Effect of Phosphorus, Sulphur and Gibberellic Acid on Growth, Root Nodules and Yield of Soybean [Glycine max (L.) Merrill]

An experiment was conducted during kharif season 2020 at Instructional Farm, College of Agriculture, Ummedganj, Kota. The experiment comprised twenty-four treatment combinations, having four levels of phosphorus viz., 0, 20, 40 and 60 kg ha-1, three levels of sulphur viz., 15, 30 and 45 kg ha-1 and foliar spray of gibberellic acid viz., no spray and spray of GA3 @ 75 ppm laid out in sub-sub split-plot design with three replications. Results showed that application of 60 kg P2O5 ha-1 had significant effect on plant height, dry matter accumulation plant-1, branches plant-1 at 30, 60 DAS and at harvest, root nodules plant-1 and their dry weight at 45 DAS while root nodules plant-1 and their dry weight at 45 DAS andseed yield (1956 kg ha-1) over application of 40, 20 kg P2O5 ha-1 and control. Significantly higher seed yield (1956 kg ha-1) was recorded under application of 60 kg P2O5 ha-1 over application of 20 kg P2O5 ha-1 and control. However, it was found at par with application of 40 kg P2O5 ha-1. Application of 45 kg sulphur ha-1 had significantly higher plant height (cm) at 60 DAS and at harvest, dry matter accumulation (g plant-1) at 30, 60 and at harvest stages, branches plant-1 at 30, 60 and at harvest stage, number of root nodules and their dry weight (g) and seed yield (1742 kg ha-1) which was found at par with application of 30 kg sulphur ha-1 over 15 kg sulphur ha-1. Application of gibberellic acid @ 75 ppm as foliar spray gave significantly higher plant height (cm) at 60 DAS and at harvest stage, dry matter accumulation (g plant-1) at 60 DAS and at harvest, branches plant-1 at 30, 60 DAS and harvestand seed yield (1770 kg/ha) over control.