Bioformulación de Trichoderma harzianum en sustrato sólido y efectos de su aplicación sobre plantas de pimiento

Abstract

For the use of biofertilizers for horticultural farmers the formulation has to be economical, of easy application and
has to guarantee the efficiency of the inoculum. Our objective was to select a substrate for device Trichoderma
harzianum Rifai and evaluate its effect on pepper (Capsicum annum L.) plants. The development of fungal
biomass and sporulation was evaluated on 4 organic supports: rice, wheat bran, peat, wheat bran + peat (1:1 v/v),
which were separately inoculated with T. harzianum (1 mL 1 x 108 conidia / 1250 cm3 incubated at 25°C). The
mixture of bran+peat showed the highest fungal colonization and sporulation 5 days after inoculation (DAI). The
best viability preservation of conidia of the bioformulate was maintained between 4ºC and 25ºC during 15 DAI,
while at 35ºC and 40ºC the viability was significantly reduced (80%). The highest formation of chlamydospores
was determined at 4°C (76% at 35% DAI), with a reduction towards of about 40-50% at 25°C and 35°C. Four
strains were bioformulated in the bran+peat support and all increased pepper plant growth at 45 DAI. The FCCT
16 strain increased aerial development and photosynthetic capacity by more than 100%. The strains FCCT 199-2
and FCCT 363-2 favored mainly root development. It is suggested as a promising and economic vehicle, the
formulation of strains of Trichoderma in the bran+peat support, whose activity and properties can be maintained
through the formation of chlamydospores in a range of temperatures and conservation time commonly used
among horticultural farmers.