Vol. 11, Issue 9 (2022)

Author(s):
Kamble Anand Shankar, Channabasavanna AS and Mahadevswamy

Abstract:
The experiment was conducted for two consecutive years 2017-18 and 2018-19 to study to study the efficiency of new formulation of pre-emergence herbicide clomazone 50 EC on growth and development of HDPS cotton with better weed management in a cost effective manner. Clomazone 50 EC was tried in three different doses, viz. 250, 500 and 750 g a.i. ha^-1 concentrations and was compared with pendimethalin 680 g a.i. ha^-1, post-emergence herbicides such as, pyrithiobac sodium 10 EC and quizalofop ethyl 5 EC @, cultural; method like one HW at 25 DAS and IC at 50 and 75 DAS, weed free check, unweeded control and other integrated methods. The data indicated that pre emergence application of pendimethalin 38.7 CS @ 680 g a.i. ha^-1 and clomazone 50 EC @ 250 g a.i. ha^-1 as PE with one HW at 25 DAS and IC at 50 DAS (30.6 and 29.6) were on par with each other and recorded significantly lower soil dehydrogenase activity over reduced the microbial population (Bacteria, Fungi and Actinomycetes) and dehydrogenase and phosphatase activity significantly over the treatments where no herbicides was applied (one HW at 25 DAS and IC at 50 DAS, weed free check and unweeded control were on par with each other (33.8, 33.7 and 32.2). While the values were on par at 100 DAS and at harvest which indicated that the herbicide effect not persist for longer time as the herbicides degraded in soil by microbes as the herbicides were used as the carbon source for multiplication. The seed cotton equivalent yield was higher when herbicides were used indicating no adverse effect of the herbicide.