Cowpea Crop Research Articles

Evaluation of Genotypes of Some Cowpea (Vigna unguiculata (L.) walp) Varieties for Resistance to Thrips (Megalurothrips sjöstedti) in Burkina Faso

Aims: Cowpea (Vigna unguiculata (L) Walp.) is one of the most important grain legumes grown in all arid and semi-arid zones of Africa. Its production helps to combat malnutrition and poverty, and contributes to food self-sufficiency. However, its production comes up against numerous abiotic and biotic constraints, including floricultural insects such as thrips (Megalurothrips sjöstedti), which are small insects. They belong to the order Thysanoptera, family Thripidae, and cause considerable damage to cowpea crops, especially at flowering time. The aim of this study was to evaluate the behavior of eight lines from Burkina Faso compared with the thrips-resistant line (TVx3236) from the IITA collection (Nigeria). Methodology: A completely randomized block design with three replications in two trials (PT treated plot and PNT untreated plot) was used for the experiment. Results: Results showed that some varieties were resistant to thrips, while others were susceptible. The resistant genotypes were those with a low number of thrips per flower and high pod production. On this basis, KVx780-1 is the best genotype compared with KVx780-6 for varieties currently being popularized. Nafi variety is the best compared with the varieties popularized in 2012 (Nafi, Gourgou, Komcallé and Tiligré). Conclusion: In the case of the varieties that were previously popularized, the results confirmed the susceptibility of KN-1 variety, the tolerance of variety KVx165-14-1 and the resistance of the variety TVx3236.

Exploring the Pollinator Community: Diversity and Abundance of Flower-Visiting Insects on Cowpea in Bilone, Obala, Cameroon

Aims: Investigations in cowpea fields allowed the characterization of the community structure of flower-visiting insects. Study Design: Seeds were sown in 15 plots (6x5.5 m each). Place and Duration of Study: Campus of Obala Higher Institute of Agriculture and Management (OHIAM), Bilone agroecological farm (Obala-Cameroon), from May to June 2016 and 2017. Methodology: Insects were identified in-situ or captured and stored in papillotes (Lepidoptera adults) or labelled vials containing 70° ethanol (other insects). Abundances allowed the determination of 11 alpha diversity indices. Beta diversity was tested using Bray-Curtis dissimilarity index and the correlation between species occurrences. Results: A total of 929 specimens belonged to five orders, 10 families, 13 species were recorded. Hymenoptera was the most family-rich and abundant (four families, 94.3% of the collection) followed by Diptera and Lepidoptera (two families each). Neuroptera and Orthoptera (one family each). Apidae was the most species-rich and abundant (three species; 72.9%), then Formicidae (one, 10.1%), Megachilidae (two; 9.8%). Apis mellifera (Apidae) was the most abundant (35.5%), then Xylocopa olivacea (Apidae) (22.3%), Amegilla calens (Apidae) (15.1%), Myrmicaria opaciventris (Formicidae) (10.1%), and Megachile (Chalicodoma) cincta (Megachilidae) (8.2%). The afrotropical useful predator Ascalaphus africanus (Ascalapidae) and the phytophagous pest Pteropera carnapi (Acrididae) were recorded. Exotic myasigenic species Calliphora vicina (Calliphoridae) and Musca domestica (Muscidae) were recorded. Acrididae, Nymphalidae and Pieridae cumulatively represented 3.1% pest species in the collection. Assemblages showed low species richness, high species diversity, and highly even community. Numbers of simply abundant species were close to that co-dominants. A negative correlation was noted between Acraea acerata (Nymphalidae) and Apis mellifera adansonii (Apidae), Ap. mellifera and Calliphora vicina (Calliphoridae), Ap. mellifera and Synagris conuta (Vespidae). Several positive correlations were recorded. Conclusion: In Bilone, results highlighted the importance of flower-visiting insects for the cowpea pollination and crop yield. Species were moderately abundant and assemblages functioned on the base of niche partitioning nomocenosis (log-linear model) of more or less disturbed environments with strong competition between pioneer species for the available resources.

On-farm Productivity and Profitability of Paired-Row-Rice Diversified Cropping System in West Coast Plains and Ghat Region of India

Globally diversification of rice based cropping system buildups ecosystem resilience and food security. In the summer season, weed growth and water availability are a major problem for rice cultivation; it can be managed with the help of intercropping. A field experiment was carried out during summer season of 2023-24 at Integrated farming system research station, Karamana, Thiruvananthapuram to study the production potential of diversified intercrops in paired row planted rice in summer fallows of double cropped lowland rice fields. The field experiment was laid out in a randomized, completely block design with 10 treatments and three replications. The treatments were T1: Paired row of Rice + Grain Cowpea, T2: Paired row of Rice + Finger millet, T3: Paired row of Rice + Foxtail millet, T4: Paired row of Rice + Proso millet, T5: Sole crop of Paired row Rice, T6: Sole crop of Grain Cowpea, T7: Sole crop of Finger millet, T8: Sole crop of Foxtail millet, T9: Sole crop of Proso millet, T10:Fallow. Among the treatments, higher number of tillers m-2 and leaf area index were in the sole crop of paired row rice (T5). Among the yield attributes, rice had the highest number of productive tillers m-2, grain yield and straw yield in the sole crop treatment(T5). Sole crop treatments performed best in terms of growth and yield attributes than their intercropping treatments. The highest yield (5.85 t ha⁻¹) was observed in the sole crop of rice (T5), which was superior to all other treatments. The yield recorded in T1 (paired row of rice + grain cowpea) and T4 (paired row of rice + proso millet) were statistically at par and significantly higher than T3 (paired row of rice + foxtail millet). Paired row of rice + grain cowpea (T1) recorded the highest monetary advantage index of ₹ 55820 ha-1. The analyzed data showed that T5(sole crop of paired row rice) resulted in 8 to 15 per cent grain yield increase over intercropping treatments. It can be concluded from the study that among the intercrops, grain cowpea can be recommended for diversification in paired row planting of rice in summer fallows for higher productivity and profitability.

The circadian clock regulates receptor-mediated immune responses to an herbivore-associated molecular pattern.

Plants activate induced defenses through the recognition of molecular patterns. Like pathogen-associated molecular patterns (PAMPs), herbivore-associated molecular patterns (HAMPs) can be recognized by cell surface pattern recognition receptors leading to defensive transcriptional changes in host plants. Herbivore-induced defensive outputs are regulated by the circadian clock, but the underlying molecular mechanisms remain unknown. To investigate how the plant circadian clock regulates transcriptional reprogramming of a specific HAMP-induced pathway, we characterized the daytime and nighttime transcriptional response to caterpillar-derived In11 peptide, in the legume crop cowpea (Vigna unguiculata). Using diurnal and free-running conditions, we found that daytime In11 elicitation resulted in stronger late-induced gene expression than nighttime. Plants with a conditional arrhythmic phenotype in constant light (LL) conditions lost time-of-day dependent responses to In11 treatment, and this was associated with arrhythmic expression of circadian clock core transcription factor Late Elongated Hypocotyl VuLHY1 and VuLHY2. Reporter assays with VuLHY homologs indicated that they interact with the promoter of daytime In11-induced Kunitz Trypsin Inhibitor (VuKTI) via a canonical and a polymorphic CCA1/LHY Binding Site (CBS), consistent with a mechanism of direct regulation by circadian clock transcription factors. This study improves our understanding of the time-dependent mechanisms that regulate herbivore-induced gene expression.

Cryopreservation Protocol for Cowpea Pollen Storage

BACKGROUND: Long-term storage of cowpea pollen is important for the fertilization of spatially or temporally isolated female parents, especially during cowpea crop improvement and wide hybridization programs. OBJECTIVE: Experiments were conducted to determine pollen longevity at different storage temperatures and to develop a cryopreservation protocol for pollen of different cowpea accessions. MATERIALS AND METHODS: The investigation was carried out at the Research Farm of ICAR-NBPGR, New Delhi, India, during the kharif (rainy) season of 2022. Pollen viability was studied after storage for 1, 3, 6, 12 and 24 h, 1 and 2 weeks and 1, 3 and 5 months at three different temperatures (4, -20 and -196 ºC). RESULTS: Fresh pollen viability ranged from 78 to 91 %. The optimal pollen moisture content was 12-14 % and the optimal air desiccation period under the laminar air flow chamber (22±1 °C) was 5 min for subsequent preservation at -196 °C. Pollen viability was lost completely at 4 and -20 °C after 1 and 2 weeks of storage, respectively. Pollen stored in liquid nitrogen (-196 ºC) retained vaiblity similar to that of fresh pollen for > 5 months storage. Pollination using cryostored pollen resulted in normal fertilization. CONCLUSION: This finding opens a gateway for cowpea haploid germplasm conservation and wide hybridization programs.

Research on Resistance Monitoring, Risk Assessment, and Mechanisms of <i>Megalurothrips usitatus</i>

<i>Megalurothrips usitatus</i>, also known as common thrips or cowpea thrips, is a widely distributed and highly destructive pest, primarily infesting legume crops. Due to its short generation cycle, high reproductive capacity, and concealed lifestyle, the effectiveness of chemical pesticide control has been continuously diminishing with the modernization of agricultural production and the extensive use of pesticides. <i>Megalurothrips usitatus</i> has gradually developed resistance to various commonly used pesticides, with resistance levels increasing year by year, thus exacerbating the difficulty of pest management and causing significant economic losses to agricultural production. Scholars, both domestically and internationally, have conducted in-depth research using methods from morphology, molecular biology, and ecology, showing that there are three main causes of pest resistance: enhanced detoxification enzymes, reduced sensitivity at target sites, and decreased cuticle penetration. These findings provide a wealth of theoretical support for resistance monitoring and management. The resistance of <i>Megalurothrips usitatus</i> to multiple pesticides is not only a local issue but also affects global agricultural sustainability. Research on the monitoring, risk assessment, and mechanisms of resistance in <i>Megalurothrips usitatus</i> contributes to prolonging the effective use of pesticides, improving control outcomes, and enhancing both the yield and quality of cowpea crops. These studies also provide a scientific basis for developing more effective control strategies and ensuring sustainable agricultural development.

Functional response and predatory potential of Neoseiulus newsami (Acari: Phytoseiidae) against Megalurothrips usitatus (Thysanoptera: Thripidae)

Megalurothrips usitatus, is an important pest of cowpeas Vigna unguiculata, that causes severe damage to cowpea crops in Southeast Asia and Hainan Province in China. Neoseiulus newsami is a natural enemy of M. usitatus that was first reported from Ledong Li Autonomous County, Hainan, China. Here, we evaluated the potential of N. newsami as a biocontrol agent for use against M. usitatus. In laboratory tests, N. newsami showed a similar rate of attack on this pest as did the better-known species Neoseiulus barkeri. The functional response curve of N. newsami fed M. usitatus showed that more 1st instar prey were consumed by N. newsami at higher prey densities, indicating a Type III functional. The maximum attack coefficient (a) was 0.063 ± 0.011 and the handling time per consumed prey (Th) was 0.58 ± 0.09. The maximum attack rate (T/Th) was 41.37. Neoseiulus newsami showed higher predation and oviposition rates than did N. barkeri or Neoseiulus cucumeris. Our results suggest that N. newsami has a higher predation capacity against M. usitatus.

Effect of Different Fertilizers and Approaches on Nutrient Use Efficiency and Economics of Aerobic Rice Under Rice-Cowpea Cropping Sequence in Ecological Conditions of Karnataka, India

At the University of Agricultural Sciences, GKVK, Bengaluru, a field experiment was conducted in 2015-16 and 2016-17 to examine the impact of fertigation on the yield, nutrient usage efficiency, and economics of aerobic rice in an aerobic rice–cowpea cropping sequence. In a randomized block design, hybrid rice was tested in aerobic conditions with 16 treatments that were reproduced three times. The results indicated that significantly higher grain (62.98 q ha-1) and straw (85.26 q ha-1) yield of rice was recorded in 100% STCR dose through WSF at 8 DI. Similarly higher NRn (3.50 kg q-1) and NRp (0.86 kg q-1) of grain production in 100% STCR dose with WSF at 8 DI on contrary, higher NRk of 2.27 kg q-1 was noticed in 100% STCR with WSF at 4 DI. While higher AUE-N (32.51 kg kg-1), AUE-P (65.02 kg kg-1) and AUE-K (65.02 kg kg-1) were recorded in 30% RDF with WSF at 8 DI. The higher ACRE-N (78.60 %) was recorded with 100% RDF with WSF at 8 DI and higher ACRE-P (44.40%) was recorded with 30% RDF with WSF at 8 DI. Notably higher ACRE-K (132.51%) was recorded in 30% STCR with WSF at 8 DI. However, supplement of 30% STCR dose with WSF at 8 DI obtained notably higher IUE-N (35.05 kg kg-1), IUE-P (163.27 kg kg-1) and IUE-K ( 60.11 kg kg-1). Significantly higher PFP-N, P and K (261.23, 522.46 and 522.46, respectively) were recorded in 30% RDF with WSF at 8 DI. Among all treatments, 100% RDF through CF at 4 DI found significantly higher B: C ratio (2.74) during both years of pooled data.

Budgeting of Primary Nutrients in Soil under Rice-cowpea Cropping Sequences in Alfisols

A field experiment was undertaken at University of Agricultural Sciences, GKVK, Bengaluru, Karnataka, India to study the primary nutrients budgeting in rice-cowpea cropping system in an alfisols. Hybrid rice was tested under aerobic condition during Kharif 2015-16 and 2016-17 with 16 treatments replicated thrice in randomized block design. Notably maximum grain (62.98 q ha-1) and straw (85.26 q ha-1) yield of rice was registered in treatment, which received 100% STCR dose through WSF at 8 DI. Rice has exhibited a notably higher total uptake of N, P, and K in the treatment with 100% STCR dose through WSF at 8 DI (220.68, 44.97, and 137.41 kg N, P, and K ha-1, respectively). In fertigation with 100% RDF through WSF at 8 DI, a significantly greater seed yield (12.94 q ha-1) and haulm yield (26.17 q ha-1) of cowpea were observed. At 4 DI, 100% RDF through WSF showed a closely higher total uptake of N, P, and K by cowpea (68.94, 14.67, and 61.39 kg N, P, and K ha-1, respectively). The maximum net positive balance (148.42 kg N ha-1) was noticed in 100% RDF applied through WSF at 8 DI and minimum net positive balance 53.86 kg N ha-1 was recorded in 100% RDF-CF. During 2016-17, after the completion of second year residual crop cowpea, the maximum net positive balance (148.42 kg N ha-1) was noticed in 100% RDF applied through WSF at 8 DI and minimum net positive balance 53.86 kg N ha-1 was recorded in 100% RDF-CF. The maximum net positive balance (38.27 kg P2O5ha-1) was recorded in 100% STCR dose -WSF 8 DI and minimum net negative balance (15.70 kg P2O5 ha-1) was recorded in 100% RDF-CF. The maximum net positive balance of potassium (98.27 kg K2O ha-1) was recorded in 100% RDF-WSF 4 DI and minimum net positive balance (24.61 kg K2O ha-1) was recorded in 100% RDF-CF 8 DI treatment.

Residual Effect of Water Soluble Fertilizers on Productivity and Nutrients Uptake of Cowpea in Aerobic Rice-cowpea Cropping Sequence under Fertigaton

A field experiment was under taken at University of Agricultural Sciences, GKVK, Bengaluru, Karnataka state, India to study the residual effect of fertigation of water soluble fertilizers on productivity and nutrients uptake of cowpea under aerobic rice-cowpea cropping sequence during Kharif 2015-16 and 2016-17 with 16 treatments replicated thrice in randomized block design. Significantly higher plant height (58.47 cm), number of branches plant-1 (11.71) and total dry matter accumulation plant-1 (70.60 g) were recorded in fertigation with 100% RDF through water soluble fertilizer at 8 DI. Likely, similar treatment 100% RDF through water soluble fertilizer at 8 DI was recorded significantly higher number of pods plant-1 (16.58), pod length (16.67 cm), seeds per pod (16.10), test weight (11.93 g), seed yield (12.94 q ha-1) and haulm yield (26.17 q ha-1). While higher total uptake of N, P and K by cowpea (68.94, 14.67 and 61.39 kg N, P and K ha-1, respectively) was recorded in 100% RDF through water soluble fertilizers at 4 DI (T5) than all other treatments. 100% RDF through WSF at 8 DI (T8) was recorded notably higher total Ca, Mg and S uptake by cowpea (50.71, 24.71 and 12.09 kg Ca, Mg and S ha-1, respectively). Significantly higher uptake of total Fe, Zn and Cu by cowpea crop (680.23, 91.30 and 38.27 g ha-1, respectively) was recorded with 100% RDF through water soluble fertilizers at 8 DI (T8). Total uptake of Mn was recorded higher by cowpea was observed (181.67 g ha-1) in 100% STCR dose through water soluble fertilizers at 4 DI (T11).

Changes in root nodules dynamics under mixed cropping with varying nutrient management of berseem crop and succeeding fodder cowpea

Intercropping is a sustainable way to achieve the growing demands for food and fodder of expanding population of tropical areas. Combined application of nutrient sources along with inclusion of fodder crops in cropping system will influence soil as well as plant characteristics above ground as well as below it. These sustainable approaches may increase nutrient use efficiency by rhizosphere management at soil and plant level giving better understanding of soil plant atmosphere continuum (SPAC). The present study was conducted to evaluate the effect of nutrient management and seed ratios on dynamics of root nodules of berseem as well as succeeding crop cowpea at Agronomy Research farm, National Dairy Research Institute, Haryana, India. Intensive root studies had been done regarding root parameters in berseem as well as residual succeeding crop cowpea in this research. The study revealed that 100%RDF(Recommended dose of Fertilizer)+PGPR (Plant Growth Promoting Rhizobacteria) had given maximum number of nodules (118.60) and other traits for three cuttings in terms of nutrient management and sole berseem in terms of seed ratios number of nodules (112.92), whereas 50%RDF (Recommended dose of Fertilizer) +50% FYM (Farm Yard Manure)-(62.5) and sole berseem (54.30) at harvest had shown better results in terms of residual activity on roots nodules of succeeding crop cowpea where number of nodules (62.5) and fresh wt. of root nodules (622.1 mg) at harvest in 50%RDF + 50% FYM. This research revealed that employing organic sources of nutrients like FYM (Farm Yard Manure) and biofertilizers like PGPR (Plant Growth Promoting Rhizobacteria) along with inorganics in correct proportions enhances the root traits of leguminous fodder crops and reduce sole dependency on harmful agricultural inputs. Hence, this would fulfill the long-term nutritional requirement of crop and preserve crop status in terms of quality and quantity.

Effect of Eighteen Years of Continuous Crop Residue Application on Crop Yields, Soil P Fractions, and Crop P Uptake in Conservation Tillage Under Semi-Arid Tropical Rainfed Conditions

The continuous use of crop residue in soil can enhance the crop yield and potential availability and mobility of P fractions to crops in conservation tillage. A field experiment was conducted to assess the long-term effects of surface crop residue applications on soil P fractions and their relationship with P uptake and crop yields. Field experiment was conducted at ICAR-Central Research Institute for Dryland Agriculture, Hyderabad, India during 2005 to 2022. The experimental treatments applied were: T1 - no crop residue application, T2 - application of crop residue @ 2 t ha-1, T3 - application of crop residue @ 4 t ha-1, and T4 - application of crop residue @ 6 t ha-1 in conservation tillage. The test crops viz. sorghum (Sorghum vulgare) and cowpea (Vigna unguiculata) were grown in a yearly rotation every year in the kharif season in conservation tillage. The results of the long-term study revealed that the per cent increase in sorghum (Sorghum vulgare) grain yield with the application of crop residue at the rate of 2, 4 and 6 t crop residue ha-1was to the tune of 7.9, 16.1 and 26.0%, respectively over no crop residue application. Similarly, the per cent increase in the cowpea (Vigna unguiculata) seed yield was to the extent of 25.2, 43.0 and 64.1% in 2, 4 and 6 t ha-1, respectively over no crop residue application. The sorghum and cowpea stover yield also significantly (p=0.05%) increased with the added levels of the crop residue. Significantly higher P uptake by sorghum and cowpea was recorded in 6 t crop residue ha-1 as compared to the other crop residue treatments. Results of the current study also showed the significant positive response of long-term crop residue application on the P fractions viz., water-soluble phosphorus (WS-P), aluminum bound P (Al-P), iron bound P (Fe-P), calcium bound P (Ca-P) and reductant soluble P (RS-P), and on available P and total P in soil as compared to no crop residue application. The average percent contribution of P fractions toward the sum-total of extracted P was in the order: Fe-P (30.8%)>RS-P (30.7%)>Al-P (24.2%)>Ca-P (9.4%)>WS-P (4.8%). The WS-P and Al-P were found to be the P fractions indicating their specificity by cowpea crop, and WS-P and Ca-P were found to be P fractions indicating their specificity by sorghum crop. The results of the present study will be highly useful in understanding the effect of crop residue application in conservation tillage on the P fractions and their contribution toward P uptake and crop yields.

The Effects of Organic Fertilizers and NPK on Growth and Yields of Cowpea (Vigna unguiculata. L) in Kano Plains Kisumu, Kenya

Excessive use of inorganic mineral fertilizers as an agronomic practice has resulted in the depletion of soil organic matter of soils of many regions thereby rendering such soils infertile and unable to maintain sustainable production. The use of organic amendments provides the immediate strategy for compensating for soil carbon depletion thereby reducing land degradation. The purpose of this study was to evaluate the effects of six organic amendments on the growth and yield of Cowpea (Vigna unguiculata L) as compared to the conventional use of inorganic fertilizer NPK. The organic amendments were Boom Max, Ecoplanting, Evergrow, Dung slurry, Filter mud, and Market waste slurry applied to the soil at 8.33 t/ha against NPK (9:15:20) at 250 kg/ha. The experiment was laid in a RCBD. Data on growth and yields was collected on 10 tagged plants per plot. The results showed differences among treatments. Mature composts (Boom Max, Ecoplanting, and Evergow) resulted in a significantly (p< 0.05) higher germination percentage (53.49% on average) compared to that of Filter mud (41.50%) and the slurries (34.18% on average) while all the composts resulted in 25% higher number of branches on the average in season two as compared to the bio-slurries. In season three, Boom Max gave the highest germination percentage (41.02%) which was significantly higher than those of Evergrow (29.80 %), Filter mud and Dung slurry (27.18% on average) and NPK and Market waste slurry (5.64% on average) but not different from that of Ecoplanting. Five of the amendments had significantly better germination rates than NPK by an average of 20%. There were no significance differences (P≤0.05) in growth parameters between the mature composts and the NPK fertilizer, suggesting that the mature composts were equally efficient in nutrient supply to the crop as did the NPK fertilizer for plant growth. The application of organic amendments produced significant improvements in fresh leaf yields of the cowpea crop, with the highest yield recorded from the Boom Max applied plot (5781 kg on average), which was not different from others in seasons one and three but significantly different from that of NPK in season three. It can be concluded that depending on choice or type of amendment, organic manures are capable of producing similar or better results of crop growth and yields as the inorganic fertilizers.

ETUDE DE LEFFICACITE DES BIOPESTICIDES A BASE DE GRAINESDE NEEM ET DELENTOMOPATHOGENEBEAUVERIABASSIANA(BALS.) VUILL.POUR LA GESTION DES PRINCIPAUX INSECTES RAVAGEURS DE LA CULTURE DU NIEBE DANS LA REGION DE MARADI AU SAHEL

The insect pests of cowpea, Vignaunguiculata L. Walper, is one of the constraints which affect the cultivation this crop in Africa. The pod sucking bug Clavigrallatomentosicollis(Stål), the flower thripsMegallurothripssjöstedti(Trybom) and the pod borer Marucavitrata(Fabricius) are the main insect pests whose damage causes considerable yield losses on cowpea crop. In this study, neem Azadirachtaindica based biopesticides and the entomopathogenBeauveriabassiana(Bals.) Vuill were tested todeterminetheir efficiency in the management of cowpea insect pests. The trials were established in a farming environment with producers in 15 villages of the Maradiregion during three consecutive cropping seasons 2020, 2021 and 2022. The experimental design is the Fisher block with 4 treatments (Neem grain, B. bassiana, Chemical pesticide and the control without treatment) and two repetitions per site. The results for this studybiopesticide treatments (Neem grains and entomopathicfungus B. bassiana) reduced the insect pest damageof 73.21% and a yields increase of 104.12% compared to the control treatment. . Neem was effective as the synthetic chemical pesticide in the management of insect pests as it reduced the populations of M. sjöstedti, M. vitrata and C. tomentosicollis by 67.29, 70.57 and 71.26%respectively. This Neem biopesticide resulted a yield increase of 140.33% on cowpea for the three years of the study. Thus, for low-income producers, neem is an available resource that can constitute an effective and ecological alternative for managing cowpea insect pests in the Sahel.

Integrated Management of Stem and Root Rot of Cowpea Caused by Macrophomina phaseolina (Tassi.) Goid. using Fungicides, Bioagents and Organic Manures

Background: Cowpea crop is affected by various biotic and abiotic stresses which are responsible for its poor quality and low yield resulting in severe economic losses. Among the root diseases, stem and root rot caused by Macrophomina phaseolina is an important disease causing the yield losses ranging from 50-55 per cent. So, there is a need to formulate suitable management practices against root rot. Methods: Field experiment was laid-out in a randomized complete block design with three replications at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad during rabi 2021-22 and 2022-23 to determine the efficacy of economically viable and effective fungicides, bioagents and organic manures against stem and root rot of cowpea. The per cent disease incidence and yield per hectare were taken into consideration for statistical analysis. Result: In laboratory experiments, it was found that, the seed dressing fungicides mancozeb 50% + carbendazim 25% WP and carboxin 37.5% + thiram 37.5% DS were the most effective against M. phaseolina. Similarly, among the bioagents tested, T. harzianum was the most effective followed by T. Viride and P. fluorescens. A two-years evaluation of nine integrated treatment modules for rabi seasons revealed that, seed treatment with carboxin 37.5% + thiram 37.5 % WS resulted in the lowest disease incidence and the highest grain yield, 100 seed weight and B:C ratio. Cowpea stem and root rot incidence was increased with soil temperature and decreased with soil moisture.

COPING STRATEGIES ON CLIMATE VARIABILITY AMONG COWPEA FARMERS IN KWARA STATE, NIGERIA

<p><strong>Background.</strong> The unstable climatic conditions can no longer be predicted by farmers. The unpredictability intensity of temperature and pattern of rainfall in cowpea production has affected the farmers’ decision on production practices and general productivity. Therefore, farmers are beginning to improvise on management practices to avert the effects of climate change to remain relevant and profitable in the business of cowpea production. <strong>Objective.</strong> To examine the farmers’ coping strategies used against the effects of climate variability for cowpea production in Kwara State, Nigeria. <strong>Methodology.</strong> A multistage sampling technique was used to select 120 cowpea-based farmers. A structured survey questionnaire was used to collect primary data. Data were analysed with frequency, percentage, mean, and standard deviation while Pearson Product Moment Correlation was used to ascertain the relationship between socioeconomic characteristics and copying strategies used by farmers. <strong>Results.</strong> Majority (79.2%) of the respondents experienced high adverse effects of climate variability including abnormal rise in temperature (76.7%), irregular/unpredictable rainfall patterns (51.7%), and excessive rainfall (37.5%) on cowpea crop. The leading coping strategies used by farmers were use of fertilizer (x̄=2.73), herbicides (x̄=2.72), and planting early maturing variety (x̄=2.51). Farmers were mainly hindered by adequate irrigation facilities (x̄=1.72), inadequate access to extension services (x̄=1.66), and high cost of agrochemicals (x̄=1.60). Result education, cowpea farm size, years of experience in cowpea farming, membership in farmers group, and additional sources of information on cowpea production showed a positive significant relationship with the choice of coping strategies employed by cowpea farmers against the effects of climate change experienced at p<0.05 level. <strong>Implication.</strong> The study showed that abnormal rise in temperature and irregular rainfall patterns are affecting cowpea production and thus, some socioeconomic attributes significantly supported farmers’ choice of coping strategies employed against the effects of climate change and variability. <strong>Conclusion.</strong> The use of agrochemicals and cultivation of early maturing variety has played critical roles in coping with adverse effects of climate variability in cowpea production. </p>

Neoseiulus mites as biological control agents against Megalurothrips usitatus (Thysanoptera: Thripidae) and Frankliniella intonsa (Thysanoptera: Thripidae) on cowpea crop: laboratory to field.

Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae) and Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) have been detrimental to cowpea production in many countries. Laboratory experiments were conducted to determine the prey stage preference and functional response of 2 predatory mites species, Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae), and Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), towards 2 thrips species (TS), M. usitatus, and F. intonsa, at varying densities and life stages on cowpea. Results shown that Neoseiulus species had a preference for different life stages of prey. Neoseiulus barkeri consumed more M. usitatus nymphs, while N. californicus consumed more F. intonsa (second-instar nymphs). The functional response of the 2 Neoseiulus spp. to nymphs of 2 TS was Type II on cowpea. The higher attack rate coefficient (a') and shorter handling time (Th) values were found on N. barkeri against M. usitatus, and a similar trend was found for those in N. californicus against F. intonsa. Field-caged trials were conducted to evaluate the effectiveness of Neoseiulus spp. in controlling 2 TS. The results have shown that Neoseiulus spp. was effective in controlling the 2 TS, with varying control efficacies at high or low release rates. The study provided valuable information on using Neoseiulus spp. as biological control agents against M. usitatus and F. intonsa in cowpea crops.

Emerging threat to Indian agriculture: Fusarium incarnatum-equiseti species complex as a novel pathogen imperiling bajra, cowpea, finger millet, green gram, moth bean, and soybean crops

India, renowned for its diverse agro-climatic regions and agricultural legacy, relies on staple crops for sustenance. Cereals and Legumes, crucial to Indian agriculture and diet, contribute significantly to food security, economic prosperity, and environmental sustainability. Between August and October 2023, symptoms of grain/pod rot were observed in bajra, finger millet, cowpea, moth bean, green gram, and soybean crops in Uttarakhand. Based on morphological traits and the sequencing of the ITS (Internal Transcribed Spacer), rpb2 (RNA Polymerase II Second Largest Subunit), tef1 (Translation Elongation Factor 1-alpha) genes, the identified pathogens fall within the Fusarium incarnatum-equiseti species complex (FIESC). Pathogenicity tests confirmed the fulfillment of Koch's postulates, establishing the responsibility of the FIESC in grain/pod rot. This study unveils the first incidence of the FIESC causing grain/pod rot in bajra, cowpea, finger millet, soybean, green gram, and moth bean in India. Considering the economic importance of these crops, it is imperative to implement robust disease management strategies to alleviate the adverse effects of these pathogens on agricultural production. The findings underscore the necessity for continued research on emerging diseases to safeguard global crop production and food security.

Effect of Organic Manures on Growth and Yield of Cowpea (Vigna unguiculata L.) Varieties

A Field experiment was conducted during Zaid 2023 at Crop Research Farm, Department of Agronomy, SHUATS, Prayagraj (Uttar Pradesh) on Cowpea (Vigna unguiculata L.). The soil of experimental plot was sandy loam in texture, low in organic carbon (0.452%), nearly neutral in soil pH (7.1), high nitrogen (178.48 kg/ha), medium phosphorous (23.6 kg/ha), medium potassium (231.4 kg/ha). The experiment laid out in a randomized block design consists of three replications along with three cowpea varieties (viz., Kashi Nidhi, Kashi Unnati, Kashi Kanchan) and three solid organic manures (i.e. Poultry manure 2 t/ha, Goat manure 10.5 t/ha, Pig manure 15 t/ha) which were replicated thrice. The results revealed that maximum plant height (52.73 cm), dry weight (15.03 g/plant), crop growth rate (12.57 g/m2/day), number of pods/plant (11.80), number of seeds/plant (11.50), test weight (81.00g), seed yield (2.40 t/ha), stover yield (4.10 t/ha). Maximum net returns (INR 79,515.00/ha) and benefit cost ratio (2.30) which was significantly superior over other treatment T3 (Kashi Kanchan + Poultry manure 2 t/ha). It can be concluded that Kashi Kanchan variety with application of poultry manure 2 t/ha brought about significant improvement in the production and also proven economically viable in cowpea crop.

Assessing the Effectiveness of Neem oil and Microalgae in the Management of Cowpea (Vigna unguiculata L.) Leaf Spot Caused by Alternaria spp.

The current study aimed to assess the effectiveness of neem oil and microalgae in controlling leaf spot caused by Alternaria spp. in cowpea (Vigna unguiculataL.). The research was conducted during the Zaid season of 2022 at the Central Research Field of the Department of Plant Pathology, SHUATS, Prayagraj, Uttar Pradesh, using a Randomized Block Design with three replications and seven treatments. Analysis of variance (ANOVA) was utilized to draw conclusions from the data. Leaf spot disease caused by Alternaria spp poses a significant threat to cowpea crops, resulting in yield losses and decreased plant vigor. An in vivo study was carried out to evaluate the impact of different concentrations of microalgae combined with neem oil at 1% on plant growth parameters and Disease Intensity (%). The application of microalgae @540 grams in various splits and neem oil @1% was done. Among all the treatments, T4 (Microalgae 48gms @5 DAS 96gms@15,45 DAS + Neem oil @1% showed promising results. Notably, the T4 treatment significantly increased plant height (84.63 cm) and the number of branches(10.83) at60DAS. Moreover, an increased numberof nodules per plant (21.44) was observed at 75 DAS, indicating improved root health and nitrogen fixation. Additionally, the treatment led to longer pod length (34.44 cm) in three pickings, suggesting enhanced yield potential. Furthermore, the combined application of microalgae and neem oil resulted in a significant reduction in disease intensity, with a notable decrease of 24.47% compared to untreated plants and those treated with chemicals (Bavistin). This indicates that the use of microalgae and neem oil together effectively suppressed leaf spot disease caused by Alternaria spp. in cowpea, thereby improving plant health and productivity. In conclusion, these findings underscore the potential use of eco-friendly alternatives like microalgae and neem oil for managing leaf spot disease in cowpea cultivation. Further research in this area is recommended for sustainable agricultural practices.