Fungus Toxicity of Baccharis dracunculifolia (DC.) Essential Oil on Colletotrichum gloeosporioides (PENZ.)

Abstract

Anthracnose caused by the phytopathogen Colletotrichum gloeosporioides causes heavy economic liabilities in tropical fruit plants such as the avocado Persea americana Miller. The pathogen generally attacks the fruit. Current analysis evaluated the fungus toxicity of the essential oil of Baccharis dracunculifolia on the phytogen C. gloeosporioides obtained from the avocado with symptom of anthracnose. Fresh leaves of B. dracunculifolia were harvested in the campus of the Universidade Paranaense for the extraction of essential oil by hydro-distillation. It was stored in an amber flask and kept at 8ºC. The fungus C. gloeosporioides was obtained from contaminated fruits. Isolation occurred in medium BDA till cultures became monosporic. The medium BDA was spread on petri plates for the biological assay at aliquots 5µL, 20µL, 35µL, 50µL, 65µL and 80µL and on the medium with a Drigalski spatula. A 7mm² area with fungus mycelium was added to the plate center. Design was totally randomized with three repetitions. Although inhibition occurred in all concentration, mycelium growth index of concentration 80µL was lower, with higher inhibition. This index is statistically equal to relative control (fungicide) respectively with means 2.761mm and 2.525mm.