Effect of Liquid Formulation of Rhizobium and Phoshpate Solubilizing Bacteria on Growth and Yield of Black Gram (Vigna mungo)

The current investigation entitled “Effect of Liquid Formulation of Rhizobium and Phosphate Solubilizing Bacteria on Growth and Yield of Black Gram (Vigna mungo.)” was carried out as a field experiment at research farm, Plant Pathology and Microbiology, PGI, MPKV, Rahuri. The soil sample were collected from root rhizospeheric soil of black gram. This study involved the isolation of Rhizobium and PSB from root nodules and rhizospheric soil. The four isolates of Rhizobium i.e RH-I, RH-II, RH-III and RH-IV and three isolates for Phosphorous solubilizing bacteria i.e PS-I, PS-II and PS-III were isolated by serial dilution and pour plate method using YEMA and Pikovaskya’s medium respectively. These isolates undertook laboratory testing to determine their efficacy. The nitrogen fixing Rhizobium isolate RH-II fixed the highest amount of nitrogen (14.7 mg of Nitrogen/g of sucrose) than the other isolates tested. Moreover, the phosphate solubilizing bacterial isolate PS-II recorded the highest P-solubilization index (5.66) than the other isolates tested. One isolate of each was chosen as i.e RH-II and PS-II for further studies. Based on biochemical and physiological characterization nitrogen fixing rhizobial isolates were identified as Rhizobium leguminosarum and phosphate solubilizing bacterial isolate identified as Pseudomonas spp. This isolate were used for further field experimental studies. The field study was undertaken with nine treatments and three replications with randomized block design. Among the different inoculation treatments, seed inoculation with efficient isolated strain of Rhizobium and PSB from black gram with 75 % RDF was found to be the most effective as it recorded the highest germination (95.60%), leaf area index(), plant height(), number of root nodules, number of pods dry matter production, nutrient uptake and seed yield of black gram. The treatment reference strain of MPKV liquid formulation Rhizobium and PSB with 75% RDF and another treatment 100% RDF application these two treatments are at par with highest treatment. The results from the present investigation it can be concluded that seed inoculation with liquid formulation of Rhizobium and PSB with 75% RDF was found the most beneficial for getting higher seed yield of Black gram with 25% saving of nitrogen and phosphorus dose of chemical nutrients to black gram.