Substâncias GRAS no controle do crescimento de Colletotrichum gloeosporioides e Fusarium guttiforme in vitro

Abstract

Colletotrichum gloeosporioides and Fusarium guttiforme are phytopathogenic fungi causing various post-harvest diseases in fruits. Substances GRAS - (Generally Regarded Ase Safe), they are an alternative for the control of microorganisms in the post-harvest phase, due to their fungistatic and fungicide effects. The objective of this study was to evaluate the inhibitory effects of five GRAS substances over the growth of pathogenic fungi C. gloeosporioides and F. guttiforme in vitro. Culture media (PDA) were supplemented with 1%, 3% and 5% sodium bicarbonate, sodium carbonate, calcium carbonate, calcium chloride and 0.1% 0.5% 1% potassium chloride. 10?l spore solution was inoculated at a concentration of 5x103ml/spore. From the five substances used in the tests, sodium bicarbonate and sodium carbonate inhibited 100% of C. gloeosporioides growth, the others were not limiting to the development of the fungus when compared to control. Sodium carbonate inhibited 100% of F. guttiforme growth at all concentrations. Were also positive, sodium bicarbonate in concentrations of 3% and 5%. The treatment with 5% calcium chloride at 51% reduced the growth this phytopatogen. Other substances not reduced or inhibited the mycelial growth of the pathogen when compared to the control. From the five substances GRAS tested in this work, sodium carbonate and sodium bicarbonate, were effective in inhibiting the mycelial growth of C. gloeosporioides. Sodium carbonate, sodium bicarbonate and calcium chloride were able in to reduce the growth of F. guttiforme