Substrate evaluation for Trichoderma spore production and rice growth study in TPT03, TPT02, MRT35 and MRT40 antagonist strains

Abstract

In Northwestern Argentina, bean production constitutes a major agricultural activity. One of the most complex phytosanitary problems is caused by Sclerotinia sclerotiorum. The difficulties to the management of this pastogen make the biological control and Trichoderma an interesting alternative for the suppression of the fungus. There are several records which highlight the multiplication of Trichoderma spp. in low-cost substrates originated as industry by-products. In the province of Tucumán, the sugar industry produces large amounts of sugar cane bagasse and molasses. The aim of this work was to evaluate the artisanal production of Trichoderma spores in different substrates by means of solid fermentation and the growth of native antagonist TPT03, TPT02, MRT35 and MRT40 strains in rice. The substrates with the greatest concentration of conidia per gram on the tenth incubation day were the ones grown in rice grains (17,8 x 108 conidia/g) and the one conformed by bagasse moistened in 10% molasses solution (14,4 x 108 conidia/g). The Trichoderma strains evaluated in rice grains showed differences in their growth and sporulation. TPT03 strain (T. afroharzianum) produced the greatest amount of conidia and presented the fastest growth among all the evaluated strains on the tenth incubation day. The results obtained reveal that the production by means of fermentation in a solid substrate is a feasible, rapid and low-cost alternative for obtaining high-quality inoculum of the selected native Trichoderma strains. In addition, the implementation of the substrate based on bagasse and molasses, by-products of the sugar industry in the province, is an alternative to be taken into account due to its low cost, high availability and efficiency in the production of conidia.