Allelopathic effects of decomposing garlic stalk on some vegetable crops

This study was carried out to examine the allelopathic effects of decomposed stalk of three garlic cultivars on the growth of the receiver vegetable crops: namely tomato, Chinese cabbage, lettuce, carrot, cucumber and hot pepper in a pot trial. The results showed that all three garlic cultivars have different allelopathic effects and each cultivar showed different allelopathic effects upon different vegetable crops or the same vegetable crop at different concentrations of decomposed garlic stalk. The activities of protective enzyme SOD in receiver vegetable crops appeared first, increased and then decreased with the increasing content of decomposed garlic stalk. The MDA contents in the receiver vegetable crops showed an increasing trend; however, there was no apparent regularity on POD and CAT contents. In general, the decomposed stalk of three garlic cultivars showed allelopathic inhibitory effects on all the index of carrot and lettuce but promotion effects on Chinese cabbage. Therefore, among all the receiver vegetable crops in this study, Chinese cabbage was concluded to be optimal successive crop for garlic.