Cowpea Plants Research Articles

Physiological characterization and bioactive compounds of promising accessions of cowpea (Vigna unguiculata L. Walp) in the Peruvian Amazon

Cowpea production in the Peruvian Amazon is increasing due to its ability to adapt to diverse environments, its contribution to soil conservation, and its versatility of uses. This crop is particularly valuable in human nutrition due to its high nutritional quality and nutraceutical properties of its bioactive compounds. The aim of the study was to evaluate the physiology of cowpea plants in accessions PER1005854, PER1005851, and PER12645, under the influence of rice husk mulch, screw tree litter, and oil palm fiber, as well as to determine the bioactive compounds present in the grains. This study aims to promote sustainable cowpea production, expose the nutritional aspects of the grains, and foster their consumption both locally and nationally. The experiment was conducted from November 2022 to March 2023, in Yurimaguas, Loreto, Peru. The application of organic mulches demonstrates a significantly positive impact on the growth of cowpea accessions during their vegetative phase. This effect is possibly attributed to increased water availability, as the mulch reduces soil evaporation. In particular, cowpea accessions PER12645 and PER1005851 exhibit desirable physiological characteristics for grain production, with short cycles of 71 days and higher yields of 1141 and 1125 kg/ha respectively. In contrast, accession PER1005854 is distinguished by its higher biomass production, reaching a value of 14497 kg/ha, a relevant trait for foliage production and its contribution to soil conservation. The bioactive compounds, such as proteins, lipids, and carbohydrates, present in the accessions PER1005854, PER1005851, and PER12645, are similar to those found in other legumes. However, the antioxidant activity of dark tegument cowpeas proved to be superior, particularly highlighted in accession PER12645 (black tegument) with 26.3 μmolTG/g, and in accession PER1005854 (dark red tegument) with 19.5 μmolTG/g. This characteristic is particularly important for consumption, as it is related to the ability to combat oxidative stress in the human body.

Plants attacked above-ground by leaf-mining flies change below-ground microbiota to enhance plant defense.

Root-associated microbiomes play a crucial role in plant responses to biotic and abiotic stresses. Plants can enrich beneficial microbes to increase their stress-relieving ability. Above-ground insect herbivory is among the most detrimental stresses for plants, especially to crop production. However, few studies have explored how root-associated microbiomes respond to herbivores and influence plant-defense functions under herbivory stress. We investigate the changes and functional role of root-associated microbial communities under herbivory stress using leafminer (Liriomyza trifolii) and cowpea (Vigna unguiculata) as a focal system. We did this by using a combination of 16S ribosomal RNA gene profiling and metagenomic sequencing to test for differences in co-occurrence networks and functions between cowpea plants infested and noninfested with leafminers. The results demonstrated that leafminer infestation caused a shift in the rhizosphere microbiome, which was characterized by a significant variation in microbiome community structure and composition, the selection of hub microbes involved in nitrogen (N) metabolism, and functional enrichment related to N metabolism. Notably, nitrogen-fixing bacteria Bradyrhizobium species were actively enriched and selected to be hubs in the rhizosphere. Inoculation with Bradyrhizobium enhanced cowpea performance under leafminer stress and increased protease inhibitor levels to decrease leafminer fitness. Overall, our study characterized the changes of root-associated microbiota between leafminer-infested and noninfested cowpea plants and revealed the mechanisms underlying the rhizosphere microbiome shift that enhance plant performance and defense against herbivory. Our findings provide further support for the notion that plants enrich rhizosphere microbes to counteract aboveground insect herbivores.

Impacts on Soil and Cowpea Plants Fertigated with Sanitary Sewage through Subsurface Drip Irrigation

The application of sanitary sewage using subsurface drip irrigation can mitigate current challenges related to water availability and food production. However, before implementing these techniques, it is crucial to conduct studies to assess their impacts on soil and plants. The objective of this study was to evaluate chemical changes in the soil and the development of cowpeas subjected to sanitary sewage applied by drippers with different flow rates and installation depths. Drippers were positioned at various depths (0 to 30 cm) and operated with flow rates of 1.6 and 3.8 L h−1. Cowpeas were cultivated in pots with clayey soil, using synthetic sanitary sewage based on the maximum limit of nitrogen fertilization. Irrigation management was controlled in terms of soil moisture, which was monitored using TDR probes. The results indicated that reducing the depth of the drippers positively affected grain production and the development of cowpeas. Fertigation with sanitary sewage at greater depths increased soil phosphorus concentrations and base saturation. Dripper depth also influenced soil concentrations of phosphorus, potassium, calcium, and magnesium, while sodium concentrations decreased with greater depth. It is concluded that dripper flow rates did not impact soil chemical parameters or the agronomic characteristics of cowpeas. However, despite nutrient supply at greater depths, the subsurface drip irrigation system proved unsuitable for cowpea production in clayey soil.

Hollow Mesoporous Silica Nanoparticles as a New Nanoscale Resistance Inducer for Fusarium Wilt Control: Size Effects and Mechanism of Action.

In agriculture, soil-borne fungal pathogens, especially Fusarium oxysporum strains, are posing a serious threat to efforts to achieve global food security. In the search for safer agrochemicals, silica nanoparticles (SiO2NPs) have recently been proposed as a new tool to alleviate pathogen damage including Fusarium wilt. Hollow mesoporous silica nanoparticles (HMSNs), a unique class of SiO2NPs, have been widely accepted as desirable carriers for pesticides. However, their roles in enhancing disease resistance in plants and the specific mechanism remain unknown. In this study, three sizes of HMSNs (19, 96, and 406 nm as HMSNs-19, HMSNs-96, and HMSNs-406, respectively) were synthesized and characterized to determine their effects on seed germination, seedling growth, and Fusarium oxysporum f. sp. phaseoli (FOP) suppression. The three HMSNs exhibited no side effects on cowpea seed germination and seedling growth at concentrations ranging from 100 to 1500 mg/L. The inhibitory effects of the three HMSNs on FOP mycelial growth were very weak, showing inhibition ratios of less than 20% even at 2000 mg/L. Foliar application of HMSNs, however, was demonstrated to reduce the FOP severity in cowpea roots in a size- and concentration-dependent manner. The three HMSNs at a low concentration of 100 mg/L, as well as HMSNs-19 at a high concentration of 1000 mg/L, were observed to have little effect on alleviating the disease incidence. HMSNs-406 were most effective at a concentration of 1000 mg/L, showing an up to 40.00% decline in the disease severity with significant growth-promoting effects on cowpea plants. Moreover, foliar application of HMSNs-406 (1000 mg/L) increased the salicylic acid (SA) content in cowpea roots by 4.3-fold, as well as the expression levels of SA marker genes of PR-1 (by 1.97-fold) and PR-5 (by 9.38-fold), and its receptor gene of NPR-1 (by 1.62-fold), as compared with the FOP infected control plants. Meanwhile, another resistance-related gene of PAL was also upregulated by 8.54-fold. Three defense-responsive enzymes of POD, PAL, and PPO were also involved in the HMSNs-enhanced disease resistance in cowpea roots, with varying degrees of reduction in activity. These results provide substantial evidence that HMSNs exert their Fusarium wilt suppression in cowpea plants by activating SA-dependent SAR (systemic acquired resistance) responses rather than directly suppressing FOP growth. Overall, for the first time, our results indicate a new role of HMSNs as a potent resistance inducer to serve as a low-cost, highly efficient, safe and sustainable alternative for plant disease protection.

Morfofisiologia de feijão-caupi sob estresse salino e aplicação de nanobioestimulante de carbono na fase vegetativa

ABSTRACT Several technologies have been implemented to improve plant performance in irrigated crops, and one of them is the use of nanobiostimulants. Therefore, the aim of the present study was to explore the effects of applying different concentrations of a carbon-based biostimulant on the morphophysiology of cowpea plants subjected to varying electrical conductivities of irrigation water. The experiment was performed in a completely randomized design, in a 2 × 6 factorial scheme, with two electrical conductivities of irrigation water (ECw: 0.35 and 4.0 dS m-1) and six concentrations of nanobiostimulant applied through the leaves (0, 80, 160, 240, 320, and 400 mg L-1), with four replications. Growth and gas exchange variables were evaluated 31 days after sowing (V9 stage). Concentrations between 240 and 320 mg L-1 of carbon-based nanobiostimulant promoted greater increases in growth and physiological variables, but they caused decreases in non-photochemical quenching. Water electrical conductivity of 4.0 dS m-1 reduced the number of leaves (17.1%), stem diameter (10.0%), SPAD index (10.3%), net photosynthesis (10.9%), stomatal conductance (46.4%), transpiration (34.5%), instantaneous carboxylation efficiency (22.4%), and photochemical quenching (4.5%); in contrast, it increased the ratio between internal and ambient CO2 concentration (18.0%), leaf temperature (2.9%), water use efficiency (32.5%), and non-photochemical quenching (12.4%). Concentrations of 240 to 320 mg L-1 of the nanobiostimulant enhance the development and gas exchange of cowpea plants under non-stress conditions, whereas the concentration of 240 mg L-1 promotes the maximum increase in plant height under salinity.

Evaluating the Effect of Cowpea Variety on the Insecticidal Response and Antioxidant Enzymes of Callosobruchus Maculatus (Fabricius) Treated with Two Plant Powders

Callosobruchus maculatus (Fabricius), a notorious pest wreaking havoc during the storage phase of cowpea, has remained a serious menace militating against cowpea production in sub-Saharan Africa for years. This study investigated the effects of cowpea varieties [Gombe (GBV) and Sokoto (SKV)] on the insecticidal response and antioxidant enzymes of adult C. maculatus treated with powders of Piper guineense (Schum and Thonn) and Syzygium aromaticum (L.). The study was conducted at an ambient temperature (28 ± 3ºC) and relative humidity (75 ± 6). Bruchids were exposed to dosages ranging from 0.05 to 0.55 g/20 g cowpea. The morphometrics of the cowpea seeds and emerged bruchids were also subjectively determined. GBV generally had significantly longer, wider, and thicker seeds than SKV. Similarly, GBV-reared bruchids were significantly (P 0.001) wider and longer in body size than SKV-reared bruchids. Regardless of cowpea variety, S. aromaticum was generally more toxic to the bruchids than P. guineense. GBV-reared bruchids were more susceptible to both plant powders than SKV-reared bruchids. The specific activities of Superoxide Dismutase, Catalase, and Glutathione also varied with cowpea varieties and plant powders. Cowpea variety, experimental dosage, and their interaction (V*D) significantly (P 0.001) influenced the specific activities of the three enzymes. Hence, the two plant powders, especially S. aromaticum, could be used as effective protectants of cowpea seeds against C. maculatus infestation. The findings in this study could ultimately contribute to ensuring the security and integrity of cowpea seeds, sustaining them as a staple food crop.

Metabolic alterations in cowpea submitted to water stress

Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency is one of the main environmental limitations that influence agricultural production in the world. The objective was to evaluate changes in carbon and nitrogen metabolism in cowpea plants exposed to water deficit. The experiment was conducted in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 x 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. Changes in the metabolism of cowpea plants were evident, with alterations in the activity of the nitrate reductase enzyme, concentrations of total soluble proteins, soluble amino acids, free ammonium and nitrate in the leaf tissue and roots.

Mineral composition and chlorophyll fluorescence in cowpea plants amended with bulk and nanoparticles of Zn and Cu oxides

Zinc oxide (ZnO-NP) and copper (CuO-NP) nanoparticles have been proposed for crop fertilization, but studies demonstrating their efficiencies and evaluating their phytotoxicities compared to bulk sources are still scarce. Here, we assessed the dissolution of Zn and Cu oxides of nanoparticulate and bulk sources and their effects on cowpea’s biomass, nutritional status, and photosynthetic apparatus. The results showed that Zn and Cu dissolution rate and release from nanoparticulate oxides were higher than bulk oxides. Regardless of the source, the addition of Zn and Cu concentrations to the solution increased the root, stem, and leaf tissue concentrations of these micronutrients and reduced the contents of nutrients and pigments, with consequent inhibition of photosynthesis as indicated by the parameters of chlorophyll fluorescence. Except for the lowest rate of the sources tested, biomass was reduced due to metal toxicity. However, biomass decreasing was not related to the source itself but to the nanoparticle source higher solubility, which promoted higher phytotoxicity.

Evaluation of Methods of Adding Chitosan and Potassium Silicate on Some Soil Fertility and Cowpea (Vigna ungiculata) Plant Productivity

This work aims to evaluate two methods of chitosan and potassium silicate application in 10, 15, and 20 days water irrigation on soil fertility and cowpea (Vigna unguiculata) productivit. A field experiment was conducted in saline soil located in Sahl El-Hossinia at El-Sharkia Governorate. The location lies between latitude 32° / 00 to 32° / 15, N and longitude 30° / 50 to 31° / 15 E. For two successive summer seasons 2021 and 2022 cultivated with Cowpea, to study the evaluation of two methods applied for chitosan and silicate potassium combined with or without mineral N fertilizers different rate on some soil fertility and cowpea productivity under irrigation water periods. The experiments were carried out in a split-plotdesign with three replicates. Results obtained that the decreases of soil pH and soil salinity, as well as the increase of available macro-micronutrients contents in soil as affected with potassium silicate foliar application combined with mineral N through intervals irrigation period 10 days compared to other treatments. the increase of plant height (cm), No. of pods/plant, No. of branches /plant, weight 100 seeds (g), weight pods (ton/fed), and seeds yield (ton/fed) with increasing mineral N fertilizer rate combined with potassium silicate foliar application under irrigation water interval 10 days compared with other treatments. Also, the highest mean values of N, P, Fe, Mn, and Zn concentrationsin seeds cowpea 4.16, 0.67, 9.20, 40.22 and 24.64 % respectively as affected with potassium silicate foliar application under irrigation water interval of 10 days than other treatments. From the previous results, we found that the method of foliar application of potassium silicate and chitosan under irrigation water at different periods has significant effects on all soil and plant characteristics compared to the soaking method.

Osmotic regulators in cowpea beans plants under water deficiency.

Cowpea is a leguminous plant belonging to the fabaceae family cultivated in the North and Northeast regions of Brazil, with productive potential. Among the abiotic factors, water deficiency is one of the main environmental limitations that influence agricultural production in the world. The objective of this work was to study the relative water content and osmoregulators of cowpea plants subjected to water stress. The experiment was carried out in a greenhouse at the Universidade Federal Rural da Amazônia (UFRA, Belém, PA), cowpea plants BR-17 Gurguéia Vigna unguiculata (L.) Walp were used. The experimental design was completely randomized (DIC) in a 2 × 2 factorial scheme, two water conditions (control and water deficit) and two times of stress (four and six days of water suspension), with 7 replications, totaling 28 experimental units. The water deficit affected plants, causing a reduction in relative water content (69.98%), starch (12.84% in leaves and 23.48% in roots) and carbohydrates (84.34%), and an increase in glycine-betaine, sucrose (114.11% in leaves and 18.71% in roots) and proline (358.86%) at time 2. The relative water content was negatively affected by water conditions, with a decrease in relation to the interaction of the aerial part and the root system. Therefore, greater metabolic responses were noted in plants that were subjected to stress treatment at time 2 (6 days).

Mass multiplication of native rhizospheric bacteria on cheaply available organic substrates and their plant growth promotion potentiality on cowpea

The intensive agricultural system results into considerable environmental damage and its inevitable effects on various environmental and ecological factors. Known for their role in the natural disease-suppressiveness of particular soil, Fluorescent pseudomonads are a genus of root-associated bacteria that may colonise the roots of agricultural plants and create antifungal metabolites, making them a viable alternative to the use of chemical fungicides. The successful application of Fluorescent pseudomonads as bioinoculants depends to a great extent on their capability to establish roots and to contend with indigenous microbiome in the rhizosphere. Because of various limitations, variations in the bio control agents are bound to occur in different agro-climatic regions, so it is advisable to choose native bio control agents. In the present investigation, a comprehensive effort was undertaken to check the growth of Pseudomonas aeruginosa (GP-8), which was found to be much lesser in aqueous extracts of cow dung, vermicompost and groundnut cake as compared to the growth of GP-8 (Pseudomonas aeruginosa) in nutrient broth media. The enrichment of Nitrogen and other supplementary nutrients may be required for the development of low cost indigenous media from cheaply available substrates for commercial mass production of Pseudomonas aeruginosa (GP-8) and also a field level screening trial was undertaken with efficient native Fluorescent pseudomonads solely or in consortia for improvement of plant health and management of soil borne pathogens as well as to develop a culture media with cheap and readily available substrate sources for mass production of Fluorescent pseudomonads strains. In the present study, it was found that shoot length and root length of native Fluorescent pseudomonads inoculated cowpea plants were significantly increased as compared with those of the control plants both at 30 and 60 days after sowing.

Impact of Sowing Date and Integrated Control of Etiella zinckenlla Treitschke (Lepidoptera) Infected Cowpea Plants

Impact of Sowing Date and Integrated Control of Etiella zinckenlla Treitschke (Lepidoptera) Infected Cowpea Plants

RESEARCH ON THE CONTROL OF DISEASES AND PESTS IN COWPEA CULTURE IN THE CONDITIONS OF SANDY SOILS IN THE SOUTH OF OLTENIA

The study was carried out in the period 2021-2022 at the Research and Development Station for Plant Culture on Sands Dabuleni, Romania, with the aim of finding scientific solutions to reduce the incidence of attack produced by the identified harmful agents in the cowpea crop (Vigna unguiculata L. Walp) sown in the conditions of the sandy soils of southern Oltenia, Romania. Various environmentally friendly products with a fungicidal and insecticidal role were tested, in order to promote sustainable agriculture, by applying two phytosanitary treatments in the phases of 3-4 true leaves and the appearance of flower stalks of the cowpea plant. The results obtained for cowpea highlighted the phytosanitary treatment with the Polyversumbiofungicide, in a dose of 0.1 kg/ha and the Bioinsekt insecticide, in doses of 0.5-1 l/ha, which achieved the best phytosanitary control over the attack produced by plant pests (AD=0.79%), correlated with an increase in resistance to stress conditions (bound water=3.42%; vacuolar juice concentration=10.2%) and high productivity (12.6 pods/plant, leaf index=8.04, production=2725.2 kg/ha).

Halotolerant Bacillus Species as Plant Growth Promoting Rhizobacteria from Hyper – Arid Area of Algeria

The aim of this study was to determine the diversity of aerobic halophilic and halotolerant Bacillus (AHHB) Plant Growth Promoting Rhizobacteria (PGPR), producing hydrolytic exo-enzymes and their inoculation effect in on two cowpea plants. Therefore, soil dilution plate technique was performed on Tryptic Soy Agar complemented with a thermal pretreatment to select Bacillus strains associated to Phoenix dactylifera rhizosphere growing in hypersaline and arid soil of Algeria (In Salah, Tamanrasset). The inoculation effect of these strains on cowpea plants growth was assessed based on biometric and physiological parameters. As results, thirteen halophilic, halotolerant and non-halophilic Bacillus strains were isolated. Upon screening, all strains are capable of producing at least two hydrolytic enzymes under saline conditions and most of the strains (n=10/13) showed at least two PGP traits. Strains were identified based on their phenotypic and biochemical characteristics as members of Bacillus genera. The inoculation of these strains in cowpeas had significantly improve biometrics and physiological growth parameters of inoculated plant. Based on general plant aspect, four strains are distinguished: RP 7 (B. coagulans), RP 8 (B. circulans), RP 10 (Paenibacillus polymyxa) and RP 12 (B. circulans). The isolation and characterization of halophilic and halotolerant Bacillus strains has increased knowledge of the rhizocompetent bacterial community associated with date palm in saline and arid soils. AHHB have proven to be highly effective strains to improve cowpea plant growth and development.

Soil properties the physiological and biochemical impact of bio-stimulants on cowpea plants against water deficit.

Soil properties the physiological and biochemical impact of bio-stimulants on cowpea plants against water deficit.

Chemical composition of the headspace volatiles of intact cowpea pods and cowpea pods infested by Riptortus dentipes and Nezara viridula pests

Volatile organic compounds are released by plants in defense against herbivory feeding by insect pests. Pod-sucking bugs can cause 30–70 % yield losses in cowpea (Vigna unguiculata) which serves as a major source of rich proteins and vitamins for humans and animals, as well as a source of income for farmers. The purpose of this study was to determine the chemical composition of the headspace volatiles of intact cowpea pods (Vigna unguiculata) variety (Padituya), and when it is infested by two pod-sucking bugs Riptortus dentipes and Nezara viridula. Headspace volatile collection was employed to collect volatile organic compounds from the intact cowpea pods, cowpea pods infested with Riptortus dentipes, and cowpea pods infested with Nezara viridula. Entrainment was done for 96 h in each case. The entrained volatiles were analyzed by gas chromatograph coupled with a mass spectrometer (GC-MS). Analysis of GC-MS data led to the identification of 1-octen-3-ol, 3-octanol, 2-nonanone, oleic acid, octadecanoic acid and dodecanoic acid as the volatiles released by the cowpea pod without insect attack. Cowpea pods attacked by Riptortus dentipes released hexanoic acid, 3-hexenoic acid (E), hexanoic acid, 2-hexenyl hexanoate (E), 2-tridecanone, 1-(4-ethylphenyl)-ethanone and eicosanoic acid. Upon infestation with Nezara viridula, the pods released 2-pentanone, 4-hydroxy-4-methyl-, 3-ethylbenzaldehyde, 1-(4-ethylphenyl)-ethanone and 2-decenyl acetate (E). With the exception of 1-(4-ethylphenyl)-ethanone, different volatile organic compounds were released by the cowpea plant against the two pests upon infestation. These compounds could be synthesized and used in integrated pest management of these pests to reduce losses in yield of cowpea production.

Novel Bioformulations with Trichoderma lixii to Improve the Growth Dynamics and Biocontrol of the Cowpea Damping-Off Disease

Because agricultural wastes are abundant in biologically active substances, they can be used as a substitute source to produce highly valuable products while lowering pollution levels in the environment. Therefore, we aimed at determining the best agricultural wastes to increase the biomass production rate and the effectiveness of the biocontrol strain Trichoderma lixii SARS 111 in a solid-state fermentation system. The potential for its use in enhancing growth dynamics and controlling the Fusarium oxysporum NCAIM-F-00779-caused damping-off disease of cowpea plants grown in greenhouse conditions was also studied. Using a one-factor-at-a-time experiment, five cheap agricultural waste substrates (faba bean, cowpea, sweet potato, pumpkin, and cassava) were studied using the Plackett–Burman design (PBD) and the central composite design (CCD) to optimize the nutritional and growth conditions to maximize the production of Trichoderma conidia. The findings demonstrated that increasing Candida production quantitatively required the use of 3 g of sweet potato, 3 g of cassava, pH 6, 25 °C, and pre-treatment with dH2O. The shelf life and viability of T. lixii strain were measured as log10 CFU g−1 per substrate at room temperature (RT, 25 °C) at the beginning of month 0 and subsequently at 2-month intervals for 12 months. Data showed that the fungal counts increased with the use of 4 g of sweet potato + 2 g of cassava up to 7 months and then sharply decreased, lasting up to 12 months. Additionally, this bioformulation was applied to cowpea plants in a greenhouse experiment, where a significantly higher level of plant growth traits, photosynthetic pigments, antioxidant enzymes, and chemical content in the leaves, as well as lower incidence of the damping-off disease, were noted. Accordingly, it is possible to suggest 4 g of sweet potato and 2 g of cassava as a suitable bioformulation for the industrial-scale production of the T. lixii strain, which may be a potential biocontrol agent for preventing the cowpea damping-off disease caused by F. oxysporum and improving the growth dynamics.

Evaluation of Biofertilizers Prepared from Local Bacterial Isolates in the Growth and Yield of Cowpea in Gypsiferous Soil

For clean and sustainable agriculture based on natural, non-chemical products, a field experiment was conducted during the agricultural season 2021-2022 on the cowpea plant in Salah Al-Din Governorate to evaluate the effect of six biofertilizers prepared from local bacterial isolates, which included: Bradyrhizobium manausense, Bradyrhizobium vignae, Rhizobium sp., Enterobacter cloaca, Enterobacter ludwigii, Bacillus cereus, in the growth and yield of cowpea in gypsiferous soil. The results showed that all inoculated treatments were significantly superior to the control treatment in all growth and yield traits of cowpea plant, it also appeared that a significant superiority of Brad. manausense biofertilizer followed by Brady. vignae in all plant traits: root nodules number, weight of root nodules, plant height, dry weight of plant, early yield of pods, concentration of nitrogen and phosphorus in plant as it recorded 53 nodule plant−1, 2.01 g nodule−1, 58.42 cm, 63.83g plant−1, 3658 g plant−1, 4.12 N %, 0.49 P % respectively, compared to the control treatment which recorded 0 nodule plant−1, 0 g nodule−1, 27.1 cm, 15.32g plant−1 950 g plant−1, 1.34 N %, 0.13 P % respectively, and the results showed that the treatments with Rhizobium sp., Enterobacter cloaca, Enterobacter ludwigii, Bacillus cereus biofertizers did not record any formation of root nodules, also the results indicated that the treatment inoculated with the inoculum prepared from Enterobacter cloaca bacteria was superior to Rhizobium sp, Bacillus cereus, Enterobacter ludwigii treatments in plant height, shoot dry weight and pod yield of cowpea plant.

Evaluation of Inoculation with Bradyrhizobium manausense and Bradyrhizobium venae on the Elemental content of Cowpea Plant in Gypsum Soil

A field experiment was conducted during the spring season on 3/25/2022 in the fields of the University of Tikrit / College of Agriculture located in the research station of the Department of Soil Sciences and Water Resources, with the aim of studying the effect of inoculation with Rhizobia bacteria and nitrogen fertilization on the growth and yield of cowpea in gypsum soil, conducted in a randomized complete block design. R. C. B. D With three replications, the experiment included two main factors: inoculation with rhizobium bacteria, and the second factor was nitrogen fertilization. The inoculation factor was three levels (A0 = no inoculation, A1 = inoculation with the first strain, Bradyrhizobium manausense, and A2 = inoculation with the second strain, Bradyrhizobium vignae), and the second factor was nitrogen fertilization. At three levels N0 and N1 = 40 kg / ha and N2 = 80 kg / ha, the process of isolation and development of Rhizobium bacteria was conducted on the optional medium (YEMA), and the two isolates were identified and recorded in the National Center for Biotechnology Information (NCBI) by number Global OP740389 Bradyrhizobium vignae, as for the results of the field experiment, the inoculation treatment with root nodes bacteria Bradyrhizobium vignae was superior to the control treatment and even to the second strain Bradyrhizobium manausense in all studied traits of cowpea plant, and the percentage increase of the inoculation treatment with Bradyrhizobium vignae with 40 kg of nitrogen fertilizer was higher than The control treatment in the number of root nodes and their wet weight (1474.87, 267.101)%, respectively, and the concentration of nitrogen, phosphorus and potassium in the vegetative part (61.300, 1.600, 7.102)%, respectively.

Evaluation of Inoculation with Two Strains of Rhizobium Bacteria on some Growth and Yield Traits of Cowpea Plant in Gypsiferous Soil

A field experiment was conducted during the spring season on 3/25/2022 in the fields of Tikrit University / College of Agriculture located in the research station of the Department of Soil Sciences and Water Resources, with the aim of studying the effect of inoculation with Rhizobia bacteria and nitrogen fertilization on the growth and yield of cowpea in gypsiferous soil. It was conducted with a completely random block design R. C. B. D With three replicates, the experiment included two main factors: inoculation with rhizobium bacteria, and the second factor was nitrogen fertilization. The inoculation factor was three levels (A0 = non inoculation, A1 = inoculation with the first strain, Bradyrhizobium manausense, and A2 = inoculation with the second strain, Bradyrhizobium vignae), and the second factor was nitrogen fertilization. With three levels N0 and N1 = 40 kg / ha and N2 = 80 kg / ha, the results showed the excelled of the inoculation treatment with root nodules Bradyrhizobium vignae on the control treatment and even the second strain Bradyrhizobium manausense in all studied traits of cowpea plant, and the percentage increase of the inoculation treatment was Bradyrhizobium vignae with 40 kg nitrogen fertilizer over the comparison treatment in the number of root nodes and their wet weight (1474.87, 267.101)%, while the dry weight of the root and vegetative total, plant length and roots, the increase was (44.347, 79.283, 12.771, 21.233)%, respectively, and the number of pods of the early yield And the total (120.925, 4.303)%, and the plant yield of straw (46.054), respectively.