Abstract
<jats:p>Potato is a key staple crop, and late blight caused by the oomycete Phytophthora infestans remains the most damaging potato disease, threatening food security and sustainable production. Host resistance and fungicides are central for disease management, but P. infestans can rapidly overcome cultivar resistance and develop insensitivity to active ingredients in synthetic fungicides, making induced resistance (IR) an attractive complementary strategy that mobilises plant defences and may offer more durable, environmentally sound control. This work addresses critical knowledge gaps that currently limit IR in integrated pest management by quantifying the growth and yield costs of IR, assessing how elevated CO2 (eCO2) modifies induced resistance to late blight, and evaluating hyperspectral imaging for early disease detection in the field. Across experiments, resistance inducers and genetic resistance revealed measurable context dependent costs.: For example, high throughput phenotyping indicated that β aminobutyric acid (BABA) and stacking Resistance (R) genes in potato lines incurred detectable allocation costs, expressed as subtle penalties on growth and, in some cases, yield, whereas potassium phosphite (KPhi) and single R-genes showed little or no consistent allocation cost under the same conditions. Under eCO2, photosynthesis and tuber production increased and overall susceptibility to late blight changed little, while BABA IR against P. infestans remained strongly cultivar , isolate and CO2 dependent, yet consistently triggered a broadened defence related molecular signature. In parallel, hyperspectral imaging coupled with deep learning detected subtle canopy reflectance changes before visible symptoms and enabled in field classification of the asymptomatic biotrophic phase of late blight across multiple genotypes. Together, the results indicate that carefully selected IR treatments, combined with such imaging based monitoring, can support climate smart, integrated strategies for managing potato late blight.</jats:p>