FITOTOXICIDADE DA ESPECIE Ipomoea asarifolia (Desr.) Roem. & Schultz NO CONTROLE DE PLANTAS DANINHAS

Abstract

To minimize the impacts on agriculture due to weeds, in recent years the search for herbicides that cause less environmental damage has been growing. One of these searches are the plants that can synthesize phytotoxins that present inhibitory activity or growth of other plants, which enables a new alternative for sustainable agriculture. In this sense, the objective of this study was to evaluate the phytotoxic potential of Ipomoea asarifolia, in the inhibitory control and growth of the weed Leucaena leucocephala. The botanical materials were collected, dried, crushed and used for the preparation of the crude extracts by means of ethanolic maceration, decoction. Partition was performed to obtain the organic and aqueous fractions. The experimental design was entirely randomized with 7 treatments and 5 repetitions and the data were applied to ANOVA and Tukey's test at 1% probability for multiple comparisons. It was observed that the species I. asarifolia presents secondary metabolites capable of performing allelopathic activity on the seeds of L. leucocephala and the compounds flavonoids, anthocyanins and condensed tannins were identified. In addition, it was found that the seeds of leucena show a greater sensitivity to the ethanolic extract obtained from the leaves of I. asarifolia, so that the allelochemicals present increase the inhibition as the concentration of the extracts also increases. Therefore, the results indicate Ipomoea asarifolia has a high allelopathic potential to develop methods aimed at controlling the germination and development of Leucaena leucocephala as well as decrease the toxic actives used in agriculture to control it.