Allelopathic effect of common weeds on germination and seedling growth of rice in wetland paddy fields of Mizoram, India

Weed invasion of crops contested for environmental resources alongside releasing a certain chemical into the soil and thereby lowering yield potential. The possible allelopathic influence of aqueous extract from leaves and shoots of Alternanthera philoxeroides (Mart.) Griseb., Ludwigia octovalvis (Jacq.) P.H. Raven and Persicaria hydropiper (L.) Delarbe on germination and seedling growth of rice (Oryza sativa L.) was investigated in this study. To prepare the extract, powdered air-dried leaves and shoots of certain weeds were soaked in distilled water (1 : 10) for 24 h at room temperature, and a different dilution was made from the stock. Aqueous extracts from various plant parts were found to suppress seed germination and the development of rice seedlings. As the extract concentration increases, the intensity of inhibition on germination, shoot length, root length and dry matter reduction increases. The average percent inhibition (API) of leaf extract treatments, namely 8% and 10% A. philoxeroides, 8% and 10% L. octovalvis, and 10% P. hydropiper, was found to be greater than 45%. Shoot extracts containing 2% A. philoxeroides, 2% and 4% L. octovalvis, and 2% P. hydropiper have less than 15% average percent inhibition. According to the findings, different weeds contain allelochemicals of variable types and quantities, and different portions of the same weed have distinct effects on germination and rice seedling development.