Effect of integrated weed-management practices on growth and yield of wet-seeded rice (Oryza sativa) and their residual effect on succeeding pulse crop

Abstract

A field experiment was conducted at Agricultural College and Research Institute, Madurai during winter (rabi) seasons of 1998-99 and 1999-2000, to study the effect of integrated weed-management practices on weed control and yield of wet-seeded rice. Glyphosate (1.5 kg a.i./ha) was applied at pre-sowing stage alone or in combination with pre-emergence application of pretilachlor + Safener (0.4 kg a.i./ha) and early post-emergence application of butanil (3 litres/ha) along with manual weeding. It was compared with weed-free check and unweeded control. All the weed-management practices significantly reduced the weed density of grasses, sedges and broad-leaf weeds, resulting in their reduced dry weight. Pre-sowing application of glyphosate (1.5 kg a.i./ha) effectively reduced the sedges, when combined with pre-emergence application of pretilachlor + Safner (0.4 a.i./ha) followed by two hand-weedings at 25 and 45 days after sowing. These recorded lesser weed density, dry weight and higher weed-control efficiency, resulting in higher grain yield (58.73 q/ha). Bioassay showed no residual effect of the herbicides applied to rice (Oryza sativa L.) on the stand of succeeding crop of blackgram [Phaseolus mungo (L.) Wilczek].