PROMOTION OF PLANT-GROWTH BY POLYMERS OF LACTIC-ACID

Polymers of L-lactic acid are shown to promote plant growth. Dry weight of duckweed (Lemna minor L.) and corn (Zea mays L) was more than doubled when plants were grown in media containing the dimer of L-lactic acid, L-lactoyllactic acid. Higher polymers were equally effective at increasing plant biomass. Monomeric lactic acid and polymers of D-lactic acid showed no biological activity. Increased plant biomass was accompanied by increased chlorophyll accumulation and root growth. Promotion of chlorophyll accumulation and biomass may be due to increased ability to assimilate nutrients as plants treated with L-lactoyllactic acid showed no decrease in biomass when grown in medium that was growth limiting for control plants. © 1990 Kluwer Academic Publishers.