ANTIFUNGAL ACTIVITY OF BIOLOGICAL, BOTANICAL AND CHEMICAL PESTICIDES ON THE CAUSAL AGENT OF WILD DISEASES OF TOMATO

Abstract

The vascular wilt of tomato (Solanum lycopersicum L.) is one of the most important diseases that affect production around the world. Biological control has emerged as one of the most promising alternatives to the use of chemical fungicides. The aim of this research was to diagnose the causative agent of the disease and to test the in vitro effectiveness of commercial biological, botanical and chemical compounds against the pathogen. Monosporic isolation of the fungus was performed, the DNA was extracted and amplified from the ITS1 and ITS2 regions of the ribosomal DNA and from the gene fragment of the translation elongation factor (TEF-1α). The sequences were compared with those reported in the NCBI database using BLAST-N software. In Trial I was tested the effectiveness against the pathogen of diffusible metabolites in PDA of the native Trichoderma sp. and T. asperellum, in addition to the commercial T. virens G-41 and T. harzianum. In Test II, the fungitoxicity of chemical and botanical pesticides against the fungus was tested in vitro. Both trials were conducted using a completely randomized design with four repetitions. The ANOVA and the Tukey test (P = 0.05) were performed. The causative agent was identified as Fusarium solani. Trichoderma sp. and T. virens G-41 caused the highest percentage of fungal mycelial growth inhibition, with 77.19 and 77.81%. Zineb, extracts of cinnamon, neem and garlic reduced pathogen growth by 30 to 43.75 %. Comparatively, cooper oxiclorure, captan, carbendazim, mancozeb and benomilo had a 100 % control over F. solani. It is concluded that biological and botanical pesticides act as fungistatics against F. solani and contact fungicides are effective to suppress the growth of the pathogen.