Influence of the medium on production of trichoderma agent for biocontrol of maize fungal diseases

Maize is important agricultural crop that is susceptible to infections by various phytopathogenic fungi. Maize grain as a rich source of nutrients represents a very good medium for the development of toxic fungi from the different genera. Synthetic fungicides are generally used to protect plants from various pathogenic fungi. However, this practice increases the risk of fungicide resistance and environmental degradation of agroecosystems. The use of Trichoderma isolates in biological control is an alternative strategy, particularly for the problems of resistance and environmental pollution, thus improving the economic and biological sustainability of agroecosystems. In this paper, the effect of medium composition on the production of Trichoderma harzianum biocontrol agent effective against maize pathogens, Helminthosporium carbonum and Penicillium sp., was examined. Results of Scheffe multiple range test showed that the best medium for production of T. harzianum bioagent effective against H. carbonum and Penicillium sp. contains soluble starch as carbon source and soybean meal as nitrogen source. By applying this medium formulation, maximal inhibition zone diameters of 54.33 mm and 24.67 mm was registered in vitro for H. carbonum and Penicillium sp., respectively. Production of Trichoderma bioagent was further tested on the selected medium in a ten times larger volume, Woulff bottle, in which the success of this bioprocess was confirmed. The results obtained in an increased volume on a selected medium showed that this bioprocess can be shortened to 84 h, which contributes to the economy of the bioprocess.