Efeito alelopático de extratos vegetais sobre germinação e crescimento inicial do tomateiro

Abstract

Plant extracts are used in agriculture, in order to stimulate the development, production and disease control. The work aimed to evaluate the allelopatic activity of aqueous extracts of leaves Plectranthus barbatus and Aloe vera on germination and initial growth of tomato plants. Aqueous extracts were obtained from the leaves of P. barbatus and A. vera, at concentrations of 0, 2, 4, 8 and 16%. The experimental design was completely randomized design in factorial scheme 2 (plant extracts) x 5 (concentrations of extracts), with 4 repetitions. It was analyzed the influence of extracts on germination of tomato seeds on germitest paper moistened with respective extracts, in air-conditioned Chamber. The evaluation consisted of germination and germination speed index. For the experiment used emergency seeds imbibed in the extracts, sown in substrate suitable for seedlings. The evaluation consisted of emergency, emergency speed index and length of shoot and root of tomato plants. With the obtained results it is observed that occurs the aqueous extracts of P. barbatus and A. vera on germination and growth of tomato plants early. Aloe extract stimulates germination, emergence and length of aerial part of the plant. The highest concentration of 16%, of extracts of A. vera inhibit germination, germination speed index, root length and length of aerial part of the plant. Therefore, the extract of A. vera and P. barbatus in low concentrations, can be used as stimulants on germination and initial growth of tomato plants.