Weed management through cover crop mulching and herbicide application on growth and yield of rabi maize

SWAPNA S. HITTALAMANI; S. RAJKUMARA; P. ASHOKA; MANJUNATHA HEBBARA

SWAPNA S. HITTALAMANI Department of Agronomy, College of Agriculture, University of Agricultural Sciences, Dharwad - 580 005, India
S. RAJKUMARA Department of Agronomy, College of Agriculture, University of Agricultural Sciences, Dharwad - 580 005, India
P. ASHOKA Department of Agronomy, College of Agriculture, University of Agricultural Sciences, Dharwad - 580 005, India
MANJUNATHA HEBBARA Department of Soil Science and Agricultural Chemistry College of Agriculture, University of Agricultural Sciences, Dharwad - 580 005, India

Keywords: Covercrops, Maize, Mulching, Pre-emergence, Pendimethalin

Abstract

A field experiment was conducted at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, Karnataka during rabi, 2022-23 on Vertisols to study the effect of cover crop mulching and herbicide application on weeds, growth and yield of rabi maize. The experiment was laid out in a split plot design with three replications. The main plots consisted of two cover crops with two mulching periods i.e., cowpea and sunhemp at 30 and 45 DAS. The subplot consisted of four treatments with herbicide application rates viz., no herbicide, pre-emergence application of pendimethalin 1, 0.75 and 0.5 kg a.i. ha-1. In the maize + sunhemp (1:2) system mulching of sunhemp at 45 DAS with preemergence application of pendimethalin1kg a.i. ha-1reduced the dry weight of weeds at 40 and 60 DAS (6.53 and10.13 g m-2, respectively) and enhanced the weed control efficiency (87.7 and 83.3%, respectively) over other treatments. While, cowpea mulching at 30 DAS with pendimethalin 1 kg a.i. ha-1 recorded significantly lower weed index (6.0%) and higher cob length (16cm), hundred grain weight (28.7 g), grain yield per plant (124.5 g), grain yield (5267 kg ha-1), stover yield (6955 kg ha-1), gross returns (`1,05,852 ha-1), net returns (`60,019 ha-1) and B:C ratio (2.18). This was on par with cowpea mulching at 30 DAS with pendimethalin 0.75 kg a.i. ha-1. The weed free check recorded a higher grain yield of 5600 kg ha-1, while the weedy check resulted in lower yields.