Potencial alelopático de capim citronela no controle de ervas daninhas

Abstract

Allelopathy can be an important tool in the sustainable management of weeds, with the use of allelopathic species directly in agricultural areas or with the application of products derived from these species. In this sense, this project aimed to evaluate the allelopathic effect of aqueous extract and citronella (Cymbopogon nardus) essential oil applied to seedlings of sourgrass (Digitaria insularis) and beggartick (Bidens pilosa). Two tests will be conducted, one using aqueous extract and the other using essential oil from the donor species. The experimental design will be completely randomized with four replications. The experiments will be allocated in a 2x4x2 factorial scheme, the first factor will be composed of the allelopathic species (citronella), the second by the doses of the compounds (0, 1, 3 and 6% of the essential oil or 0, 10, 30, 60% for the aqueous extract) and the third factor will be composed of the target species (sourgrass and beggartick). The target species will be grown on substrate in growth chambers, the compounds will be applied when the seedlings have between two to three developed leaves, with spraying. Seedling mortality, phytotoxicity, height and dry mass will be evaluated seven days after application. Both aqueous extracts and essential oils from both donor species are expected to cause control of target species.