Resumo

FRANCISCO-FRANCISCO, Nazario et al. Immobilization of Trichoderma harzianum on chitosan hydrogels and its use in tomato (Solanum lycopersicum). Terra Latinoam [online]. 2012, vol.30, n.1, pp.47-57. ISSN 2395-8030.

The immobilization of Trichoderma harzianum on chitosan hydrogels and their effects on greenhouse tomato plants (Solanum lycopersicum) was documented. The experiment was conducted in two cycles. In July-August 2009 and March-April 2010. This consisted in the germination of tomato seeds in pots with turb as substrate. Six treatments were established: two treatments of T. harzianum immobilized on chitosan hydrogels applied to two doses (6 and 3 g kg-1 of substrate), two treatments with chitosan hydrogels applied to the same doses without the fungus, a treatment where the fungus was applied to the substrate as a suspension, and a control (only substrate). In both cycles the viability of T. harzianum in the substrate samples used for treatments, at the time of immobilization and 30 and 51 days after sowing was tested. The results show that the growth of fungi immobilized in the first cycle was similar in all treatments, in the second cycle, when the high concentration of T. harzianum (Th) was maintained for a longer time, the superiority of the immobilized fungus was evident. In terms of effects on tomato plants of the variables studied, we observed that treatments with the fungus immobilized in the hydrogels produced less plant growth and plant biomass, but the P, Ca, and Cu mineral content was higher in treatments with the presence of fungus. There was no effect on the leaf epidermis, vascular tissue of leaves, stems and roots, or CO2 assimilation (P ≤ 0.05).

Palavras-chave : biopolymers; biological control.