Fungi of the genus Trichoderma present potential for the control of
phytopathogens and to promote plant growth. Different research cultures prove
this ability and aggregate information about the mechanisms of action of these
bioagentes, however, are still little known mechanisms of action in promoting
growth in the absence of plant pathogens. In addition, the chemical control of plant
diseases is not fully effective, since the pathogen penetrates the vascular tissue of
the plant. Given this, this work had as objectives in three chapters presented,
evaluating the fungitoxicidade of the herbicides Glyphosate and Sulfentrazone on
the mycelial growth and sporulation of Trichoderma isolated from the soil in
Tocantins; determine the effect of inoculation of Trichoderma in papaya seedlings
in the greenhouse and assess spore count and viability of conidia of Trichoderma
in different species using two substrates, rice (Oryza sativa) and pearl millet
(Pennisetum glaucum). The herbicide glyphosate did not affect mycelial radial
growth of the isolates UFT 202 and UFT 204, for other isolated herbicides
promoted a small reduction in the number of spores of Trichoderma. For the
inculação in all the isolates papaya provided plant growth in all the analyzed
variables, with and without natural phosphate, comparing with the witness. The
isolated UFT 201 was superior to the dry mass, the isolated UFT 202 to root dry
mass and MIX to total dry mass with phosphate. Without natural phosphate isolate
MIX was superior to others in all variables. The reviews on substrates after an
incubation period of seven days, note that the isolates UFT 25, UFT 63, UFT 313
and UFT 14 were those who obtained the highest sporulation with averages
ranging from 2.3 x 109 (UFT 14) and 2.7 x 109 (UFT 25) spores g-1 in brown rice
and 3.9 x 109 (UFT 79) spores g-1, in millet. The isolates UFT 313, UFT 14, UFT
37, UFT 79, UFT 201, UFT 205 and UFT 314, demonstrated excellent sporulation
and viability among the substrates, with percentages of 98 to 100% germination of
the conidia mL-1, and 94 to 100% UFT 313, UFT 79, UFT 205, UFT 25, UFT 201
and UFT 37 in millet. For the compatibility test the isolates UFT 25 x UFT14,
UFT25 x UFT313, UFT 63 x UFT37 demonstrated interaction UFT significant by
comparison test by mixed culture between mycelium.
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