Resíduo de extrato de própolis verde no controle dos fungos Lasiodiplodia theobromae e Colletotrichum gloeosporioides

Abstract

Fungi are responsible for the deterioration of various food products all over the world. Food of plant origin is subject to attack by these organisms while it is still in its development stage, and in many cases pesticides have to be used to control them. However, the use of these products can result in the development of resistance and phytotoxic effects on crops. The use of natural products has therefore become an ecologically viable alternative for controlling these fungi. Among the natural products used for this purpose is propolis, which has shown potential in controlling phytopathogens. The aim of this study was to verify the efficiency of the green propolis extract residue in controlling the fungi Lasiodiplodia theobromae and Colletotrichum gloeosporioides. The study was carried out at the Federal University of the Recôncavo da Bahia - UFRB, in the Microbiology Laboratory located at the Insect Study Center - INSECTA and the Microbiology Laboratory of the Federal University of the Recôncavo da Bahia (UFRB), in two stages: the production of the extract from waste that is normally discarded and the in vitro control tests. The propolis was obtained from producers in the town of Ibertioga-MG (21º 24' 11" S / 43º 57' 15" W). The residue was acquired from the production of propolis extract in the same laboratory. The extract residue was subjected to gas chromatography analysis coupled to mass spectrometry (SHIMADZU brand, model GCMS QP 2010). The compounds were identified using standard spectrum libraries of organic compounds, such as NIST107 and Wiley 229. For the second stage, the mycelial growth of the fungi was assessed in Petri dishes containing Sabouraud culture medium and propolis residue extract. The extracts of the residue were added to the medium at the pre-determined concentrations for propolis (0.5%, 1%, 2%, 4%, 6% and 8%) for the pathogen L. theobromae and (0.5%, 1%, 2%, 4%) for C. gloeosporioides, as well as the control, with 0% concentration and 10% alcohol, all with 5 repetitions. A completely randomized experimental design was used. A fungicide control (Priori®) was also used. The green propolis residue proved to be efficient in controlling the pathogens tested, with the best response for the pathogen C. gloeosporioides with growth inhibition at the highest concentration, and also with promising results for the control of L. theobromae, with a significant reduction in mycelial growth in the Petri dish. The fungicide tested showed no control response, occupying the entire plate along with the control for L. theobromae and for C. gloeosporioides it occupied the plate one day after the control.