Effect of Pre and Post Emergence Herbicides on Weed Control in Maize (Zea mays L.)

Abstract

A field experiment was conducted to study the effect of pre and post emergence herbicides on weed control in maize (Zea mays L.) in clay loam soils on farmer’s field in Hale Torgal village of Ramdurg taluk, Belgaum district during 20102011 under rainfed conditions. The experiment was laid out in randomized block design with three replications and ten treatments. Treatment combinations consisted of pre emergence application of atrazine 50 WP (1.25 kg ha -1 ) followed by (fb) post emergence application of atrazine 50 WP (1.50 or 1.75 kg ha -1 ), directed spray of paraquat 24 SL (1.0 or 1.5 kg ha -1 ), glyphosate 41SL (2.5 or 3.0 kg ha -1 ) and 2,4-D 80 WP (2.0 or 3.0 kg ha -1 ) along with standard check (Atrazine 50 WP 1.25 kg ha -1 + 2 intercultivation (at 30 and 45 DAS) + 1 hand weeding (between 30 and 45 DAS) and weedy check. Weedy check recorded the highest dry weight of the weeds whereas lowest was recorded in Atrazine 50 WP (1.25 kg ha -1 ) fb glyphosate 41SL (2.5 kg ha -1 ). Total number of weeds, weed control index followed the same trend. The higher maize yield was obtained with atrazine 50 WP 1.25 kg ha -1 fb glyphosate 41SL 2.5 kg ha -1 (5305 kg ha -1 ) whereas weedy check recorded significantly lower maize yield (2342 kg ha -1 ). The economics of weed management practices indicated that application of atrazine 50 WP (1.25 kg ha -1 ) fb glyphosate 41SL (3.0 kg ha -1 ) resulted in higher net returns (Rs 60702 ha -1 ) and B: C (3.76) compared to rest of the treatments.