Although synthetic chemical fungicides provide undoubted advantages in terms of plant protection, their overuse and/or misuse may raise several safety concerns for the environment and human health. Microbial biofungicides, where the active substance is commonly a bacterial or fungal microorganism, are the most promising tools to substitute synthetic chemical active substance used to control fungal diseases. The mechanisms of action of microbial biocontrol agents contained in biofungicides have been classified into four groups (direct antibiosis, competition for space and nutrients, induction of resistance and hyperparasitism). The main advantages of using biopesticides are: they do not leave residues and can be applied close to harvest, they are biodegradable, renewable, safe for workers and can be used in strategies to prevent pathogen resistance. On the other hand, they have a few limitations: low persistency, often a slower effect, and an expiry date. In addition, biopesticides require care in the application and storage and their cost is generally higher than synthetic chemicals. Although they are promising tools, more efforts and resources should be put in identifying and developing a second generation of more performant microbial biofungicides overcoming their major limiting factors.
Keywords: integrated pest management, biopesticides, pesticides, organic agriculture