Bioprospecção de isolados de Trichoderma spp tolerantes a radiação solar e a fungicidas para controle de fungos fitopatógenos

Abstract

The expansion of crops such as soybean, corn and rice stand out in this national scenario, mainly in the State of Tocantins. However, diseases caused by phytopathogenic fungi such as: Sclerotinia sclerotiorum, Fusarium sp., Rhizoctonia solani, Macrophomina and Colletotrichum cause considerable damage to producers. The high cost, abusive use and resistance of these pathogens to the fungicides Fluopyran, Fluazinan, Dicarboximida, Azoxystrobin makes it necessary to search for new forms of alternative control. The use of biological control is a viable and sustainable alternative. The fungus Trichoderma sp. has produced satisfactory results and its large-scale production is a reality in several states of the country. The objectives of this work were: to isolate the Trichoderma spp. Biocontrol potential from phytopathogenic fungi Sclerotinia sclerotiorum, Fusarium sp., Rhizoctonia solani, Macrophomina and Colletotrichum, to evaluate the biocontrol potential of Trichoderma spp. the compatibility of Trichoderma spp. to five fungicidal active principles dicarboximida, fluazinam, fluopyram, axizostrobin and difenoconazole currently used, to evaluate the tolerance of conidia of Trichoderma sp. exposed to solar radiation and to verify the mass production of the fungus Trichoderma sp. on substrates used by biofactories. We found 49 isolates of Trichoderma, molecularly identified 28 isolates of the species T. lixxi, T. harzainum, T. longibrachiatum and T. intractum. All 49 isolates controlled the five phytopathogens, and were compatible with the five active principles of the tested fungicides; in the mass production it was verified that they are plausible of production in the substrates rice and millet and were tolerant to the solar radiation.