Nutrient uptake by clusterbean as influenced by weed management and sulphur nutrition

A field experiment was carried out during two consecutive seasons of Kharif 2013 and 2014 to evaluate effect of weed management and sulphur nutrition on the nutrient uptake by weeds and crop in clusterbean [Cyamopsis tetragonoloba (L.) Taub.]. Minimum weed dry matter of narrow-leaved (239 kg/ha), broad-leaved (285 kg/ha) and total dry weight (524 kg/ha) was observed under hand weeding at 20 and 40 days after sowing (DAS), which was closely followed by the sequential application of preemergence application of pendimethalin 0.75 kg/ha followed by (fb) imazethapyr 0.075 kg/ha as postemergence. The highest seed (1.22 t/ha), haulm (2.44 t/ha) and biological yields (3.66 t/ha) was registered in hand weeded twice, which was statistically at par to pendimethalin fb imazethapyr. Hand weeding twice and pendimethalin fb imazethapyr, with non-significant difference between these two, saved N and P uptake by 56, 47 and 55, 46%, respectively, compared to weedy check in combined uptake of nutrient both by weeds and crop.