Toxicidade de óleo essencial de laranja em sementes e plântulas de nabo e picão-preto

Abstract

Plant essential oils can cause damage to other plant species, with potential use as bioherbicides in weed management. In this sense, the objective of this study was to evaluate the effect of the essential oil of orange peels on seed germination and seedling growth of turnip (Raphanus sp.) and black billed (Bidens pilosa). The experiments were conducted in the laboratory. The essential oil was extracted from the orange peel using the hydrodistillation process. Trials were conducted to evaluate germination and development of Raphanus sp. and Bidens pilosa subjected to doses of orange essential oil. All trials were conducted in a completely randomized design with five repetitions. The treatments were formed by doses of the essential oil, with 0, 5, 10, 25 and 50 g L 1 of essential oil for the tests. The tests with application in the seeds were carried out in the laboratory, with germination on paper. For the test with application on seedlings, they were grown in pots with substrate, and later the application was carried out in its aerial part. The following were evaluated: germination, germination speed index, mortality, phytotoxicity, the height of the dried mass of Raphanus sp. from Bidens pilosa O oil essential oil negatively influenced the germination and growth of seedlings of Raphanus sp. and Bidens pilosa, showing more effective control at the highest dose tested (50 g L 1). The application of orange essential oil in seedlings reduced the growth and accumulation of dry mass of the plants of Raphanus sp. and Bidens pilosa, showing more effective control at the highest dose tested (50 g L 1). The orange peel essential oil under the conditions tested proved to be a good option for use in bioherbicides, controlling the germination and development of seedlings of the weed species studied.