Controle da podridão peduncular da manga (Lasiodiplodia theobromae (Pat.) Griffon & Maubl), utilizando extratos vegetais, óleos essenciais e hidroterapia

Abstract

Among the post-harvest diseases of mango (Mangifera. indica L.) stands out stem-end rot caused by Lasiodiplodia theobromae (Pat.) Griffon & Maubl due to high disease severity. For control of stem-end rot are recommended, among other alternatives, preventive spraying with fungicides. However, chemical control alone will not provide protection or curative control culture of L. theobromae. Control of diseases through the use of substitutes to replace the conventional ones, has been researched due to contamination of water, animals , food, soil, and the man himself. Thus, this study aimed to gain control of L. theobromae from mango (cv Tommy Atkins), using essential oils (citronella oil and neem oil), plant extracts (garlic extract, Ecolife ®) and hydrotherapy. Initially, we performed the pathogenicity test, which proved the efficiency of L. theobromae in causing the typical lesions in mango fruits. Then experiments were performed to evaluate the effect of essential oils and plant extracts on the mycelial growth of the pathogen (PIC) at different dosages: 1.0, 1.5, and 2.0% for citronella oil, neem oil and Ecolife ®, 2.5, 5.0 and 7.5% garlic extract, 2.5, 3.5 and 4.5 g / L for fungicide (Mancozeb) and control. All extracts and oils were sterilized with UV light for 30 minutes before being added to the medium after autoclaving. Citronella oil and Ecolife ® at all concentrations inhibited the growth of 100% of L. theobromae in vitro. Neem oil, garlic extract and the fungicide partially inhibited mycelial growth. The products selected in vitro were sprayed on mango fruits (5 ml / fruit), previously wounded and inoculated with disks containing mycelium of L.theobramae (24 hours before). The best performances for the control of the disease were obtained with neem oil (1.0%), citronella oil (1.0%) and Ecolife ® (1.5%), which reduced the severity of the disease. In the second experiment using the hydrothermal treatment, slices were inoculated with the pathogen and 24 hours after inoculation were subjected to temperatures of 53 ° C, 55 ° C and 57 ° C associated with times of 4 'and 5'. The fruits undergoing hydrotherapy did not differ significantly with respect to time and temperature used, no difference between themselves and with the witness. The results showed that citronella oil (1.5%), neem oil (1.0%) and Ecolife ® (1.5%) can be used to reduce the severity of stem-end rot of mango. Hydrotherapy used alone was not effective in reducing the severity of stem-end rot of mango.