Integrated weed management on growth and yield of transplanted rice and its residual effect on succeeding black gram

Abstract

Rice is the most important cereal crop which plays major role in Indian food economy as well as dietary needs of the world. A major hindrance in the successful cultivation of rice is heavy infestation of weeds. Hence, the field investigations were carried out at Tamil Nadu Rice Research Institute, Aduthurai during wet seasons of 2011-12 and 2012-13 to study the effect of integrated weed control on growth and yield of transplanted rice and its residual effect on succeeding black gram. Experiments were tested in randomized block design replicated thrice. Treatments consisted of application of herbicides viz., clomazone 500 g ha-1, clomazone + 2, 4-DEE 500 g ha-1, butachlor 1250 g ha-1, pretilachlor 500 g ha-1 and bispyribac sodium 25 g ha-1 followed by (fb) Hand Weeding (HW) on 45 Days After Transplanting (DAT). Pre plant incorporation of glyphosate 2.5 L ha-1 fb pre emergence application of bensulfuron methyl plus pretilachlor 660 g ha-1 was also tested with two hand weedings and unweeded control. The highest grain yield (5831 and 8783 kg ha-1) were recorded under two hand weedings during both years as a result of reduced weed dry weight and increased growth attributes. This was on par with application of bispyribac sodium 25 g ha-1 fb one HW (5613 and 8653 kg ha-1). The results indicated that herbicides applied in rice did not showed their residual effects on succeeding black gram. Even though the results of two hand weedings were better, it can not be recommended at larger scale as it is time consuming and laborious. Hence, post emergence application of bispyribac sodium 25 g ha-1 fb one HW on 45 DAT can be recommended for better weed control and productivity in transplanted rice. © 2013 Asian Network for Scientific Information.