Weed control and rice yield stability studies across diverse tillage and crop establishment systems under on-farm environments

Abstract

In zero-till direct seeded rice (DSR), systematic information pertaining to weed management under on-farm conditions for medium- or long-term is lacking. Therefore, on-farm adaptive trials were conducted to find out the effect of different crop establishment and weed management practices on yield stability and weed dynamics over the years at Faridabad and Sonepat districts of Haryana, India. Results showed that DSR with residue (DSRR) coupled with pretilachlor as pre-emergence (PE) @ 0.75 kg ha−1 followed by bispyribac-sodium as post-emergence (POE) @ 0.025 kg ha-1 (PretBis) or cyhalofop butyl @ 0.060 kg ha-1 (PretCy) resulted in rice grain yield (5.38 t ha-1 and 5.33 t ha-1, respectively) statistically at par with transplanted rice (TPR)-PretBis (5.30 t ha-1) and TPR-PretCy (5.21 t ha-1). PretBis produced 32.3 % higher grain yield as compared to farmers’ practice (FP). Higher broad-leaved weeds (BLWs) biomass was recorded under DSR (8.25 g m-2), followed by DSRR (4.58 g m-2) and TPR (3.99 g m-2). Whereas, among weed management practices, PretBis had least BLWs biomass (4.17 g m-2) followed by PretCy (4.77 g m-2). Biomass of narrow leaved weeds (NLWs) and sedges was found lowest under PretCy (3.63 g m-2 and 3.77 g m-2). GGE biplot analysis of biomass of BLWs and NLWs reveals that PretBis and PretCy, respectively had the highest-ranking owing to their stability across the environments (location x year). In year x location environments, last three years of study were in the same mega environments, which indicated stability in weed biomass and population reduction from third year onwards. Yield stability was highest under DSRR-PretCy followed by DSRR-PretBis. The study highlights that, under north-western Indo-Gangetic plains, if the weeds are managed properly, DSRR can be adopted without significant yield reduction during initial years and comparable yield to TPR and improved soil fertility in the long-term.