Development and validation of IPM strategies for the cultivation of cisgenically modified late blight resistant potato

Abstract Potato late blight disease remains the primary stressor of commercial potato production across the EU, typically requiring >10 fungicide applications per growing season to offset crop losses. In response, the goal of this study was to test and validate a novel, more durable, control strategy for potato late blight. This IPM2.0 strategy is based on the principles of Integrated Pest Management (IPM) which sees the deployment of a late blight resistant potato genotype, a cisgenically modified, Desiree based resistant potato line here, in conjunction with pathogen population monitoring for virulence to the resistance genes (R genes) deployed and a “do not spray unless”, low input fungicide spray strategy. Field evaluations were completed in the Netherlands and in Ireland in 2013, 2014 and in Ireland in 2015. Comparators used in this study included the original but susceptible potato variety Desiree and the conventional but highly resistant variety Sarpo Mira. The novel IPM2.0 strategy was compared to local common practice (fungicide applications on a near weekly basis) and an untreated control. Overall, the IPM2.0 control strategy validated here reduced the average fungicide input by 80–90% without compromising control efficacy. Corresponding environmental side-effects were reduced proportionally. The results underline the pragmatic role host resistance can provide to commercial potato production systems and to society at large if employed as part of an integrated late blight control system.