Efeitos da simulação da solarização do solo com materiais vegetais sobre o crescimento micelial de fungos fitopatogênicos habitantes do solo

Abstract

The incorporation of plant materials associated with soil solarization has been a promising progress to control soilborne phytopathogenic fungi. The aim of this study was to evaluate certain effects of incorporation and decomposition of broccolis, castor bean, wild and sweet cassava, in the soil, under microcosm conditions maintained in BOD (37±2°C), on the mycelium of Fusarium oxysporum f. sp. lycopersici race 2, Macrophomina phaseolina, Rhizoctonia solani AG-4 HGI and Sclerotium rolfsii. Thus, four identical experiments were established with five treatments of four different and independent periods (7, 14, 21 and 28 days). The assessed parameter was the innocuous, fungistatic and fungicide effects of the treatments on the mycelium of fungi. Fungistatic and fungicide effect was verified for the mycelium of F. oxysporum f. sp. lycopersici race 2, R. solani AG-4 HGI and S. rolfsii. Fungi with fungistatic effect presented lower velocity of mycelial growth compared to the general control, which consisted of incubation of the fungi at a temperature of 25±2°C. Fungicide effect occurred at 21 days of incubation for F. oxysporum and R. solani and at 28 days for S. rolfsii. Only innocuous effect was observed for M. phaseolina. The factor that caused fungistatic and fungicide effect on the mycelium of fungi was the association of the temperature of 37±2°C with the period of the treatments. That association also interfered in the mycelial growth velocity of the fungi that showed fungistatic effect.