Allelopathic potentials of rice (Oryza sativa L.) cultivars leaves, straw and hull extracts on seed germination of barnyardgrass (Echinochloa crus-galli L.)

High crop competitive ability is an important component of integrated weed management. Allelopathic compounds released by rice (Oryza sativa L.) could help enhance its competitive ability and improve weed management. This study aimed to screen rice genotypes for allelopathic activity and to identify the potential parental lines for QTL analysis. Therefore, a total of 41 cultivars from germplasm collections in Turkey were evaluated for their allelopathic effects. Significant differences were found among the rice cultivars in their ability to reduce barnyardgrass (E. crus-galli) root growth and root dry weight accumulation. Root length inhibition ranged from 0.7% to 38.8%, respectively. The 'Marateli' and 'Koral' cultivars inhibited the root length by 38.8% and 31.2%, respectively. However, 'Arko', 'Edirne', 'Kirkpinar' and 'Sumnu' stimulated the root length and dry weight than control. Rice tissue extracts had variability to inhibit the E. crus-galli germination, the 'Marateli' leaf extracts were most inhibitory to germination. The 'Kiziltan', 'Koral' and 'Marateli' were identified for breeding of rice cultivars with higher allelopathic potential. Development of rice cultivar with proven allopathic characteristics could provide an environmentally friendly and low-cost approach for E. crus-galli control.