Allelopathic Effects of Mungbean (Vigna radiata) on Subsequent Crops

Abstract

Mungbean contains allelochemicals that can either inhibit or promote the growth and yield of subsequent crops in certain cropping systems. To examine the role of mungbean in a cropping system, the allelopathic effects of mungbean on the seed germination and plant growth of subsequent crops were evaluated in laboratory and pot experiments. In the laboratory experiment, the allelochemicals in mungbean inhibited the germination and root length of lettuce, whereas it had no negative effect on Echinochloa crus-galli seed germination. The pot experiment revealed that allelochemicals from decomposed mungbean in soil reduced the seed germination and plant height of subsequent crops especially in soybean (Glycine max) and lettuce (Lactuca sativa). The seed germination of soybean and lettuce was severely inhibited while the plant height of Echinochloa crus-galli was reduced. A high performance liquid chromatogram of the allelochemical compounds from the mungbean root and stem was composed of one major peak that had a retention time identical to that of thioglycerol and four other different peaks with one of these peaks having a retention time similar to that of aglycone.