if we use any specific micronutrient in excessive amount in broth medium to grow bio-control fungi, so is it possible that thus specific micronutrient affect the secondary metabolites production by the particular bio-control fungi ?
Depends on which micronutrient you are increasing and by how much. Most micronutrients show deficiency and toxicity responses in a dose dependent manner. It also depends on the metabolic pathways being used to synthesize the secondary metabolites. You need to ask yourself is this micronutrient an inhibitor or activator for each enzyme in the synthesis pathway or is it a cofactor involved in the synthesis of an intermediate.