Allelochemicals are a major reason for replanting problem of asparagus. The effects of potential allelochemicals on the growth of asparagus cultivars UC157 and Gijnlim in replant culture were investigated. Their contents were determined by high-performance liquid chromatography, and their phytotoxicity was assessed in agar medium during the replanting time. Organic acids, oxalic, succinic and tartaric, were the main identified allelochemical compounds of the asparagus cultivars. The second replanting produced a higher concentration of total allelochemicals than the first. In general, root and shoot biomasses were inhibited by up to 81% and 68%, respectively, in the second replanting of UC157. The inhibition of lettuce growth by oxalic, succinic and tartaric acids was also investigated using a bioassay. The inhibitory concentration (IC50) and the effects of these allelochemicals indicated that these acids might have an important function in the allelopathic responses of asparagus replanting problem.
- Growth inhibition