Influence of post-emergence herbicides on weeds and productivity of garden pea (Pisum sativum) under mid hill conditions of Himachal Pradesh

Abstract

To standardize dose and time of application of post-emergence herbicides in garden pea (Pisum sativum var. hortense) under mid-hills of Himalaya, eleven treatments viz., imazethapyr 100 and 150 g/ha at 20 and 40 DAS, quizalofop 25 and 37.5 g/ha at 20 DAS, isoproturon 1.0 and 1.25 kg/ha at 40 DAS, pendimethalin 1.5 kg/ha (pre- emergence), hand-weeding twice (30 and 60 DAS) and unweeded check were tested during the winter season of 2005-06 and 2006-07 at Palampur. The major weed flora was Phalaris minor, Avena fatua and Vicia sativa in both the years. Post-emergence application of all the herbicides except quizalofop 25 g/ha at 20 DAS and hand weed- ing twice resulted in significantly lower dry weight of weeds over pre-emergence pendimethalin 1.5 kg/ha. Higher doses of all the post-emergence herbicides were superior to their lower doses. Significantly lower dry matter accu- mulation of all the weed species and highest weed control efficiency were obtained with imazethapyr 150 g/ha (40 DAS). Imazethapyr 150 g/ha at 40 DAS resulted in maximum plant height, dry matter accumulation, crop growth rate, relative growth rate, nodule count and weight and green pod and haulm yields. Weeds in untreated check re- duced pea pod yield by 56.8% over the best post-emergence herbicidal treatment (imazethapyr 150 g/ha at 40 DAS) in 200506 and 60.1% in 200607.