Óleos essenciais e extratos vegetais no controle de Monilinia fructicola in vitro e da podridão parda na pós-colheita de pêssegos

Abstract

Alternative products for disease control aim to replace chemicals, providing fruits with the same quality, without harming health and the environment. The objective of this work was to evaluate the potential of essential oils and hydroalcoholic extracts (70% alcohol) and hot and cold aqueous plant extracts of rosemary (Rosmarinus officinalisL.), garlic (Allium sativum), cloves (Sizygium aromaticumL.), wormwood (Artemisia absinthium), oregano (Origanum vulgareL.) and Surinam cherry (Eugenia uniflora) in the in vitro control by direct and indirect contact of the fungus Monilinia fructicolaand in the Dourado peach variety post-harvest. Two studies were carried out. In Study I, essential oils and plant extractswere evaluated by direct and indirect contact, analyzing mycelial growth, mycelial growth index, inhibition of mycelial growth, minimum inhibitory concentration, minimum fungicidal concentration, phytoalexin induction, toxicology of products in Artemia salineand scanning electron microscopy. In Study II, plant extracts and essential oils were evaluated by indirect and direct contact in post-harvest peaches, analyzing the incidence and severity of brown rot in fruits, in addition to resistance induction, with analysis of the enzymes phenylalanine ammonia lyase, chitinase and -1,3-glucanase. The experimental design was completely randomized, with the concentration used for essential oils 1% and plant extracts 10%. In Study I direct and indirect contact withessential oils of garlic, cloves and oregano; direct contact of the cold garlic extract; hot extract of rosemary, garlic and cloves; hydroalcoholic extract of garlic and cloves obtained the best results regarding the evaluations performed. In Study II, the essential oils of garlic by indirect contact and oregano by direct contact had the potential to control the incidence and severity of brown rot in the post-harvest of peaches. These oils also induced resistance by activating the enzymes FAL and chitinase. Thus, clove and oregano essential oils obtained satisfactory results in Studies I and II and are promising for further studies in the control of M. fructicola.