Phytotoxic potential of Drimys brasiliensis Miers for use in weed control/Potencial fitotoxico de Drimys brasiliensis Miers para o controle de plantas daninhas

• Published in: Acta scientiarum. Agronomy 2015-10, p.505
• Main Authors: Anese, Simoni, Gualtieri, Sonia Cristina Juliano, Grisi, Patricia Umeda, Jatoba, Luciana de Jesus, Arduin, Marcos
• Format: Article
• Language: Spanish
• ISSN: 1679-9275
• DOI: 10.4025/actasciagron.v37i4.19476

This study aims to evaluate the phytotoxicity potential of leaf and root extracts of Drimys brasiliensis on the germination and seedling growth of Panicum maximum and Euphorbia heterophylla and its influence on metaxylem cell size in the seedling roots of the latter specie. The leaf and root extracts were fractionated by partition chromatography, and the hexane and ethyl acetate fractions obtained from each organ were evaluated at different concentrations for phytotoxic activity in several bioassays. In seedling growth tests, we compared the effects of these fractions with the herbicide oxyfluorfen. The hexane fraction of the root extracts showed a higher inhibitory potential on the germination and growth of weeds and reduced the average size of the metaxylem cells of E. heterophylla roots by more than 50%. The inhibitory effects of the root hexane fraction on seedling growth was similar to the herbicide, indicating that D. brasiliensis is a possible alternative form of control for the weed species examined. Keywords: allelopathy, inhibition, germination, early growth. O objetivo do estudo foi avaliar o potencial fitotoxico de fracoes do extrato de folhas e raizes de Drimys brasiliensis sobre a germinacao e o crescimento de plantulas de Panicum maximum e Euphorbia heterophylla, e sua influencia sobre as celulas do metaxilema da ultima especie. Os extratos de folhas e raizes foram fracionados por cromatografia de particao e as fracoes hexanica e acetato de etila obtidas de cada orgao foram avaliadas nos bioensaios, em diferentes concentracoes. No teste de crescimento, comparou-se o efeito das solucoes das fracoes com o herbicida oxyfluorfen. A fracao hexanica das raizes apresentou maior potencial para inibir a germinacao e crescimento das especies infestantes e ocasionou reducao em mais de 50% no tamanho das celulas do metaxilema de E. heterophylla. As inibicoes no crescimento inicial, decorrentes da aplicacao da fracao hexanica das raizes, foram similares ao efeito produzido pelo herbicida comercial, indicando a eficiencia de D. brasiliensis para o controle das especies infestantes estudadas. Palavras-chave: alelopatia, inibicao, germinacao, crescimento inicial.