Environmental conditions affect biocontrol agents in a field, being appropriate formulations an alternative to overcome this problem. Formulations based on Trichoderma asperellum TV190 were prepared by emulsified mineral or vegetable oils, which protected spores from ultraviolet radiation, showing greater viability of 37-43% (mineral) and 56-63% (vegetable) than the control (8-12%). These formulations improved an antagonism of T. asperellum on Rhizoctonia solani under greenhouse conditions, reducing infected corn seedlings by 72% (mineral) and 59% (vegetable). Necrotic spot size was reduced by 90.04% (mineral) and 87.29% (vegetable). A granular formulation, prepared with degreased corn germ and T. asperellum spores, protected the corn seedlings from R. solani under greenhouse conditions, with 73% reduction of infected plants and 93% reduction of necrotic spot size. Both granular and liquid formulations were able to improve T. asperellum antagonism, suggesting that these formulations could be included in agricultural pest control strategies.

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Paper production generates large quantities of a solid waste known as papermaking sludge (PS), which needs to be handled properly for final disposal. The high amount of this byproduct creates expensive economical costs and induces environmental and ecological risks. Therefore, it is necessary to search uses for PS, in order to reduce the negative environmental impact and to generate a more valuable byproduct. Due to the cellulolytic composition of PS, this work evaluated a solid state fermentation process using it as substrate to obtain spores of the fungus Trichoderma asperellum. Optimal conditions to obtain T. asperellum spores were: 60% water content, 3% (w/w) salts (Nutrisol P® and Nutrisol K®), inoculum concentration at 1x105 spores/g, and pasteurized or sterilized PS. Under these conditions it was possible to obtain 2.37x109 spores/g. T. asperellum spores applied directly to pepper (Capsicum anuum) seeds without PS increased significantly seedling dry mass in greenhouse assays. This work suggests an alternative, economic and abundant substrate for production of T. asperellum spores.

The fungus Trichoderma asperellum has a great potential to be used as biocontrol agent against plant pathogens in field. For this purpose it is necessary to optimize mass production on an industrial scale. This work proposes a method for the recovery and concentration of T. asperellum spores. The addition of the fertilizer Urfos 44®, decreased pH value of spore suspension from 6.31 to 1.76. This condition allowed spores to flocculate in few hours, rendering a more concentrated suspension by a factor of 6 - 7. Spore viability did not significantly decreased in 72 hours under these conditions. These results will contribute to obtain more concentrated products based on T. asperellum using a fast and low cost method.