Effect of individual or combined application of herbicide imazethapyr on nutrient uptake by blackgram (Vigna mungo l.)

Abstract

A field experiment was conducted to study the influence of individual or combined application of imazethapyr herbicide on nutrients depletion by weeds in black gram at Berthin, Bilaspur district of Himachal Pradesh, India. Twelve weed control treatments viz., imazethapyr at 70 & 80 g/ha as pre-emergence and 3-4 leaf stage, ready mix combination of imazethapyr + imazamox70 & 80 g/ha as pre-emergence and at 3-4 leaf stage, pendimethalin at 1000 g/ha as pre-emergence, ready mix combination of imazethapyr + pendimethalin 1000 g/ha as pre-emergence, hand weeding twice (25 &45 DAS) and unweeded check were tested in a randomized block design (RBD) with three replications to determine the most efficient treatment. The results of the study revealed that the NPK uptake by blackgram was enhanced on the application of all weed management treatments. Further, a reduction in the depletion of the nutrients by weeds was also reported in all treatments. Among the various treatments, pre-emergence application of ready mix compound imazethapyr + imazamox 80 g/ha was found the best treatment, this was followed the combined application of imazethapyr + imazamox 70 g/ha, these two do not significantly different to each other. Overall, a higher uptake of nutrients by weeds in weedy checks tended to decrease available NPK in soil necessitating the control of weeds in the production system.