Effect of Seed Treatment and Phosphorus Levels on Growth, Yield and Economics of Cowpea (Vigna unguiculata L.)

Crop production encounters challenges due to the dearth of nitrogen and phosphorus, while excessive use of chemical fertilizers causes environmental hazards. Use of Rhizobium and phosphate solubilizing hazards. The use of Rhizobium and phosphate solubilizing bacteria can be a sustainable strategy to overcome these problems.

The present investigation was conducted during Kharif season of 2022 at Chamelti Agriculture Farm, MS Swaminathan School of Agriculture, Shoolini University of Biotechnology and Management Sciences, Solan, Himachal Pradesh. The soil of the experimental site was sandy loam in texture, slightly alkaline in reaction with EC in safer range, medium in organic carbon, available nitrogen, potassium and high in available phosphorus. The field experiment was laid out in a factorial randomized block design comprising sixteen treatments with three replications. The experiment consists of four levels of bio-fertilizer i.e., (S0) Control, (S1) Rhizobium 10 ml kg-1 seed, (S2) PSB 10 ml kg-1 seed and (S3) Rhizobium + PSB both 10 ml kg-1 seed as first factor and four levels of phosphorus i.e., (P0) control, (P1) 20 kg ha-1, (P2) 40 kg ha-1 and (P3) 60 kg ha-1 as second factor. Recommended dose of nitrogen and potassium (20:20 kg ha-1) was applied through urea and MOP at the time of sowing. Himlobia-2 variety of cowpea was used for sowing. Other crop management practices were followed as per the recommendation of the area.

Results indicated that among the seed treatments, seed inoculation with (S3) Rhizobium + PSB both 10 ml kg-1 of seed recorded significant improvement in growth, yield and economics of cowpea, over single inoculation of Rhizobium and PSB which was statistically at par with (S1) Rhizobium over rest of the treatments. Application of 60 kg P ha-1 resulted significantly higher growth, yield and quality of cowpea and was on par with 40 kg ha-1. Economically, (S3) Rhizobium + PSB both 10 ml kg-1 of seed along with application of 0 kg P ha-1 resulted in higher gross returns, net returns and B:C ratio under Mid-hills of Himachal Pradesh.