Uso de polímeros em formulações para armazenamento de Trichoderma harzianum e Trichoderma viride

Abstract

Trichoderma spp. is one of the most studied funguses as a biocontrol agent, being antagonistic to various plant pathogens in different cultures. This work aimed the production of liquid bio formulate of Trichoderma harzianum and Trichoderma viride based on biopolymer Xanthan Gum (GX) and carboxymethylcellulose (CMC) and the polymer polyvinylpyrrolidone (PVP).The bio formulates were composed of glycerol 10.0 gL -1, yeast extract 0.5 gL -1, MgSO 4 .7 H 2 0 0.2 gL -1, K 2 HPO 4 0.5 gL -1 and NaCl 0.1 gL -1. These amounts were determined by assessing the shortest period of time between the inoculation and sporulation of the fungus in Petri dishes containing PDA culture medium (potato dextrose agar) and bio formulates. The purpose of the use of these products were to make available a formulation that presents 180 days of shelf validity, as regarding the survival parameters (number of spores), evaluated using a Neubauer chamber and infectivity in vitro evaluated by testing direct confrontation with Fusarium oxysporum Schlecht . The evaluations were performed at intervals of 30, 60, 90, 120 and 180 days. The treatments used were G 1 P 1 C 2 (GX, 1.0 gL -1; PVP, 1.0 gL -1; CMC, 2.0 g L -1), G 0.5 P0.5 C1 (GX, 0.5 gL -1; PVP, 0.5 gL -1; CMC, 1.0 g L -1), G 2P 2C (GX, 2.0 gL -1; PVP, 2.0 gL-1) and GPC1 (CMC, 1.0 gL-1), stored in sterile plastic container at room temperature. T. harzianum showed the best result with G 0.5 P0.5C 1 in all periods of assessment. For T. viride none of the treatments was better than the control in the assessed periods. Polymers make possible to develop effective means of storage, extending the life of bio formulates.