Determination of allelopathic effect of winter weeds on nutrient content and uptake in wheat

Abstract

Environmental contamination, herbicide resistance development among weeds and health concerns due to over and misuse of synthetic herbicides has led the researchers to focus on alternative weed management strategies. Allelochemicals extracted from various plant species can act as natural weed inhibitors. In this study, allelopathic aqueous extracts from Medicago denticulata, Chenopodium album and Melilotus indica as sole and combined application were tested for their effect on nutrient content and uptake in wheat by inhibiting the most problematic weed of wheat, Phalaris minor. The nitrogen, phosphorus and potassium content in grain and straw of wheat as well as straw of Phalaris minor gave non-significant results under various treatments. However, the variation in nitrogen, phosphorus and potassium uptake differ significantly at harvest for grain and straw of wheat, straw of Phalaris minor as well as total except for total phosphorus uptake. Nitrogen, phosphorus and potassium uptake by grain and straw of wheat under control condition was lower than under other treatments, respectively. It clearly showed the loss of nutrients due to crop weed (Phalaris minor) competition and the efficiency of allelochemicals in controlling Phalaris minor compared to control conditions as nitrogen, phosphorus and potassium uptake by wheat was found higher under treatments in which control of Phalaris minor was better. This indicated that effective weed control reduced competition between crops and weeds which resulted in better utilization of available nutrients by the crop plant.