EFFECTS OF 5-AMINOLEVULINIC ACID ON GROWT H OF PLANT SEEDLINGS

Recently, we have found that 5-aminolevulinic acid (ALA) has plant gro wth regulating properties in lower concentrations besides herbicidal p roperties in higher concentrations. To clarify these properties, the i nfluence of ALA under different application methods and their concentr ations were examined using plant seedlings : rice, corn, kidney bean a nd radish. The results showed that the effects of ALA depended on the application method and their concentrations. The appropriate applicati on of ALA increased the growth of seedlings to 110-150%, and the optim um concentrations were 0.1-1 ppm on a root soaking, 30-100 ppm on a fo liar spray and 10-100 g/10 a on a soil treatment, respectively. Althou gh herbicidal properties at high concentrations has been reported to b e different among plant species, the difference of the promotive effec ts of ALA at low concentrations between monocotyledon and dicotyledon was found to be negligible in this study. Moreover, ALA was also an ea sy biodegradable substance in soil.