Herbicide options for weed management in sugarcane + wheat intercropping system in indo-gangetic plains

Field and farmer participatory trials were conducted from 2006–07 to 2012–13 to evaluate the efficacy of herbicides alone and in combination on complex weed flora in sugarcane + wheat intercropping system. Sulfosulfuron 25 g/ha, sulfosulfuron + metsulfuron (ready-mix) 32 g/ha, mesosulfuron + iodosulfuron (ready-mix) 14.4 g/ha, pinoxaden 50 g/ha, pinoxaden + metsulfuron 50 + 4 g/ha, pinoxaden + 2,4-D 50 + 500 g/ha, pinoxaden fb carfentrazone 50 fb 20 g/ha gave satisfactory control of Phalaris minor. However, pinoxaden treatments were superior to other herbicides in respect of grassy weed management. For control of broad-leaf weeds, tank-mix of metsulfuron or 2,4-D with pinoxaden were found effective. Ready-mix herbicides sulfosulfuron+ metsulfuron and mesosulfuron+ iodosulfuron were also found promising against complex weed flora in sugarcane + wheat intercropping system. Clodinafop 60 g/ha, fenoxaprop 100 g/ha and carfentrazone 20 g/ha were phyto-toxic to the sugarcane. Grain yields of wheat under sulfosulfuron, sulfosulfuron + metsulfuron (ready-mix), mesosulfuron + iodosulfuron (ready-mix), pinoxaden alone and in combination with metsulfuron, 2,4-D or carfentrazone were as good as weed free check. Similarly the cane yields under these treatments except pinoxaden fb carfentrazone and sulfosulfuron + metsulfuron (ready-mix) were at par with each other and also with weed free check. Sulfosulfuron 25 g/ha, sulfosulfuron+ metsulfuron (ready-mix) 32 g/ha, mesosulfuron+ iodosulfuron (ready-mix) 14.4 g/ha or pinoxaden 50 g/ha provided effective control (83–97%) of weeds including Phalaris minor over the years. These treatments provided higher grain yield of wheat (4.65–4.93 t/ha) and cane yield (85.5–91.1 t/ha) of sugarcane.