The state of Tocantins has been standing out in Brazil as a big soybean producer. However, there are many factors that contribute for the reduction of soybean productivity; the main ones are: losses due to diseases and decrease of planting booth. The utilization of biological control constitutes an interesting and important strategy to enable the reduction or substitution of the use of pesticides. Fungi such as Trichoderma and Purpureocillium are important antagonists, in soil, against root diseases and phytopathogenic nematodes. Several products based on Trichoderma and Purpureocillium are worldwide commercialized. Thus, this study aimed to evaluate the effects of the inoculation of Trichoderma and Purpureocillium on soybean crop at different regions (Gurupi, Porto Nacional, Alvorada and Crixás) in Tocantins. The experiments were performed under field conditions at different cities, which produce soybean in Tocantins, using the products TrichoPlus and TrichoMix formulated based on Trichoderma (Trichoderma asperellum UFT 201) and Purpureocillium lilacinum at different dosages, aiming biocontrol for booth maintenance, and thus, also aiming increase in productivity. The inoculation of Trichoderma and Purpureocillium present in the products TrichoPlus and TrichoMix influenced positively the booth maintenance, soybean productivity and helped the growth promotion at all places assessed. In Gurupi, in experiments I and II, not only the isolated application of Trichoderma (TrichoPlus) but also the joint application of Trichoderma and Purpureocillium (TrichoMix) promoted increases in booth maintenance and higher productivity values in relation to other treatments. In Porto Nacional, the inoculation of products TrichoPlus and TrichoMix influenced positively the booth maintenance and productivity of precocious, intermediate and late soybean cultivars. In Alvorada, the inoculation of Trichoderma (Trichoplus) in soybean of first and second year increased the survival index of plants, but did not affect significantly the productivity. In Crixás, the inoculation of Trichoderma (Trichoplus) promoted increases in booth maintenance and also higher productivity values. The use of microorganisms as biocontrol agents of plant diseases, despite being more studied lately, still need to be better comprehended, in order to achieve its optimal efficiency.
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