Post-Emergence Herbicides Selection for Rotational Use in Puddle Transplanted Rice to Avoid Herbicide Resistance in Weeds

Background and Objective: Indiscriminate use of herbicide poses serious concern as it encourages herbicide resistance development in weeds and makes weed control a difficult task. The present study was undertaken with a view to select suitable post-emergence herbicides for puddle-transplanted rice. Materials and Methods: The experiment included ten post-emergence herbicides along with a weed-free control and a weedy check in a randomized complete block design with three replications. Results: The proprietary mixture of bispyribac sodium+bensulfuron methyl showed the best weed control efficacy (83%) followed by penoxulum (80%), proprietary mixture of bensulfuron methyl+quinchlorac (74%), ethoxysulfuran (63%) and pyrazosulfuran ethyl (54%). Satisfactory grain yields were obtained from proprietary mixture bispyribac sodium+bensulfuron methyl (5.28 t ha^–1), ethoxysulfuron (5.06 t ha^–1), proprietary mixture of bensulfuron methyl+quinchlorac (5.01 t ha^–1), penxosulum (5.0 t ha^–1) and 2,4-D amine (4.85 t ha^–1) while, pyrazosulfuron ethyl (3.55 t ha^–1) and MCPA500 (3.92 t ha^–1) showed the worst performance similar to that of the weedy plot (3.40 t ha^–1). Conclusion: The alternate use of any of the post-emergence herbicides like a proprietary mixture of bispyribac sodium+bensulfuron methyl, bensulfuron methyl+quinchlorac and single herbicide of ethoxysulfuron, pyrazosulfuran ethyl and penoxulum could be used effectively to control weeds in puddle transplanted rice.