showed that phytohormone-related genes are involved in cowpea response to high relative humidity. DEGs associated with jasmonic acid signaling are proposed to be key contributors in the maintenance of compact architecture under humid conditions.

Synergistic application of Bradyrhizobium yuanmingense and Trichoderma species improves tolerance of cowpea to aluminum stress by enhancing the antioxidant defense system

The positive effects of Trichoderma on the antioxidant responses of nodulated cowpea plants under aluminum (Al) stress are not well documented. This study aims to evaluate the effects of different microbial consortia of Bradyrhizobium yuanmingense (bradyrhizobia) and Trichoderma species (T. asperelloides T02, T. asperellum T77, or T. harzianum T78) on the growth and antioxidant responses of cowpea under Al stress. Coinoculation with Bradyrhizobia and Trichoderma resulted in greater growth (plant height and root length) and biomass (dry weight of shoots and roots) compared to single inoculations. The dual application of bradyrhizobia and T. asperellum T77 to Al-treated plants increased chlorophyll-a (36 %), chlorophyll-b (210 %), and carotenoid (92 %) contents. Under Al stress, plants inoculated with bradyrhizobia exhibited a 53 % increase in anthocyanin content compared to the unstressed control. The highest levels of reduced ascorbate and ascorbate redox state were observed in plants coinoculated with bradyrhizobia and Trichoderma, whereas oxidized ascorbate accumulated more in plants with single inoculations (bradyrhizobia or Trichoderma). Lipid peroxidation and hydrogen peroxide levels were 50 % lower in plants coinoculated with bradyrhizobia and Trichoderma. Additionally, these plants showed increased activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidases under Al stress, particularly in those coinoculated with bradyrhizobia and T. asperelloides T02 and T. harzianum T78. Our results confirm that the presence of bradyrhizobia and Trichoderma in the cowpea rhizosphere mitigates oxidative damage caused by reactive oxygen species under Al stress and positively influences cowpea growth and development under stressful conditions.

Enhancing cowpea wilt resistance: insights from gene coexpression network analysis with exogenous melatonin treatment

BackgroundCowpea wilt is a harmful disease caused by Fusarium oxysporum, leading to substantial losses in cowpea production. Melatonin reportedly regulates plant immunity to pathogens; however the specific regulatory mechanism underlying the protective effect of melatonin pretreated of cowpea against Fusarium oxysporum remains known. Accordingly, the study sought to evaluate changes in the physiological and biochemical indices of cowpea following melatonin treated to facilitate Fusarium oxysporum resistance and elucidate the associated molecular mechanism using a weighted gene coexpression network.ResultsTreatment with 100 µM melatonin was effective in increasing cowpea resistance to Fusarium oxysporum. Glutathione peroxidase (GSH-PX), catalase (CAT), and salicylic acid (SA) levels were significantly upregulated, and hydrogen peroxide (H2O2) levels were significantly downregulated in melatonin treated samples in roots. Weighted gene coexpression network analysis of melatonin- and Fusarium oxysporum-treated samples identified six expression modules comprising 2266 genes; the number of genes per module ranged from 9 to 895. In particular, 17 redox genes and 32 transcription factors within the blue module formed a complex interconnected expression network. KEGG analysis revealed that the associated pathways were enriched in secondary metabolism, peroxisomes, phenylalanine metabolism, flavonoids, and flavonol biosynthesis. More specifically, genes involved in lignin synthesis, catalase, superoxide dismutase, and peroxidase were upregulated. Additionally, exogenous melatonin induced activation of transcription factors, such as WRKY and MYB.ConclusionsThe study elucidated changes in the expression of genes associated with the response of cowpea to Fusarium oxysporum under melatonin treated. Specifically, multiple defence mechanisms were initiated to improve cowpea resistance to Fusarium oxysporum.

Pollen Viability, and the Photosynthetic and Enzymatic Responses of Cowpea (Vigna unguiculata (L.) Walp., Fabaceae) in the Face of Rising Air Temperature: A Problem for Food Safety

Rising temperature affects agricultural production, causing food insecurity. Thus, the objective of this study was to evaluate how increased temperature influences pollen viability, photosynthetic and enzymatic responses, and their consequences on the final yield of cowpea cultivars. The cultivars BRS Acauã, BRS Guariba, BRS Gurguéia, and BRS Pajeú were used, kept in growth chambers under two temperature regimes: 24.8–30.8–37.8 °C and 20–26–33 °C. The cultivars BRS Acauã, BRS Guariba, and BRS Pajeú showed prolonged flowering and greater flower abortion, at 23.58%, 34.71%, and 25.55%, respectively, under an increase of 4.8 °C in temperature. This increase also reduced the viability of BRS Acauã and BRS Pajeú pollen by 34 and 7%, respectively. Heating increased stomatal opening and transpiration but reduced chlorophyll content. The enzymatic response varied according to cultivars and temperature. Changes in photosynthetic and enzymatic activities contribute to reducing pollen viability and productivity. BRS Acauã was the most affected, with an 82% reduction in the number of seeds and a 70% reduction in production. BRS Gurguéia maintained its production, even with an increase of 4.8 °C, and can be selected as a cultivar with the potential to tolerate high temperatures as it maintained pollen viability, with less flower abortion, with the synchrony of physiological and biochemical responses and, consequently, greater production.

Response of cowpea (vigna unguiculata l.) to organic and chemical fertilizer applications on grain yield and yield components

Grain of cowpea are used for human diet and its grain contains high protein, minerals and vitamins. Cowpea was also used as hay, silage, green forage, grain fodder for feed livestocks. The experiment was conducted under irrigated conditions in the experimental area of Field Crop Deparment, Faculty of Agriculture, Cukurova University, Balcalı, Adana, Turkiye. The growing period covered throughout 2021 and 2022. The field experiment was organized in split plots based on randomized complete blocks design with three replication. Two registered cultivars (Karagöz ve Akkız) were used as a research material. In this experiment the main plots were cultivars and sub-plots were application of fertilizer. Treatments were: control (no fertilizer), solid leonardite, liquid leonardite, basal chemical dose + solid leonardite, basal chemical dose +liquid leonardite, basal chemical fertilizer + additional N fertilizer. Basal chemical dose was application of 40 kg N ha-1 and 100 kg N ha-1 P2O5 (Di ammonium phosphate or DAP) before sowing as recommended chemical fertilizer. Addition chemical dose was application of 80 kg N ha-1 (Ammonium sulfate) over the basal dose at the seedling stage. Rhizobia inoculant was not applied during the field experiment. Akkız seed yield was significantly higher in application of liquid leonardite fertilizer and the combination of basal chemical fertilizer + liquid leonardite fertilizer with 1656 and 1533 kg ha-1 respectively, compared to other treatments. The grain yield in the control plot was the lowest in both cultivars. As a result, applying liquid leonardite fertilizer into the soil before sowing can be useful for grain production in cowpea.

Response of Cow pea (Vigna unguiculata L.) to seeds rate and Foliar spray of Ca Nanoparticles

Field experiment conducted at summer in two season 2020-2021 and 2021-2022 on clay sandy soil in Al-Diwanyia. The experiment was design as Complete randomized block designing with three replications arranged for split-pilot design, and Lest Significant Deference's( LSD) 0.05 the main treatment contend two groups seeds rate 25 and 50 Kg ha-1 within there four levels of Nano Ca( 0 , 30 , 60 , 90) PPM I took sample of soil before planting to analysis it and to learn physical and chemical properties table 1. Cowpea( Vigna unguiculata L.) were sowing at two rates 25 and 50kg.ha-1(3 cm depth) at 1/4 , after 7 months I took a samples to measure . The results showed all factors and interactions were significant effect and increased all growth traits (plant height, number of leaves per plant and stem diameter , plant content of protein , carbohydrate total Chlorophyll and fats and active substances ,) lead to increased grain yield max values (2.72 Ton.ha-1) at interaction of 25 seeds rate and 90 ppm Ca Nanoparticles level, while min value(1.9 Ton.ha-1) at interaction 50 seed rate and 0 ppm Ca Nanoparticles level.

Response of Cow pea (Vigna unguiculata L.) to seeds rate and Foliar spray of Ca Nanoparticles

Field experiment conducted at summer in two season 2020-2021 and 2021-2022 on clay sandy soil in Al-Diwanyia. The experiment was design as Complete randomized block designing with three replications arranged for split-pilot design, and Lest Significant Deference's( LSD) 0.05 the main treatment contend two groups seeds rate 25 and 50 Kg ha-1 within there four levels of Nano Ca( 0 , 30 , 60 , 90) PPM I took sample of soil before planting to analysis it and to learn physical and chemical properties table 1. Cowpea( Vigna unguiculata L.) were sowing at two rates 25 and 50kg.ha-1(3 cm depth) at 1/4 , after 7 months I took a samples to measure . The results showed all factors and interactions were significant effect and increased all growth traits (plant height, number of leaves per plant and stem diameter , plant content of protein , carbohydrate total Chlorophyll and fats and active substances ,) lead to increased grain yield max values (2.72 Ton.ha-1) at interaction of 25 seeds rate and 90 ppm Ca Nanoparticles level, while min value(1.9 Ton.ha-1) at interaction 50 seed rate and 0 ppm Ca Nanoparticles level.

Response of cowpea plants submitted to acid conditions: Aluminum and hydrogen stress

ABSTRACT Aluminum (Al) is an important abiotic stress factor constricting the production of cowpea (Vigna unguiculata (L.) Walp.) in acid soil conditions. This study investigated the effect of Al and pH levels on the photosynthesis, proline accumulation, and nutritional status of two cowpea cultivars. Two pot experiments under greenhouse conditions were performed concurrently. Each experiment was carried out using a completely randomized design, in a factorial scheme 2 × 3 +1, in which each cultivar was exposed to two levels of Al (0.0 and 1.0 mmol L -1 ) and three levels of pH (3.3; 4.0, and 4.7), plus a control. There was an interaction effect of the factors Al and pH reducing significantly the internal CO 2 concentration (Ci) for BRS Caldeirão, and transpiration (E) and stomatal conductance (gs) for BRS Tracuateua, notably under growth conditions with Al (1 mmol L -1 ) and pH value of 4.7. For BRS Caldeirão, proline content was significantly reduced by the isolated effect of the factors Al and pH on shoot tissue. For BRS Tracuateua, proline content was significant only in roots, indicating a metabolic response to water stress damage. Under growth conditions with Al and pH value of 3.3, there was an improvement in nutrient uptake and accumulation according to nutritional status of both cultivars. In summary, cowpea response pointed that physiological, biochemical, and nutritional aspects of both cultivars improved at the lowest pH of 3.3 under Al-stress, and also that cv. BRS Tracuteua was less tolerant than BRS Caldeirão.

Waterlogging stress reduces cowpea (Vigna unguiculata L.) genotypes growth, seed yield, and quality at different growth stages: Implications for developing tolerant cultivars under field conditions

Waterlogging is a significant abiotic stress that reduces the oxygen supply to roots in the rhizosphere, impairing plant growth and development. Cowpea is highly sensitive to waterlogging, and their grain yield is affected by genotype and growth stage. Understanding the growth and physiological responses of cowpea to waterlogging stress is crucial for developing strategies to improve crop yield in waterlogged environments. In this two-year field trial, we quantified the impact of ten days of waterlogging on morpho-physiological attributes, seed yield components, and seed quality of two cowpea genotypes (UCR 369 and EpicSelect.4) at different growth stages. Waterlogging during the reproductive (R2) growth stage had the most substantial impact on cowpea, with an average reduction of leaf area by 65%, chlorophyll content by 39%, stomatal conductance (gs) by 93%, and photochemical efficiency by 32% compared to non-waterlogged plants. These effects were less pronounced during the vegetative (V4) and physiological maturity (R7) growth stages. Lower photosynthetic capacity resulted in reduction of biomass accumulation, pod dry weight, number of pods per plant, and seed weight under waterlogging. EpicSelect.4 was more sensitive to waterlogging at the R2 stage, showing a greater reduction in seed yield (58%) compared to UCR 369 (46%). Additionally, UCR 369 maintained seed protein content under waterlogging conditions, while it decreased by 8% in EpicSelect.4 seeds. Overall, UCR 369 was more tolerant to waterlogging stress than EpicSelect.4, with the most apparent effect of waterlogging on yields occurring at the R2 stage due to the high energy demands of the cowpea reproductive process. Our study highlights the importance of selecting cowpea genotypes with greater tolerance to waterlogging stress during the reproductive stage to mitigate the negative effects of waterlogging on seed yield in flood-prone environments. These results provide valuable insights into the mechanisms of cowpea's responses to waterlogging stress and can aid in developing strategies for improving cowpea yield in waterlogged environments, which are expected to become more frequent due to climate change.

Chemical, Anatomical, and Productivity Responses of Cowpea (Vigna unguiculata L.) to Integrated Biofertilizer Applications with PGPR, Cyanobacteria, and Yeast

Integrated biofertilizers such as Plant Growth-Promoting Rhizobacteria (PGPRs), cyanobacteria, and yeast can considerably improve the growth, integrity, and overall health of crops, including cowpea. In this study, we assess the benefits of applying microbial fertilizers as an eco-friendly approach to partially substitute chemical fertilizers while maintaining growth and yield characteristics in cowpea plants. We investigated the role of the three microorganisms, Bacillus amyloliquefacien (B), Nostoc mucorum (C), and Saccharomyces cerevisiae (Y), individually and in four possible combinations (B + C, B + Y, C + Y, and B + C + Y) as integrated bio-fertilizers on the microbial enzyme activities, plant growth parameters, and yield characteristics of cowpea. Plants inoculated with B + C + Y mixture resulted in significant improvement in dehydrogenase enzyme activity by 390%, chlorophyll by 180%, plant dry weight by 130%, and in the pod length and dry weight by 68% and 190%, respectively, compared to non-inoculated plants. The grain total carbohydrates increased by 170% over the control due to treatment with B + C + Y. The B + C + Y treatment also positively influenced the anatomy of the terminal leaflet with a 16.6% higher thickness of the midrib zone, 22.6% increase in vascular bundle length, and 42.4% and 33.5% increases in upper and lower epidermal leaf layers, respectively. Additionally, palisade and spongy tissues increased by 36.9% and 26.5%, respectively, compared to the control. An integrated nutrient management program using biofertilizers is recommended for achieving higher yields and environmentally safe cowpea production.

Effect of rhizobia inoculation and seaweed extract (Ecklonia maxima) application on the growth, symbiotic performance and nutritional content of cowpea (Vigna unguiculata (L.) Walp.)

Research efforts to develop alternatives to chemical-based fertilizers for sustainable crop production has led to renewed interest in beneficial soil microbes such as rhizobia and plant growth promoting biostimulants such as the seaweed (Ecklonia maxima). This study assessed the interactive effect of the co-application of seaweed extract with two Bradyrhizobium strains (Inoculant 1 and Inoculant 2) on the growth, symbiotic performance and nutritional composition of three cowpea (Vigna unguiculata (L.) Walp.) genotypes (IT97K-390-2, Songotra and TVU13998) grown under glasshouse conditions. The response of cowpea to the treatments was genotype dependent, such that the combined application of inoculant 2 plus seaweed extract increased nodule dry matter in genotype Songotra, and together with sole inoculant 2 increased the parameter in genotype IT97K-390-2, just as the inoculation plus seaweed extract treatments increased the parameter in genotype TVU13998 when compared to their respective counterparts receiving other treatments. Sole inoculation or inoculation plus seaweed extract treatments increased shoot dry matter in all varieties (2.0 to 7.2 g.plant-1) relative to the control plants receiving sole nitrate (0.5 to 1.2 g.plant-1), sole seaweed extract (0.3 g.plant-1), nitrate plus seaweed extract (1.2 to 1.6 g.plant-1) or the absolute control (0.2 g.plant-1). Due to N2 fixation in the inoculated plants, their leaf δ15N (-2.66‰ to -1.20‰) were markedly lower (p≤0.001) than values recorded by the control plants (+3.30‰ to +510‰) which had no nodules; consequently, leaf N accumulation was greater in the inoculation-based treatments (41.2 to 258.2 mg.plant-1) relative to the uninoculated controls (1.7 to 24.7 mg.plant-1). In most instances, the sole inoculation and inoculation plus seaweed extract treatments increased leaf photosynthetic rates (except for genotype TVU13998 treated with inoculant 1 + seaweed extract), water use efficiency (δ13C) (except in genotype TVU13998) and the concentrations of macro and micronutrients in leaves (except for K in Songotra treated with inoculant 1 or inoculant 1 + seaweed extract as well as Mn in TVU13998 treated with inoculant 1 among others) of the cowpeas relative to the controls. We highlight the potential benefits of the synergistic interactions between rhizobia and seaweed extract for enhancing plant growth and nutrient accumulation in cowpea leaves.

IMPACT OF TILLAGE PRACTICES ON PROPERTIES OF SOIL, EVAPOTRANSPIRATION AND PRODUCTIVITY OF COWPEA IN NIGERIA

<p><strong>Background</strong>: Tillage is one of the major threats to soil health which often results into soil physical degradation if not properly managed. Zero tillage is an alternative option from both economic and environmental protection of our soil resources points of view. <strong>Objective. </strong>To evaluate responses of cowpea (<em>Vigna unguiculata</em>) yield and evapotranspiration to different tillage practices.<strong> Methodology</strong>. The study was conducted in Obafemi Awolowo University, Ile-Ife Osun State, Nigeria using a replicated randomized complete block design with treatments consisting of Zero-tillage (ZT), Reduced tillage (RT), Conventional tillage + Mulch (CT + ML) and Conventional tillage (CT). <strong>Results. </strong>Soil penetration resistance (SPR) increased with the degree of soil manipulation during tillage practices. Penetration resistance (PR) across 15-30 cm in 2019 alone resulted in higher PR of 2.26 MPa for RT compared to 0.71, 0.72 and 0.79 MPa for ZT, CT + (ML and CT), respectively, approximately 218 %, 213 % and 186 % greater in RT than ZT, CT + ML and CT respectively. <strong>Implications. </strong>Cowpea production on sandy loam soil can be optimized with Zero tillage. <strong>Conclusion.</strong> Over a period of two years, ZT practice had the highest profit margin of $ 573, among the practices. </p>

Physiological responses of cowpea simultaneously exposed to water deficit stress and varying light intensities at vegetative and reproductive growth stages

A combination of stresses as it occurs on the field poses more challenges to crop production than individual stress. Crops’ response to single stress also differs from that of combined stresses. The morpho-physiological responses of two cowpea varieties (IT89KD-288 and IT99K573-1-1) to a combination of stresses (water deficit stress and high light intensity) were investigated at different growth stages. Three levels of light intensities (L3: 259 Lux- 36%, L2: 394 Lux-55% and L1: 710.2 Lux-100%) were imposed using one, two and zero layer(s) of the net, respectively, while, water deficit stress at four levels (W1: no water stress; 0-5 bars, W2: moderate water stress; 5-15 bars, W3: moderately-severe; 15-40 bars and W4: severe water stress; 40 -70 bars) was imposed differently at vegetative and reproductive growth stages. Data were collected on the cowpea yield, Leaf Temperature (LT), Chlorophyll (C), Photosynthesis (P), Stomatal Conductance (SC) and Canopy Transpiration Rate (CTR). Exposure to W4 under L1 considerably reduced cowpea yield by 80% compared to those grown under L3 and full watering. Reduced light intensity enhanced cowpea grain yield irrespective of water deficit stress and IT89KD-288 was superior to IT99K573-1-1. Reduction in light intensity also increased the SC from 55.18 in L1 to 76.88 in 36 % L3. Full light intensity without water stress (100% light intensity), increased C content, while severe water stress reduced the C content and CTR. Photosynthesis was, however, reduced under low light intensity compared to 100% light intensity. It was also observed that water deficit stress imposed at the reproductive stage did not affect P, CTR and SC unlike that of the vegetative stage. In conclusion, reduced light intensity enhanced cowpea tolerance to water deficit and increased yield. Cowpea response was dependent on growth stage, variety and severity of stress.

Cowpea Growth and Nitrogen Fixation Performance under Different Mulch Treatments

Mulching is regarded as the most important of the three conservation agriculture principles in increasing crop yield in the short term. Thus, the main objective of this study was to investigate the impact of mulch type and mulch application rate on biological nitrogen fixation (BNF), physiological and yield responses of cowpea. A multi-locational (two locations) and multi-seasonal (two seasons) study was carried out under rainfed conditions in the Limpopo Province of South Africa. Three mulch types (Moringa oleifera stems; Moringa oleifera leaves and twigs; and Vachellia karroo leaves and stems) were uniformly spread on the surface at four rates (0, 3, 6, 9 t/ha). The application of mulches, regardless of the rate and type, improved cowpea chlorophyll content and agronomic parameters, such as stem diameter and plant height. Grain yield at Syferkuil responded to the mulching effect in both seasons, while at Ofcolaco, differences were only observed in one of the seasons. Cowpea under control discriminated against 15N more than under mulched treatments, resulting in more than 70% of the nitrogen being derived from air compared to 50% in mulched plots. This study demonstrated that organic surface mulches improved the physiological responses of cowpea and that organic surface mulches with a lower C:N ratio significantly reduced BNF.

Cowpea transcriptional reprogramming during two different physiological moments of root dehydration

The transcriptomes of two distinct physiological moments of root dehydration condition were scrutinized in cowpea. The RD25 (first 25 min after root dehydration imposition) physiological data did not indicate significant alterations. For the other treatment, 150 min under root dehydration (RD150), all physiological data indicated that the studied cultivar was under stress. The physiological differences between RD25 and RD150 reverberated in the respective transcriptomes. The sets of in silico differentially expressed isoforms showed specificity for each treatment time. The comparison of T25 | UR [up-regulated transcripts in T25 (RD25 vs. Cont25)] vs. T150 | UR [up-regulated transcripts in T150 (RD150 vs. Cont150)] enriched GO terms (associated with abiotic stresses), despite certain similarities, showed us that they were associated with the respective physiological moments. Concerning gene families, a large portion of those present in the T25 | UR were associated with signaling processes; for T150 | UR, a miscellany of families (from transcription factors to nonenzymatic proteins) was observed. The plotting of transcriptomics data in the KEGG Pathway database indicated a change in the topology of activated metabolic modules in T25 | UR vs. T150 | UR. For the latter, it was observed that most activated modules were associated with specialized metabolism. C2H2 and BPC1 transcription factors (TFs) sites were enriched at T25 | UR and T150 | UR gene promoters, suggesting the importance of these TFs for cowpea response to root dehydration. Our work provides insights into specific molecular actors and pathways, enhancing our global understanding of cowpea stress response.

Response of Inorganic Fertilizers, Crop Residues, Organic Manure and Bio-fertilizer on Soil Health and Yield attributes of Cowpea (Vigna unguiculata L.)

During Kharif season 2021-22 at the central research farm of the Department of Soil Science and Agricultural Chemistry in Naini Agriculture Institute research was carried out on response of cowpea by applying crop residues, organic manure, inorganic and Bio-fertilizers for effective crop growth. The experiment trial was conducted based on Randomize Block design with 9 treatments and 3 replications. The results revealed that the soil bulk density ranged from 1.15 to 1.45 Mg m-3, particles density ranged from 2.04 to 2.44 Mg m-3, and pore space ranged from 40.69% to 45.62%. The pH ranged from 6.63 to 7.27, E.C from 0.146 to 0.253 dS m-1, Soil Organic carbon ranged from 0.344 to 0.627%, Available Nitrogen ranged from 142.38 to 248.39 kg ha-1, Phosphorus ranged from 15.28 to 35.37 kg ha-1, Potassium 179.63 to 240.67 kg ha-1 respectively. T3 was shown the best yield compared to respective treatments which is 19.45 q ha-1 Thus, it indicates that the process of integrated nutrient management may be a better option for the physical and chemical condition of the soil to achieve better growth and yield attributes for Cowpea.

Growth and Yield Responses of Cowpea (Vigna unguiculata L.) as Influenced by Crop Geometry and Nutrient Management Practices

Background: Inclusion of legume with cereal as an intercrop ensure crop nutrition and enhanced soil quality. Combine application of organic manure with inorganic fertilizer minimizes the soil hazard and improves crop productivity in a significant manner. Methods: The experiment on Kharif maize +cowpea intercropping system was carried out at ‘Jaguli Instructional Farm’ of Bidhan Chandra Krishi Viswavidyalaya, Nadia, under the New Alluvial Zone of West Bengal in 2019-2020 to investigate the influence of crop geometry and nutrient management practices on growth and yield responses of legume (cowpea). The experiment was laid out with a split-plot design. The main plot had five crop geometry and a sub plot comprised five nutrient management practices, which were replicated thrice. Result: From the pooled data of two years experiment, the intercropping system of 1M:1C (Maize: Cowpea) (C3) perform better in respect of growth attributes, viz., leaves plant-1, LAI, branches plant-1 and CGR; yield reflecting attributes viz., pods plant-1, pod length, pod and forage yield of cowpea (1.30 and 5.49 t ha-1) and crop (maize) equivalent yield of cowpea (1.76 t ha-1) although the maximum values were attained from sole cowpea treatment (C2). Nutrient management practices with the application of 75% N as chemical + 25% N as organic with seaweed application (N2) recorded greater growth and yield viz., pod, forage and crop (maize) equivalent yield (1.51, 6 and 2.01 t ha-1), respectively. Total nodules plant-1 were significantly influenced by crop geometry and nutrient management, whereas the total chlorophyll content of cowpea was significantly varied with nutrient management. Regression studies depicted the negative functional relationship between pod yield and canopy temperature, whereas the relationship between intercepted photosynthetic active radiation (PAR) and pod yield was positive.

Yield and profitability responses of cowpea to cropping systems and sowing seasons in Vitória da Conquista, Bahia State, Brazil

Cowpea (Vigna unguiculata) crops produce a poor yield in northeastern Brazil compared to the other regions. The goal of this study was to assess the effects of irrigated cropping systems and sowing seasons on cowpea yield and profitability in Vitória da Conquista, Bahia, Brazil. Field studies were performed in four experiments during the rainy and dry seasons during 2016/2017 and 2017/2018, which denoted harvests 1, 2, 3, and 4, respectively. A randomized block design was used for each experiment with four replicates and the following treatments for cropping systems: (1) manual weeding; (2) liming and manual weeding; (3) liming and phosphorus (P) fertilization at sowing, nitrogen (N) and potassium (K) topdressing fertilization, and chemical weed control; (4) liming and P fertilization at sowing, K topdressing fertilization, rhizobia inoculation, and chemical weed control; (5) liming and P fertilization at sowing, N and K topdressing fertilization, rhizobia inoculation, and chemical weed control; and (6) seed pretreatment with cobalt (Co) and molybdenum (Mo), liming and P fertilization at sowing, N and K topdressing fertilization, rhizobia inoculation, and chemical weed control. The technology added to cropping systems increased the number of pods per plant, pod length, seeds per pod, and 100-seed weight, irrespective of the rainy or dry sowing season. Economic analysis, in turn, showed that the technology decreased the total operating cost despite increasing the cost of mechanical operations, inputs, and materials because of the replacement of manual weeding by chemical weed control. However, these costs were not influenced by the sowing seasons. We concluded that technologically enhanced cropping systems, especially systems 4 and 6, improved grain yield and provided greater profitability, which translated into improved economic benefits for farmers. Conversely, the sowing season influenced profitability, which was higher for dry season harvests, when there was less product offered and prices became higher.

Cowpea Genotypic Variations in N2 Fixation, Water Use Efficiency (δ13C), and Grain Yield in Response to Bradyrhizobium Inoculation in the Field, Measured Using Xylem N Solutes, 15N, and 13C Natural Abundance

To evaluate cowpea genotypic differences in response to inoculation with Bradyrhizobium sp. strains BR 3267 and CB756 in the field, 15 genotypes were assessed for N2 fixation using 15N natural abundance and assays of xylem N solutes (ureides, nitrates, and amino-N). Carbon isotope discrimination (δ13C) was used as a surrogate for water use efficiency and grain yield determined at maturity. Within each location, the tested cowpeas elicited contrasting responses to inoculation with either Bradyrhizobium strains. For example, inoculating Apagbaala and IT90K-277-2 with strain BR 3267 doubled N-fixed and grain yield at Nyankpala when compared to inoculation of the same genotypes with strain CB756, whereas the inoculation of Padituya with strain CB756 increased those same parameters relative to non-inoculation. Similar contrasting results were also obtained at Savelugu and Gbalahi, where bacterial inoculation with each strain resulted in up to a five-fold increase in N-fixed and a four-fold increase in grain yield depending on the cowpea/inoculant combinations used and the planting location. The main effect of genotype showed that the percent N derived from N2 fixation (%Ndfa) by the test cowpeas ranged between 74.4 and 89.8%, 11.7 and 50.5%, and 71.9 and 90.3% at Nyankpala, Savelugu, and Gbalahi, respectively. The genotypes grown at Savelugu generally exhibited low %Ndfa which was augmented by greater soil N uptake leading to grain yield increases, a finding supported by significant positive correlations when N-fixed and N content were each plotted against grain yield within locations. The inverse relationship between symbiosis and soil N uptake was also supported by negative correlations between xylem nitrate concentration and relative ureide N abundance (RU-N), and between xylem nitrate concentration and %Ndfa measured from 15N natural abundance. Some high yielding genotypes also elicited greater water use efficiency (δ13C), a trait that could be exploited for increased cowpea production in water limiting environments. This study demonstrates the presence of genotypic differences in cowpea response to inoculation in the field and contributes to the literature regarding the factors influencing legume inoculation response in the tropics.