Efficiency of pre and post emergence herbicides with mechanical weeding on direct seeded rice in north western zone of Tamil Nadu

Abstract

The field experiments were conducted to study the effect of pre and post emergence herbicide with mechanical weeding on growth and yield of direct-seeded rice (DSR) at Regional Research Station, Tamil Nadu Agricultural University, Paiyur, Tamil Nadu, India in Navarai seasons of 2015 - 2016 and 2016 - 2017 in randomized block design with three replications. The weed management practices, viz. PE Application of Pyrazosulfuron ethyl 10% WP @ 20 g ha-1 at 3 DAS + POE Bispyribac sodium 10% EC @ 25 g ha-1 (T1) at 2 - 3 leaf stage of weed recorded higher grain and straw yield of 5702 and 6047 kg ha-1 respectively followed by PE Pretilachlor 50% EC @ 0.5 kg ha-1 + PE Pyrazosulfuron ethyl 10% WP @ 10 g ha-1 at 7 DAS + POE Bispyribac sodium 10% EC @ 25 g ha-1 recorded grain and straw yield of 5531 and 5865 kg ha-1 respectively. Control (Unweeded check) recorded lower grain and straw yield of 4149 and 4614 kg ha-1 respectively. With respect to economic analysis, application of PE Pyrazosulfuron ethyl 10% WP @ 20 g ha-1 at 3 DAS +POE Bispyribac sodium 10% EC @ 25 g ha-1 (T1) recorded higher gross income of Rs. 83218, net income of Rs. 47657 with the BC ratio of 2.33 followed by PE Pretilachlor 50% EC @ 0.5 kg ha-1 + PE Pyrazosulfuron ethyl 10% WP @ 10 g ha-1 at 7 DAS + POE Bispyribac sodium 10% EC @ 25 g ha-1 at 2 - 3 leaf stage of weed recorded gross income of Rs. 80703, net income of Rs. 44970 with the BC ratio of 2.25. Control (Unweeded check) recorded lower gross income of Rs. 60808, net income of Rs. 30254 with the BC ratio of 1.98 The crop growth parameters like germination (%), plant height and no. of tillers and yield attributes (no. of panicle (m-2), Panicle length (cm), no. of grains panicle-1,no. of in filled grains panicle-1,test weight(g),grain yield (kg ha-1) and straw yield (kg ha-1) were also highest in this weed management practice.