ALLELOPATHIC POTENTIAL OF Tectona grandis L. ON THE GERMINATION AND SEEDLING GROWTH OF Vigna mungo (L.) Hepper

The allelopathic impact of Tectona grandis L. on the germination and seedling growth of Vigna mungo (L.) Hepper has been investigated in this experiment. Bioassay studies of the aqueous extracts of the leaves of T. grandis showed that seed germination and seedling growth of V. mungo were inhibited. In addition, the reduction of seed germination was found to be up to 48% at 10% concentration. At this concentration, the epicotyl showed 67.3% reduction in length when compared to the control. Consequently, the hypocotyl demonstrated 64.7% reduction in length. In pot culture experiments, a 4% aqueous extract of the leaves was found to inhibit seed germination and the growth of the seedlings. This concentration of leaf extracts reduced seed germination percentage to the tune of 70%. There was reduction in shoot length to about 33.3% and the root length about 54.3. Higher concentration of aqueous extracts of the leaves prevented seed germination. As for the biomass of V. mungo is concerned, aqueous extracts of the leaves of T. grandis caused a corresponding reduction.