Growth Of Cowpea Plants Research Articles

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.

Effects of biochar, zeolite and mycorrhiza inoculation on soil properties, heavy metal availability and cowpea growth in a multi-contaminated soil

Heavy metal pollution of agricultural soil has become a major serious concern. The development of suitable control and remediation strategies for heavy metal contaminated soil has become critical. The outdoor pot experiment was conducted to investigate the effect of biochar, zeolite, and mycorrhiza on the bioavailability reduction of heavy metals and its subsequent effects on soil properties and bioaccumulation in plants as well as the growth of cowpea grown in highly polluted soil. Zeolite, biochar, mycorrhiza, zeolite with mycorrhiza, biochar with mycorrhiza, and soil without any modifications were the six treatments used. The experiment was conducted with a completely randomized design and four replications. The results indicated that the combination of biochar with mycorrhiza had the highest values of root and shoot dry weight and the lowest heavy metal concentrations in root and shoot as well as bioconcentration and translocation factors for all heavy metals. The highest significant reductions in the availability of heavy metals over the control were found with biochar with mycorrhiza, which were 59.1%, 44.3%, 38.0%, 69.7%, 77.8%, 77.2% and 73.6% for Cd, Co, Cr, Cu, Ni, Pb and Zn, respectively. The application of biochar and zeolite either alone or in combination with mycorrhiza increased significantly soil pH and EC compared to mycorrhiza treatment and untreated soil. It can be concluded that the combination of biochar and mycorrhizal inoculation has great potential as a cost-effective and environmentally technique for enhancing heavy metal immobilization, lowering heavy metal availability and plant uptake, and improving cowpea plant growth.

Isolation and Characterization of Stress-Tolerant Priestia Species from Cowpea Rhizosphere Under Drought and Nutrient Deficit Conditions

This study aimed to isolate stress-tolerant phytobeneficial bacteria as bio-inoculants for cowpea's sustainable growth under drought and nutrient deficiency conditions. However, the application successful of phytobeneficial bacteria is subject to effective in vitro screening under different physiological conditions. We isolated several Priestia species from cowpea rhizosphere that tolerates polyethylene glycol (PEG6000)-induced drought and nutrient deficiency. Of them, C8 (Priestia filamentosa; basonym: Bacillus filamentosus), followed by C29 (Priestia aryabhattai; basonym: Bacillus aryabhattai), tolerated up to 20% PEG in a low-nutrient medium. In the presence of PEG, Priestia filamentosa and Bacillus aryabhattai exhibited optimal growth in different temperatures and pH but failed to survive at extreme temperatures of 45°C and pH 11. Priestia filamentosa preferred L-proline and L-glutamate, while L-tryptophan and L-tyrosine were the least utilized. Interestingly, Priestia filamentosa and Bacillus aryabhattai used more complex nitrogen sources, peptone, and yeast extract, than inorganic nitrogen for growth. Most importantly, under drought and nutrient deficiency, Priestia filamentosa exhibited multiple plant growth-promoting traits and more amylase and protease production than C29. Our results indicate that Priestia filamentosa is a potential bacterium to enhance the growth of cowpea plants under stressful conditions.

Correction to: Effect of Doping on TiO2 Nanoparticles Characteristics: Studying of Fertilizing Effect on Cowpea Plant Growth and Yield

Correction to: Effect of Doping on TiO2 Nanoparticles Characteristics: Studying of Fertilizing Effect on Cowpea Plant Growth and Yield

Effect of Doping on TiO2 Nanoparticles Characteristics: Studying of Fertilizing Effect on Cowpea Plant Growth and Yield

Effect of Doping on TiO2 Nanoparticles Characteristics: Studying of Fertilizing Effect on Cowpea Plant Growth and Yield

Alleviation of Natural Salinity Stress on Seedlings and Growth of Cowpea Plants Using Some Different Protective Treatments تفادي تأثير الإجهاد الملحي الطبيعي علي إنبات ونمو نباتات اللوبيا باستخدام بعض المعالجات المختلفة

The current research was conducted to alleviate natural salinity stress on seed germination by seed priming and within turn on vegetative development using some different treatments. In laboratory, Seeds were soaked in chitosan (0.2 g/L), potassium silicate (1.1 g/L), and yeast extract (20 g/L) compared to control treatment for 3½ hours under different salinity stress (0, 5 and 7 dS/m)for 3½ with. Previous seeds were planted under the same levels of natural saline stress in two fields of the Agricultural Research Center in Damietta governorate, during 2018-2019 seasons. Two types of treatments were used, sulfur (0.4 ton/fed.) and sulfuric acid (10 L/ fed.) as soil amendments and the same previous soaking compounds used to seed priming as foliar application treatments. Results reveal that elevated the salinity stress had a negative feedback on cowpea seedlings and growth traits. Meanwhile, each of chosen protective treatments had significantly improvement of seed priming and vegetative growth traits. The major improved interaction for the formerly characteristics was the combined addition of sulphur in soil with spraying chitosan or with yeast extract under natural salinity stress. Therefore, we recommend adding sulfur to the soil (0.4 ton/fed.) before cultivation and soaking the seeds of cowpea (Kaha 1) to prepare it for germination (Seed priming) as well as spraying plants by chitosan (0.2 g/l) or spraying with yeast extract (20 g/l) after 20 days after sowing, three times, ten days intervals, to increase plant tolerance to natural soil salinity for obtain the best vegetable growth under the same conditions.

Effect of Microwave Radiation on Bacteria, Fungi and Some Growth Characteristics of Cowpea Vigna unguiculata L.

In this study, an experiment was conducted to describe the effects of using microwaves and chemical fertilization (isolated and combined) on the number of bacteria and fungi in the soil and on the growth of cowpea plants Vigna unguiculata L. Several times of exposure to microwave radiation (0, 25, 30, 35, 40, 45 s) and several concentrations of chemical fertilizer NPK (0, 0.9, 1.8 g 3 kg−1 soil) were carried out. After individual and combined treatments, experiments were carried out to quantify microorganisms (bacteria and fungi). In addition, 45 days after planting, analyzes were made of the cowpea plants for their development under different experimental conditions. The experiment was conducted in plastic pots to find out some characteristics of plant growth. The results indicated that the microwave sterilization resulted in the complete killing of bacteria and fungi and the fertilizer additive (NPK) to the soil had a critical role in increasing the values significantly for the number of root nodes and the remaining plant growth characteristics measured in this study.

Evaluation of Growth and Morphological Pattern of Mycorrhization in Cowpea [Vigna unguiculata (L.)] Fertilized With Phosphorus

Microorganisms perform important functions in the soil and, among these organisms, the role of arbuscular mycorrhizal fungi (AMF) in plant growth should be highlighted. AMF colonize the roots of most plant species and their beneficial functions in plant development include increased absorption of nutrients from the soil, especially those of low mobility such as phosphorus (P). Evaluating agricultural practices conducted by farmers, such as phosphate fertilization, and observing how they will influence AMF activity in benefiting plant growth should be prioritized. Thus, an experiment was conducted in greenhouse to evaluate the effect of phosphate fertilization on the growth of cowpea plants colonized by AMF and to know which morphological pattern of colonization prevails in their roots. Five P doses and a control treatment, without fertilization, were added to the soil. Cowpea plants respond to phosphate fertilization up to the dose of 240.50 mg P kg-1 soil, for shoot dry mass and in the dose of 150 mg P kg-1 soil, for plant height. The morphological pattern observed in the roots was the intermediate type, characterized by the presence of intra and intercellular hyphae and vesicles, and there was no influence of phosphate fertilization on morphology. High P contents added to the soil led to a reduction in mycorrhizal colonization in cowpea roots.

Bioaccumulation of Transition Metal Oxide Nanoparticles and Their Influence on Early Growth Stages of Vigna unguiculata Seeds

A reasonable understanding of the impact and health risk of the metal oxide nanoparticles treated on edible plants is necessary in order to use nanomaterials in food and medicine. In this study, we investigate the uptake and toxic response of transition metal oxides, namely Fe2O3, CuO and ZnO nanoparticles synthesised by co-precipitation method using nitrate salts of the respective metals as precursors. The characterisation of all the prepared nanoparticles shows the purity above 97% with rod-like morphology. Cowpea (Vigna unguiculata) seeds are soaked in a monodispersed solution of nanoparticles and kept for seed germination and plant growth. Transport and accumulation of the nanoparticles treated in the seeds are assessed through X-ray fluorescence spectroscopy which confirms the uptake of the nanoparticles with respect to the treatment regime. The seeds soaked in CuO nanoparticles reveal better seed germination percentage, an increased coleoptile length and a plant height at 100 ppm concentration than other nanoparticles. This study proves the limitation of CuO nanoparticle application for better growth of cowpea plants whereas iron and zinc oxide nanoparticles show promising response in plant growth, uptake and bioavailability in seeds even at higher treatments.

Competition between cowpea and weeds for water: Effect on plants growth

Water is the most important resource for agricultural production. The understanding of water competition mechanisms may lead to the development of new control strategies or coexistence with certain weed species, especially in situations where water is scarce. The objective of this work was to evaluate the competition between cowpea and weeds by water under the effect on plant growth. It was carried out experiment in greenhouse in the period from September to November 2015, in a randomized complete block design, with four replications. The treatments were arranged in factorial 5 x 2, with the first factor corresponding to the competition arrangements between the species (V. unguiculata + C. benghalensis; V. unguiculata + W. indica; V. unguiculata, C. benghalensis and W. indica in monoculture), and the second of water regimes (irrigated and water deficit). The water deficit reduces the growth of cowpea plants, C. benghalensis and W. indica. The competition between plants increases the effects of temporary water deficit in the soil. The W. indica leaf is the organ most affected by the water deficit. The weed specie W. indica has greater capacity competition for water with V. unguiculata than C. benghalensis.

Integrated Effect of Foliar Fertilization of Fe, Zn and Rates of P Fertilization on Growth and Yield of Cowpea

At the Experimental Farm of Faculty of Agriculture, El-Mansoura University, Egypt, a field experiment was carried out, to investigate the effect of zinc and iron individually or mixed as foliar application on cowpea plant growth, chemical composition, yield and its components as well as availability of nutrients in the soil, all that under phosphorus application effect. The experiment was laid out in split plot design with three replicates, assigning twelve treatments consisting of three levels of phosphorus (50, 100 and 150% from recommended dose) as main plot, and four levels of micronutrients foliarly (without, Zn, Fe and Zn+Fe) as sub plot. As for the effect of P-fertilization, the results show that all treatments significantly increased vegetative growth (plant height (cm), no. of branches/plant, no. of leaves/plant), yield and its components (No. of pods/plant, No. of seed/pod, 100 seed weight g and Seed yield Kg/fed.) as well as chemical (N, P, K, Zn and Fe) and quality composition (chlorophyll content, c.protien, T. carbohydraties and C. fiber.). These effects were more obvious especially at higher concentrations of these treatments 150% RD except chlorophyll content, quality parameters with 100% RD. The highest mean values of available P, Zn and Fe in the soil were recorded for the plants treated with P-fertilization at the rate of 100% from recommended dose, whereas the lowest values of available N and K were realized for the same treatment. On the other hand, foliar application with micronutrient has a significant effect on cowpea growth. The highest values of parameters observed with the mix of (Zn+Fe) comparing with the untreated plant. Moreover, the mix of micronutrient (Zn+Fe) recorded the highest values of available P, Zn and Fe, whereas the highest values of available N and K were recorder with the untreated plant. The interaction effect between P fertilization and micro nutrients show a promotive effect on growth parameters with using mix of Zn+Fe. The highest mean values of parameters was recorded under 150% P from RD, whereas the highest mean values of chlorophyll content, quality parameters and available P, Zn and Fe recorded with 100% P from RD and the lowest values of available N and K were realized for the same treatment.

A SNP-based association analysis for plant growth habit in worldwide cowpea (Vigna unguiculata (L.) Walp) Germplasm

Cowpea is a legume widely grown in Africa, North, Central and South America, and Asia. The cowpea plant growth habits consist of erect, semi-prostrate, and prostrate types. Developing a cultivar while considering plant growth habit is essential within a breeding program since the need for a particular growth habit is region-specific, and significantly depends on the end user preference. Some cowpea growers might prefer erect types over semi-prostrate and prostrate types, while others would chose prostrate types, which provide more leaves for feed supplies to livestock. However, very little is known regarding the genetics of plant growth habit in cowpea to assist plant breeders in developing suitable cowpea cultivars having the desired growth habit plus the other required features. Therefore, the objectives of this study were to conduct an association mapping for cowpea growth habit, and to identify SNP markers associated with this trait. A total of 487 cowpea genotypes were evaluated for growth habit and a total of 1031 SNPs postulated from genotyping-by-sequencing to conduct association analysis study for cowpea growth habit. Our results showed that: (1) significant differences in cowpea growth habit were identified between countries, (2) the cowpea erect-type was prevalent, and (3) ten SNP markers, C35060651_729, C35061339_799, C35062457_1855, C35072764_1384, C35080248_2355, Scaffold2771_4351, Scaffold29522_3213, Scaffold35913_2678, Scaffold53560_188, and Scaffold58098_4297, were significantly associated with cowpea growth habit. These results could be used for enhancing marker-assisted selection (MAS) in breeding programs aimed at developing cowpea cultivars having a particular growth habit.

Response of water deficit-stressed Vigna unguiculata performances to silicon, proline or methionine foliar application

Abstract Environmental stresses are increasing over time adversely affecting crop productivity. To face these stresses, plants adopt endogenous mechanisms, but they are not enough in most cases. Therefore, the effect of exogenous application of proline, silicon (Si) or methionine on growth and yield criteria, leaf physio-biochemical properties and leaf anatomical structure of cowpea plants grown under three levels of water deficit (W0; 60, W1; 40 and W2; 20% of soil water holding capacity) was investigated. The water level W0 was adequate to optimum cowpea plant growth and specified as a control. Results obtained indicated that growth criteria (i.e., shoot dry weight, plant height, leaf area and number of branches per plant), yield characteristics (i.e., dry seed weight and biological yield per plant, and 100-seed weight), contents of leaf chlorophylls a and b, total carotenoids, shoot and seed nutrients (i.e., N, P and K), and leaf relative water content and membrane stability index were significantly decreased, while activity of leaf antioxidant enzymes such as peroxidase (POX), superoxide dismutase (SOD) and catalase (CAT), content of leaf proline and electrolyte leakage, and shoot Si were significantly increased under water deficit stress (W1 and W2) conditions compared to the control (W0). However under water deficit stress, foliar application of proline, Si or methionine seemed to overcome the harmful effects of water deficit stress, at varying degrees, on the abovementioned cowpea plants characters, which were improved, compared to the corresponding controls. The Si was the most helpful one, where it increased growth criteria (i.e., shoot dry weight, plant height, leaf area and number of branches per plant), yield characteristics (i.e., dry seed weight and biological yield per plant, and 100-seed weight), contents of leaf chlorophylls a and b, total carotenoids, shoot and seed nutrients (i.e., N, P and K), and leaf relative water content and membrane stability index, and further increased shoot Si content and leaf antioxidant enzyme activities of cowpea plants compared to those of either proline or methionine application. For leaf anatomical features, the width of midvein and xylem, and the thickness of midvein, phloem and xylem tissues, and palisade and spongy tissues of leaf blade were decreased with increasing the water deficit stress; however, foliar spray of Si improved all histological features compared to those of untreated plants.

Amelioration of salinity tolerance in cowpea plants by seed treatment with methyl jasmonate

A pot experiment was conducted to investigate the role of methyl jasmonate (MeJA) in alleviation of the adverse effects of salinity on cowpea. Seeds were soaked in 0, 25 and 50 µM MeJA for 20 h and then the seedlings were irrigated with different concentrations of NaCl (0, 50 and 100 mM). Salt stress markedly decreased growth attributes namely shoot length, shoot and root dry weight and leaf area. NaCl stress also significantly reduced chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins and relative water content (RWC). Furthermore, salinity noticeably increased proline and total soluble sugars content. Nonetheless, seeds treatment with MeJA especially 50 µM, improved the growth of cowpea plants by increasing chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins, proline accumulation, total soluble sugars and RWC under salt stress conditions. Thus results indicate that pretreatment of seeds with MeJA could be used as an effective technique for improving cowpea plants tolerance to salt stress.

Initial development of cowpea plants under salt stress and phosphate fertilization

The objective of this work was to study the effects of irrigation with saline water associated with phosphate fertilization on the emergence and early growth of cowpea plants. The assay was conducted in the greenhouse of the Department of Environmental Sciences and Technology of the Federal Rural University of the Semi-Arid (UFERSA) in Mossoró-RN, during October and November of 2015. The study adopted a randomized block with treatments arranged in a 5 x 3 grid, corresponding to five levels of water salinity (0.5, 1.5, 2.5, 3.5 and 4.5 dS m-1) and three doses of superphosphate, based upon the soil analysis (60%, 100% and 140% of the recommended dose for the crop 60 kg P2O5 ha-1), with five repetitions. The cowpea plants, cv. Paulistinha, were grown in lysimeters with capacity of 8 dm3. During the first 15 days of the initial stage of development the plants were evaluated for emergence, growth and biomass accumulation. The increase in water salinity above 1.5 dSm-1 reduced the emergence, growth and dry matter accumulation of cowpea plants. The increase of 40% in the recommendation of phosphorus fertilization of cowpea increased the growth and biomass accumulation of shoot plants, regardless of salinity.

Accumulation of salts in the soil and growth of cowpea under salinity and phosphorus fertilization

Cowpea is widely grown in the Brazilian semiarid region, however, due to excess salts in the soil and irrigation water constantly low crop productivity has been observed. Accumulation of salts in the soil, growth and biomass partition of cowpea under salt stress and phosphorus fertilization was evaluated in this study. The assay was conducted in a greenhouse in Mossoro, State of Rio Grande do Norte, Brazil, from September to December 2015, using a Alfissol Latosolic with low phosphorus content. The experiment was carried out in a randomized block design in a factorial 5 x 3 arrangement, consisting of five water salinity levels (0.5, 1.5, 2.5, 3.5 and 4.5 dS m-1) and three doses of superphosphate (60, 100 and 140% of the recommended dose for crop - 60 kg ha-1 of P2O5), with five repetitions. The plants of cowpea cv. Paulistinha were cultivated for 49 days after sowing in lysimeters with 8 dm3 capacity. During this period was determined the accumulation of salts in the soil, growth and biomass partition plants. Water with salinity higher than 1.5 dS m-1 increased soil salinity above the crop’s threshold of 4.9 dS m-1, 21 days after sowing. Increased salinity impaired growth and biomass partition of cowpea plants, with greater accumulation of dry matter in the leaves and stem in comparison to the root. Hinghest dose of superphosphate promoted greater growth of cowpea plants.

Brassinosteroids improve photosystem II efficiency, gas exchange, antioxidant enzymes and growth of cowpea plants exposed to water deficit.

Water deficit is considered the main abiotic stress that limits agricultural production worldwide. Brassinosteroids (BRs) are natural substances that play roles in plant tolerance against abiotic stresses, including water deficit. This research aims to determine whether BRs can mitigate the negative effects caused by water deficiency, revealing how BRs act and their possible contribution to increased tolerance of cowpea plants to water deficit. The experiment was a factorial design with the factors completely randomised, with two water conditions (control and water deficit) and three levels of brassinosteroids (0, 50 and 100nM 24-epibrassinolide; EBR is an active BRs). Plants sprayed with 100nM EBR under the water deficit presented significant increases in ΦPSII, qP and ETR compared with plants subjected to the water deficit without EBR. With respect to gas exchange, PN, E and gs exhibited significant reductions after water deficit, but application of 100nM EBR caused increases in these variables of 96, 24 and 33%, respectively, compared to the water deficit+0nM EBR treatment. To antioxidant enzymes, EBR resulted in increases in SOD, CAT, APX and POX, indicating that EBR acts on the antioxidant system, reducing cell damage. The water deficit caused significant reductions in Chl a, Chl b and total Chl, while plants sprayed with 100nM EBR showed significant increases of 26, 58 and 33% in Chl a, Chl b and total Chl, respectively. This study revealed that EBR improves photosystem II efficiency, inducing increases in ΦPSII, qP and ETR. This substance also mitigated the negative effects on gas exchange and growth induced by the water deficit. Increases in SOD, CAT, APX and POX of plants treated with EBR indicate that this steroid clearly increased the tolerance to the water deficit, reducing reactive oxygen species, cell damage, and maintaining the photosynthetic pigments. Additionally, 100nM EBR resulted in a better dose-response of cowpea plants exposed to the water deficit.

Inoculation with Native Bradyrhizobia Strains Improved Growth of Cowpea Plants Cultivated on a Saline Soil

ABSTRACTSelection of osmotolerant rhizobia gained importance because of increasing soil salinity in many regions. A field experiment in the Cauto Valley was conducted to determine the effect of seed inoculation with two native strains of Bradyrhizobium sp. on biological nitrogen (N)-fixation of cowpea (Vigna unguiculata) on a salt affected soil. Inoculation with both strains resulted in higher numbers of nodules, specific N-fixation, and yields of cowpeas than the control without inoculation. The strain VIBA-1 (Bradyrhizobium liaoningense) was partly superior to VIBA-2 (Bradyrhizobium yuanmingense). This study indicates that the strains inoculated are competitive against other natural strains and able to nodulate cowpea.

Efficiency of Trichoderma spp. as a growth promoter of cowpea (Vigna unguiculata) and analysis of phosphate solubilization and indole acetic acid synthesis

The aim of this study was to determine the efficiency of Trichoderma spp. in promoting the growth of cowpea plants. Strains were isolated from Tocantins savannah soils. Twenty-one isolates were evaluated in vitro for their ability to solubilize calcium phosphate and synthesize indole acetic acid (IAA). The soil samples were characterized physicochemically before planting. Eleven isolates were selected to evaluate the promotion of cowpea plant growth in the greenhouse in soil fertilized with phosphorite in 1.7-L pots. Then, at 32 and 45 days after planting (DAP), we determined the plant height (PH), root length (RL), dry matter of the aerial part (DMAP), root dry matter, total dry matter (TDM), relative efficiency (RE), and phosphate utilization efficiency (P-UEF) of the cowpea plants. The Trichoderma isolates showed a greater ability to synthesize IAA and solubilize phosphate than the controls. The best isolates for solubilizing phosphate were UFT 63, UFT 79, UFT 85, and UFT 201. The isolates UFT 25, UFT 79, UFT 110, and UFT 201 were more efficient in synthesizing IAA using tryptophan. The Trichoderma isolates exhibited P-UEF, especially isolates UFT 57, UFT 201, and UFT 204, with values of 430, 282, and 359 %, respectively, compared to controls. Consequently, the isolate UFT 201 (T. asperelloides GJS 04-217) showed greater potential as a growth promoter for cowpea, with a 38 cm PH, 29 cm RL, 4.5 g DMAP, and 5.8 g TDM at 45 DAP and a 256 % phosphorus content and 269 % RE compared to the control without inoculation.

Impact of some Soil Amendments and Mycorrhiza on Cowpea Damping-Off Caused by Rhizoctonia solani

Addition of biochar to soil improves carbon sequestration, soil fertility and plant growth, especially when combined withorganic compounds such as compost. This greenhouse study was carried out to examine the effects of soil amendments with biochar, compost and mycorrhiza as biofertilizer alone or in combinations on cowpea plant growth parameters and on suppression of damping-off disease caused by Rhizoctonia solani. In vitro experiment showed that biochar has no direct efficacy on the tested fungus even at the higher tested concentrations. A synergistic effect was noticed when cowpeaplants were grown in soil amended with biochar in the presence of mycorrhiza. Also, results indicated that the tested soil amendments and mycorrhiza improved the growth parameters as well as macronutrient contents of cowpea.