A field experiment entitled “Effect of phosphorus, sulphur and biofertilizers on growth and yield of clusterbean [Cyamopsis tetragonoloba (L.) Taub.]” was conducted during kharif 2005 at the Instructional Farm, Department of Agronomy, Rajasthan College of Agriculture, Udaipur. The experiment consisted of 24 treatment combinations comprising three phosphorus levels (0, 30 and 60 kg P2O5 ha-1) and two sulphur levels (0 and 40 kg S ha-1) and four biofertilizers levels (control, Rz, PSB and Rz + PSB). The experiment was laid out in split plot design with three replications, keeping phosphorus and sulphur levels in the main-plots and biofertilizers in the subplots. The results indicated that fertilizer application upto 30 kg P2O5 ha-1 significantly improved branches plant-1 by 27.23 per cent and plant height by 17.67 cm over control. Dry matter accumulation by plant at 30, 60 DAS and at harvest, the crop under influence of 30 kg P2O5 ha-1 accumulated 23.15, 27.31 and 31.02 per cent higher biomass over control. Chlorophyll content at 50 % flowering and total number of effective nodules plant-1 showed significant response upto 30 kg P2O5 ha-1, which were 5.79 and 20.48 per cent higher compared to control. The yield attributes, namely pods plant-1, seed pod-1, test weight and seed yield plant-1 showed significant response upto application of 30 kg P2O5 ha-1. Significant improvement in seed, haulm and biological yield was recorded upto application of 30 kg P2O5 ha-1. The magnitude of increase in aforesaid yield parameters were to extent of 38.46, 32.34 and 34.17 per cent, respectively over control. Application of 30 kg P2O5 ha-1 significantly enhanced P content of seed and haulms over control by 9.09 and 8.92 per cent, respectively, but gum content of seed was significantly higher at 60 kg P2O5 ha-1 by 5.35 and 9.54 per cent over 30 kg P2O5 ha-1 and control. Uptake of nitrogen, phosphorus and sulphur by seed, haulms and total showed significant increase upto 30 kg P2O5 ha-1 over control. Application of fertilizer upto 30 kg P2O5 ha-1 recorded significantly higher net returns over control by Rs. 7843 ha-1. Similarly, application of 30 kg P2O5 ha-1 fetched higher B:C (2.96) which was found at par with 60 kg P2O5 ha-1 (2.77). and 9.05, 8.11, 16.41 cm, respectively. Combined microbial inoculation significantly improved dry matter accumulation (beyond 30 DAS) at 60 DAS and harvest over control, Rz and PSB inoculation by 16.4, 7.16, 5.41 and 18.61, 8.51, 7.75 per cent, respectively. Chlorophyll content and total number of effective nodules plant-1 were highest when seeds were inoculated with Rz + PSB, which was significantly higher over control by 9.90 and 14.71 per cent, respectively. Amongst yield attributes, dual inoculation recorded highest number of pod plant-1, seed pod-1 and seed yield plant-1 which were at par with single inoculation of Rz and PSB and all these recorded significant increase over control. Dual inoculation with Rz + PSB produced highest seed, haulm and biological yield (16.99, 39.08 and 56.07 q ha-1) which were significantly higher over control, Rz and PSB by 24.65, 9.96, 8.21 and 22.54, 9.77, 7.83 and 23.17, 9.83, 8.44 per cent, respectively. Amongst inoculants, Rz + PSB proved most efficient in improving N and P content of seed, haulms and protein as well as gum content of seed over control by 18.25, 17.17 (N) 15.78, 17.64 (P) and 18.54, 10.21 per cent, respectively. Dual inoculation with Rz + PSB proved economically beneficial as it recorded highest net returns of 2304, 2755 and 5974 ha-1 over PSB, Rz alone and control. Similarly, it increased B:C to 2.95 compared to 2.21, 2.61 and 2.66 fetched under no inoculation, Rz and PSB alone, respectively.
Effect of phosphorus, sulphur and biofertilizers on growth and yield of clusterbean [Cyamopsis tetragonoloba (L.) Taub.]