Water extract of Passiflora edulis SIMS on germination and initial growth of lettuce

Abstract

The Passionflower tree (Passiflora edulis Sims) and many other plants produce secondary compounds which are frequently released in the environment and may affect the development of other living beings such as neighboring plants. Current research evaluates possible allelopathic effects of the aqueous extracts of the leaf and the dry fruit of the passionflower tree on the germination of seeds and growth of lettuce seedlings. The aqueous extract was prepared with 50 g of dry matter (leaf and fruit) which was homogenized in 1000 mL distilled water (crude extract). Treatments, with five replications, consisted of the following proportions: 0, 25, 50 and 100%. Germination percentage and germination speed index were determined. Growth was quantified by length and fresh biomass of the root and of the aerial part. Leaf and fruit aqueous extracts affected negatively the lettuce’s germination process and inhibited the root growth. The two extracts stimulated the growth of the seedlings’ aerial part. Highest concentrations influenced the initial development and the germination of the lettuce seeds.