Assessment of allelopathic potential of root exudate of rice seedlings

To determine the allelopathic potential of root exudate from early developm ental stage of rice (Oryza sativa L), 6-d-old seedlings of eight cultivars were grown with 3-d-old alfalfa (Medicago sativa L.), cress (Lepidium sativ um L.) or lettuce (Lactuca sativa L.) seedlings in Petri dishes under contr olled condition. All rice cultivars (cv. Norin 8, Kamenoo, Nipponbare, Kinu hikari, Koshihikari, Sasanishiki, Yukihikari and Hinohikari) inhibited grow th of roots, shoots and fresh mass of alfalfa, cress and lettuce seedlings. Effectiveness of cv. Koshihikari was the greatest and more than 60 % inhib ition was recorded in all bioassays, followed by that of cv. Norin 8 of whi ch effectiveness was more than 40 %.