A alelopatia é o efeito de uma planta sobre outra por intermédio da produção de compostos químicos que são liberados no meio ambiente. Portanto, objetivou-se identificar os efeitos alelopáticos de extratos voláteis de óleos essenciais de colônia (Alpinia zerumbet (Pers.) B. L. Burtt. & R. M. Sm.), goiaba (Psidium guajava L.) e nim (Azadirachta indica A. Juss) na germinação e no comprimento da raiz de plântulas de tomate (Lycopersicum esculentum). Os óleos foram extraídos das folhas de plantas adultas, por arraste a vapor de água. Foram utilizadas cinco concentrações de cada óleo (0,0; 0,25; 0,50; 0,75 e 1,0%, v/v), em delineamento inteiramente casualizado, com quatro repetições de 25 sementes. Para o teste de germinação foram avaliados os parâmetros: porcentagem de germinação (G%) e índice de velocidade de germinação (IVG). Para o crescimento inicial foram avaliados o comprimento da radícula (CR) e o comprimento da parte aérea (CPA). O óleo de colônia inibiu a germinação na concentração de 1%, bem como reduziu o IVG; nas concentrações de 0,75% e 1% inibiu totalmente o comprimento radicular e o comprimento da parte aérea. Para o óleo de goiaba houve redução na germinação com o aumento das concentrações.
This study aimed to identify and quantify the weed species in an area of organic acerola cultivation in the Distrito de Irrigação dos Tabuleiros Litorâneos do Piauí (DITALPI) in Parnaíba, Piauí, Brazil. Phytosociological sampling was completed in the rainy season, before the farmers adopted management techniques for the plants. Thirty plots of 0.25 m2 were sampled. The plots were located between crop rows, which consisted of herbaceous-subshrub plants. The absolute and relative covers and the absolute and relative frequencies of each species were calculated based on the occurrence and cover of each species. In total, 25 species comprising 13 families were registered, among which the Poaceae family that presented the largest number of species. Commelina benghalensis occurred the most frequently overall. Shannon’s diversity index (H’) and evenness were calculated as 2.30 nats ind-1 and 0.69, respectively. Five species accounted for 79.33% of absolute cover at DITALPI. The species were distributed heterogeneously within the field, and Commelina benghalensis, Urochloa plantaginea, Panicum maximum, Amaranthus spinosus, Cynodonsp., and Cyperus aggregatus were the species most likely to infest the acerola crop. As DITALPI is an area of organic cultivation, understanding these species is essential to help farmers select the best form of control.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.