2019 ASHS Annual Conference

Allelochemical can inhibit or stimulate growth and development of nearby plants of the same or other species. Ficus microcarpa L.f. is the plant that produces one or more these biochemical. Allelopathic effect of water extract from fresh biomass of F. microcarpa on germination and initial growth of Cosmos sulphureus Cav., Tagetes patula L. and Zinnia elegans Jacq. were investigated. Extract from leaf, fruit and root in the concentration of 25, 75, 125 and 175 g/L were applied to the seeds in petri dishes. The results revealed that germination and initial growth of three species were significantly inhibited by the F. microcarpa extract. Generally, the germination percentage and initial growth of three plants decreased as extract concentrations increased. The allelopathic sensitivity of three plants was Z. elegans > T. patula > C. sulphureus. Fruit extract showed the stronger allelopathy ability than that of leaf and root and Z. elegans was even killed by fruit extract when the concentration was more than 125 g/L. Leaf extract had less allelopathic effect on T. patula (germinated at 77 to 79%, 76% for the control), C. sulphureus (60-73%, 63%), and Z. elegans (77-85%, 97%). As the concentration from fruit extract increased from 25 to 175 g/L, the germination percentage decreased from 69 to 39% for C. sulphureus, 76 to 10% for T. patula, and 87 to 0.7% for Z. elegans. To design or plant a garden with Z. elegans, gardeners should not sow its seeds under or near F. microcarpa, especially during the fruit-dropping season.