Studies on root phenology, productivity and economics of wetland rice (Oryza sativa L.) as influenced by establishment methods and weed management practices

A field experiment was conducted at farmers’ field in West Garo Hills district of Meghalaya, India during kharif 2010 and 2011 to study the root characteristics of rice under different establishment methods and integrated weed management practices. Results revealed that the length, volume and biomass of roots were higher in SRI method followed by ICM method than CRC system at physiological maturity stage during both the years of investigation. Hand weeding twice at 20 and 40 DAT followed by butachlor 50 EC@1.5 kg a.i.ha-1 at 3 DAT + mechanical weeding at 20 DAT recorded higher root parameters over unweeded control during both years of field study. Maximum grain yield of rice was recorded with SRI method of establishment followed by ICM. Among the weed management practices, hand weeding twice at 20 DAT and 40 DAT recorded significantly higher grain yield closely followed by butachlor 50EC@1.5 kg a.i. ha-1 at 3 DAT + one mechanical weeding at 20 DAT. The higher net profit and B:C ratio  under SRI establishment method of wetland rice could be obtained with butachlor 50 EC@1.5 kg a.i. ha-1 at 3 DAT + mechanical weeding at 20 DAT followed by hand weeding twice at 20 and 40 DAT. In ICM higher grain yield was recorded with hand weeding twice at 20 and 40 DAT.