Controle alternativo de penicillium expansum em pós-colheita de maçãs

Abstract

Many diseases cause losses in apple fruit, Penicillium expansum blue mold, is responsible for very losses in stored fruit. Alternatives have been studed and used to control plant diseases in order to meet the needs of producers and consumers in the desire to reduce the use of pesticides. Seeking alternativa measures to conventional treatments, we evaluated the effect in vitro and in vivo aqueous crude extract (EBA) of garli (Allium sativum), citronella (Cymbopogon Nardus Rendl.) and eucalyptus (Corymbia citriodora) about the diseaser. The experiment was conduceted at the Federal University of the South Border, Campus South Orange, Paraná, Brazil.In Perri dishes, the mycelial growth was evaluated, using the extracts concentration of 20%. As a control, we used Rovral fungicide (with the active ingredient Iprodione) and was used as witness plates containing PDA medium without adding extacts. The plates with inoculate media wit a 5 mm disc containing the fungal isolate (Penicillium expansum) and kept in the incubator chamber at a temperature of 25+- 2ºC for a period of 16 days. In vivo treatments were teste the curative effect and the protective effect. For made dressings, fruit received two equidistant injuires in the equatorial region with the aid of a standard needle of 1 mm in diameter and 5 mm in length and inoculated immediately after with a solution containing 1x105 spores of the fungus Penicillium expansum, and after 24 hours, submerged for 3 minutes in the treatments. For the protective effect, fruits were first emerged in the extracts and then inoculated. They evaluated the severity and incidence of fruit decay caused by Penicillium expansum by daily measurements of hte diameter of hte lesion for 8 days, at a temperature of 18+-2ºC. In all experiments, the design was completely randomized with five replications. The crude aqueous extract of Corymbia citriodora, Allium stivum had no effect on the growth of mycelium, these values being 57.45% and 27.48% inhibition of colony growth. The use of plant extracts did no affect the fruit quality attributes. The effect of the erbal extract on Penicillium expansum can be attributed to the presence of its metabolites secondary components that may represent an important alternative for the alternative control of disease in fruit.