Effect of phosphorus and sulphur on growth and yield of summer mungbean [Vigna radiata (L) Wilczek]

A field experiment was carried out during summer 2010 and 2011 on a sandy clay loam soil to investigate the effect of varying levels of P and K on summer mungbean [(Vigna radiata (L) Wilczek]. The study revealed that application of 60 kg P2O5/ha resulted in significantly higher LAI (2.47) and chlorophyll content (3.01 mg/g) in leaf at flower initiation and taller plants (36.6 cm), greater dry matter accumulation (8.84 g/plant), seeds/plant (130) and test weight (34.7 g) at harvest over any of the lower P levels (0, 20, 40 kg P2O5/ha). Seed and straw yields were also significantly improved with 60 kg P2O5/ha to the tune of 14.4 and 14.1% over control, respectively. Sulphur at 45 kg/ha produced significantly higher LAI (2.32) and chlorophyll content (2.94 mg/g) at flower initiation and more dry matter accumulation (8.54 g/plant), seeds/plant (128.5) and test weight (34.7 g) at harvest over any of the lower levels of sulphur (0, 15 and 30 kg/ha). Seed and straw yields were also significantly improved with 45 kg S/ha by 14.4 and 13.1% over the control, respectively. Interaction effect of 60 kg P2O5/ha and 45 kg S/ha was significant in respect of LAI and chlorophyll content at flower initiation and dry matter accumulation and test weight at harvest.