Azole fungicides are broadly used
- to control mildews and rusts of grains, fruits, vegetables, and ornamentals;
- powdery mildew in cereals, berry fruits, vines, and tomatoes; and
- several other plant pathogenic fungi.
Over one-third of total fungicide sales are azoles (mostly triazoles) and over 99% of the DMIs are used in agriculture. In addition, there are over 25 types of azole DMIs for agricultural uses, far more than the three licensed medical triazoles for the treatment of aspergillosis. Furthermore, the azoles could persist and remain active in many ecological niches such as agricultural soil and aquatic environments for several months.
The widespread application of triazole fungicides and their persistence in the environment are significant selective forces for the emergence and spread of Azole-resistant A. fumigatus (ARAF). These environmental triazoles can reduce the population of azole-susceptible strains and selecting for azole-resistant genotypes. Intensive use of DMI fungicides for post-harvest spoilage crop protection against phytopathogenic molds is known to cause the development of resistance in many fungi of agricultural importance.