Allelopathic effect of leaf debris, leaf aqueous extract and rhizosphere soil of Ophiopogon japonicus Ker‐Gawler on the growth of plants

Abstract

Laboratory and greenhouse experiments were conducted to evaluate the allelopathic potential of dwarf lily turf (Ophiopogon japonicus Ker‐Gawler) on lettuce, alfalfa, timothy and mustard plant growth. Dry leaf debris, aqueous extract of fresh leaves and O. japonicus grown soil were investigated. Emergence, dry weight, and root and shoot length of all bioassay species were inhibited when grown in soil incorporated with oven‐dried leaves of O. japonicus. The inhibitory effects were often dependent on the concentration. However, the degree of inhibition varied among the test plant species. The aqueous leaf extract was highly phytotoxic and it significantly reduced germination, seedling growth, and the fresh weight of all the test species at all rates. The emergence and growth of all four tested plants were severely inhibited when planted in O. japonicus contaminated soil. These results indicate that O. japonicus incorporated leaf debris, leaf aqueous extract and its rhizosphere soil suppress seed germination, radicle growth, seedling emergence and seeding growth of certain weeds and suggest that these responses were attributed to an allelopathic effect.