WEED PERSISTENCE, CROP RESISTANCE AND PHYTOTONIC EFFECTS OF NEW MOLECULE HERBICIDES IN TRANSPLANTED RICE

Abstract

Weeds reduce rice yield as well as impair grain quality. To address the problem, a field experiment was conducted at the Bangladesh Rice Research Institute, Bangladesh during dry season of 2018, with the aim to identify the phytotonic effect of herbicides on weed and rice growth for sustained production in transplanted rice. The weed management treatments were the combination of pre and post emergence herbicide viz., mefeneset + bensulfuron methyl fb cyhalofopbutyl, mefeneset + bensulfuron methyl fb bispyribac sodium, bensulfuron methyl + acetachlor fb ethoxysulfuron, pretilachlor + trisulfuron 2% + penoxlum, weedy check (unweeded), weed free by 3 HW. Results showed that the herbicide mefeneset + bensulfuron methyl + bispyribac sodium produced the lowest weed number and biomass of which weed control efficiency showed 93%. The treatment having mefeneset + bensulfuron methyl + bispyribac sodium had higher value of HEI (Herbicide efficiency index), CRI (Crop resistance index) and lower value of WPI (Weed persistence index) and WMI (Weed management index) than other weed management treatments. Yield and yield attributing parameters, and weed dynamics were significantly affected and the trend of higher production was influenced by the weed management practices. Among the weed management practices, mefeneset + bensulfuron methyl + bispyribac produced the highest grain yield.