Influence of variety and weeding regime on the yield of transplant aman rice

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the effect of variety and weeding regime on the yield of transplant Aman rice. The experiment consisted of three cultivars BRRI dhan49, BRRI dhan51 and BRRI dhan52 and six different weeding regimes such as no weeding, one hand weeding at 30 DAT, two hand weedings at 30 DAT and 45 DAT, three hand weedings at 30 DAT, 45 DAT and 60 DAT, application of Rifit 500 EC at 7 DAT and application of Rifit 500 EC at 7 DAT + One hand weeding at 30 DAT. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Nine weed species belonging to five families infested the experimental plots. Weed population and weed dry weight were significantly affected by cultivar and weeding regimes. The maximum weed growth was noticed with the dwarf cultivar BRRI dhan51 and minimum with taller cultivar BRRI dhan52. BRRI dhan49 produced the higher grain and the straw yields. The highest loss of grain yield was obtained in no weeding treatment and the lowest was obtained in Rifit 500EC at 7 DAT + one hand weeding at 30 DAT treatments. The highest number of effective tillers hill-1, number of grains panicle-1, 1000-grain weight were observed in Rifit 500EC at 7 DAT + one hand weeding at 30 DAT treatment. Application of Rifit 500EC at 7 DAT + one hand weeding at 30 DAT was more effective and economic than the other weed control treatments in controlling weeds and in producing higher grain yield. So, in order to control weeds effectively and to get the economic yield in transplant Aman rice, application of Rifit 500EC at 7 DAT + one hand weeding at 30 DAT might be recommended.