Abstract: The methods of bioassay, pot experiment and water culture were adopted to explore the allelopathic effect of tomato on several plant acceptors. The results showed that tomato had an autotoxidity effect. Its aquatic extract could significantly inhibit the seedling growth of Cucumis sativas, Raphanus sativa, Lactuca sativa, Brassica perkiensis, Brassica oleracea, but its volatiles had no significant effect on that of Phaseolus aureus, Brassica perkiensis, Lactuca sativa, and tomato itself. After the tomato seedlings were transplanted for 40 days, their root exudates had a significant inhibition on the growth of Cucumis sativas, but no effect on Lactuca sativa. It is suggested that the autotoxidity effect of tomato is one of causes obstructing its continuous cropping, and tomato should be avoided to intercrop with Lactuca sativas in wateror shed culture.

Key words: Tomato, Allelopathy, Autotoxidity, C, N, P, K, winter wheat, maize straw, decomposition, rotation