Naturally occurring phytotoxins in allelopathic plants help reduce herbicide dose in wheat

Field studies were carried out to evaluate the influence of allelopathic plant water extracts applied alone or tank-mixed with a reduced herbicide dose on the weeds of wheat. Water extracts of sorghum (Sorghum bicolor (L.) Moench.) + sunflower (Helianthus annuus L.) + mulberry (Morus alba L.) were used alone (each at 20 L ha(-1)) or combined with iodo + mesosulfuron (3.6 and 7.2 g active ingredient (a.i.) ha(-1); 25 and 50% of the recommended dose, respectively). The recommended dose of herbicide, a weedy check and a weed-free treatment were included for comparison. Allelopathic water extracts alone suppressed the density of canary grass (Phalaris minor Retz.) and wild oat (Avena fatua L.) by 34-42%, and dry weight by 59-67%. The mixture of allelopathic plant water extracts combined with reduced doses of iodo + mesosulfuron gave weed control equal to the recommended dose of the herbicide. Integration of plant water extracts with reduced herbicide rates provide effective weed control and a wheat yield comparable to using the recommended herbicide dose.