The deployment of varieties resistant to downy mildew and powdery mildew is a promising innovation enabling significant reductions in treatment frequency indices (IFT) (Oscar, 2023).
A key challenge in their deployment lies in managing the durability of resistance. Indeed, just as antibiotic use promotes the selection of resistant bacteria, cultivating resistant varieties promotes the selection of pathogens able to overcome resistance genes, especially when these varieties are widely grown.
Moreover, intensified production systems and monocultures make agricultural systems more vulnerable to the breakdown of varietal resistances. Once adapted to a new resistant variety, a pathogen finds a large area of identical plants in which to spread rapidly.
Resistance genes are not eternal! To learn more about deployment strategies: