Impact of Weed Management Practices and Phosphorus Levels on Nutrient Uptake and Quality of Clusterbean (Cyamopsis tetragonoloba L.)

A field experiment was conducted during Kharif 2013 at Agronomy farm, S.K.N. College of Agriculture, Jobner, Jaipur (Rajasthan) to evaluate the impact of weed management practices and phosphorus levels on nutrient uptake and quality of clusterbean crop. The treatments comprising 6 weed control treatments (Weedy check, one HW at 20 DAS, two HW at 20 and 40 DAS, pendimethalin at 0.75 kg/ha, imazethapyr at 100 g/ha and fenoxoprop-p-ethyl at 70 g/ha and four levels of phosphorus (0, 20, 40 and 60 kg/ha) assigned to main and sub plots of spilt plot design, respectively and replicated thrice. Hand weeding twice at 20 and 40 DAS, imazethapyr at 100 g/ha, and one HW at 20 DAS were found statistically similar and significantly better treatments in enhancing nutrient concentration in grain and stover, protein content in grain, and reduction in nutrient depletion by weeds but in enhancing of nutrient uptake by crop, two hand weeding at 20 and 40 DAS was found significantly better treatment over rest of the treatments. Application of 60 kg P/ha in clusterbean recorded the highest N, P, and K concentration in weeds and nutrient depletion by weeds at the harvest stage. Every increase in the level of P to 40 kg/ha resulted significant improvement in N, P and K uptake by grain and stover, protein content and phosphorus use efficiency.