Potato fungicide resistance avoidance strategies

Fungicides are integral to the fight against late blight in potatoes as the currently planted varieties are susceptible to the disease. Fungicide use is necessary, even for resistant varieties, to protect R-genes. Thus, the use of fungicides will remain key to controlling late blight. However, P. infestans can rapidly evolve to defeat the active ingredients in fungicides. The emergence of novel P. infestans genotypes (e.g., EU43, EU37) with reduced sensitivity to notable fungicides restrains our ability to manage the disease effectively and sustainably. Therefore, it is necessary to understand the development of fungicide resistance and develop suitable mitigation strategies. So, the project aims to understand the sensitivity of P. infestans populations to the fungicides used in Denmark, design markers to monitor fungicide resistance, understand the drivers of fungicide resistance development, and devise suitable anti-resistance strategies to mitigate them. Towards this goal, we will study the sensitivity of P. infestans to key fungicides in DK and ascertain other traits that enable the establishment of fungicide-resistant strains (WP1); develop and validate markers for mutations responsible for resistance to mandipropamid (WP2); identify the drivers (e.g., dosage) for the development of fungicide resistance and develop anti-resistance strategies to mitigate fungicide resistance (WP3); establish and implement a long-term fungicide resistance monitoring plan with stakeholders in the potato industry to ensure the continuous monitoring and early detection of fungicide resistance to the existing fungicides for controlling late blight (WP4). The project will contribute to the sustainable management of fungicides.