VINASSES AND SOIL-BORNE FUNGI

Abstract

     The purpose of this research was to study the biocidal effect of three agroindustrial subproducts, concretely sugar beet, sugar cane and wine vinasse. Two tests were carried out. The first centred on studying the action of the three agroindustrial subproducts in vitro. In dilutions at initial doses of 1%, 3% and 5%, their performance against six phytopathogenic fungi was analyzed: Fusarium oxysporum f.sp. melonis race 0 and 1, F. oxysporum f.sp. radicis-cucumerinum, Sclerotinia sclerotiorum, Pythium aphanidermatum and Phytophthora parasitica. Next, the antagonistic capacity of the solutions assayed in vitro was tested in soil, studying the incidence of the subproducts on the Fusarium populations in these soils.      Results from in vitro testing determined that wine vinasse is what shows a 100% capacity to suppress fungal growth with concentrations that are not very high, between 5% and 7% for Fusarium oxysporum f.sp. melonis race 0 and 1, S. sclerotiorum, P. aphanidermatum and P. parasitica and 10-15% for Fusarium oxysporum f.sp. radicis-cucumerinum. On the other hand, sugar cane vinasse produced an increase at high concentrations and sugar beet vinasse showed an approximate 100% suppressor effect on fungal growth for only some of the phytopathogens tested: S. sclerotiorum (15%), P. aphanidermatum (7%), P. parasitica (15%) and Fusarium oxysporum f.sp. radiciscucumerinum (15%).      In the soil samples analyzed none of the three vinasse extracts decreased fusaric microbiota, producing an increase in the three samples tested. This would implicitly convey an improvement in soil quality by producing a potential increase in bacterial and fungal microbiota.