Ação bioherbicida de óleo essencial de rizoma de gengibre na germinação de nabo e azevém

Abstract

The damage caused by weed infestation has been one of the biggest limitations for crop productivity. Currently the most used control method is chemical control, but this method has some negative impacts. Thus, less harmful solutions have been sought, such as the use of natural essential oils. In this sense, the aim of this study was to evaluate the bioherbicidal action of the essential oil of ginger rhizome (Zingiber officinale) in the germination and development of ryegrass (Lolium multiflorum) and turnip seedlings (Raphanus sp.). The experiments were conducted in the laboratory. The essential oil was extracted from fresh rhizomes using the hydrodistillation process. The experimental design used was completely randomized with three replications. The experiments were allocated in a 4x3 factorial scheme, the first factor consisting of doses of essential oil (0, 5, 10, 25 ml L-1 ) and the second factor by formulations (0 + 0 10 + 0 and 10 + 10 ml L-1 emulsifier + surfactant). The variables analyzed were: germination speed index (IVG), seedling dry mass, length of shoot and root system and percentage of normal and abnormal seedlings. The essential oil of ginger negatively influenced the germination and growth of seedlings of the turnip, showing more effective control as the dose increased. In ryegrass it was possible to observe 100% control of germination and other variables regardless of the dose used. The formulation improved the behavior of the essential oil, especially when used emulsifier and surfactant in combination. The essential oil of ginger has a bioherbicidal effect on the germination and growth of turnip and ryegrass seedlings, enhancing the effects with emulsifiers + surfactants in its formulation.