Influence of Phosphorus Levels and Biofertilizers on Growth and Yield of Cluster Bean (Cyamopsis tetragonoloba L.) under Semi-arid Conditions of Rajasthan, India

Abstract

Cluster bean [Cyamopsis tetragonoloba (L.) Taub.] is an important drought-tolerant legume crop widely cultivated in the semi-arid regions of India for food, fodder, and industrial uses. However, low soil fertility, particularly phosphorus deficiency, often limits its growth and productivity. The use of phosphorus fertilizers in combination with beneficial biofertilizers such as Rhizobium and phosphate-solubilizing bacteria (PSB) may improve nutrient availability and enhance crop performance under semi-arid conditions. A field experiment was carried out during Kharif 2025 at the Agronomy Research Farm, School of Agricultural Sciences, Jaipur national University, Jaipur, Rajasthan. The results indicated that among the phosphorus levels the higher growth parameters viz., plant height, number of branches plant-1 and dry matter accumulation; maximum yield attributes and yield viz., number of pods plant-1 (25.16), number of seeds pod-1 (7.12), 1000 grains weight (26.97 g), similarly, the maximum seed yield (1101 kg ha-1), straw yield (2257 kg ha-1) and biological yield (3358 kg ha-1) recorded significantly with the application of 60 kg P2O5 ha-1 and were at par with the application of 40 kg P2O5 ha-1 . However, among biofertilizer treatments, seed inoculation with Rhizobium + phosphate-solubilizing bacteria (Pseudomonas fluorescens) produced the highest growth, yield attributes, seed yield (997 kg ha⁻¹), straw yield (2054 kg ha⁻¹) and biological yield (3051 kg ha⁻¹). Whereas, harvest index was not significantly influenced by different phosphorus levels and the biofertilizer treatments. The study indicated that integrated application of 60 kg P₂O₅ ha⁻¹ along with Rhizobium and PSB was most effective for enhancing growth and productivity of cluster bean under semi-arid conditions of Rajasthan.