Fusarium spp. update September 2015
BIOCOMES partner BIOGARD has investigated in the first half of 2015 the possibilities of a liquid, oil-based formulation for a commercial seed treatment of maize and other cereals based on the Trichoderma harzianum strain DSM25764. Tests with the oil-based formulation with several co-formulants, showed a reduction in the germination rate of the maize cultivars. Therefore, the BIOCOMES partners will focus in the next two years on the development of a wettable powder formulation for the control of Fusarium spp in maize.
Wettable powder formulation
To avoid further germination problems, further studies are focused on a wettable powder formulation. This formulation proved to be adequate for seed treatment of maize and showed an acceptable shelf life. In future field studies this wettable formulation will be used to evaluate the efficacy of the Trichoderma harzianum strain against plant pathogens.
In order to obtain the best performance from the BCA to be developed, its behaviour in presence of different and critical temperatures, different pH values and different water activity has been investigated. The optimal conditions for fungal growth were warm temperatures, sub-acidic pH and high water activity. The fungal growth responses were also investigated in the interactions of these three factors.
Fungal response to chemical compounds pesticides
Next to environmental conditions, fungal response to chemical compound used in conventional agricultural practices is an important issue to investigate. Fungicides, insecticides and herbicides as an active ingredient or co-formulant, can affect BCA growth. The investigation of fungal behaviour in the presence of different concentration of pesticides suggested compatible and incompatible relationships with the Trichoderma harzianum strain DSM25764.
The effect of pH
As a further step toward application in the open field, the ability to grow in soil with various pH has been studied. The data obtained revealed a quite similar growth in all tested soils despite the differences in their pH values.