Powdery Mildew Resistance

Powdery mildew resistance refers to a plant's genetic capacity to resist or tolerate infection from powdery mildew fungi, commonly Erysiphales species. This trait is determined by multiple genes and environmental factors, making it a complex polygenic characteristic rather than a single-gene resistance. In cannabis breeding, lines exhibiting reduced susceptibility to powdery mildew are increasingly valued by cultivators working in humid or challenging climates. Resistance is often assessed through controlled inoculation trials and field observation over multiple generations. Breeders working toward mildew-resistant cultivars typically cross tolerant parents and select offspring showing slower disease progression or lower fungal load. This classification has become more prominent as growers seek to reduce fungicide inputs.

Breeders incorporate powdery mildew resistance through multi-generational selection and backcrossing programs, identifying resilient germplasm within heritage or regional landraces. Resistance lines are crossed into elite genetics to combine desirable traits with disease tolerance, though phenotypic expression can vary across environments and cultivation methods.