Gray Mold Resistance

Gray mold resistance refers to a plant's genetic capacity to resist or tolerate Botrytis cinerea, a fungal pathogen commonly affecting cannabis in humid or high-moisture environments. This trait is polygenic, meaning multiple genes contribute to resistance levels, and expression varies based on cultivation conditions, humidity, and air circulation. Breeders working in this category often select parent plants showing reduced susceptibility to botrytis infection, particularly in dense floral structures where moisture accumulation is highest. Gray mold resistance is not immunity but rather a reduced tendency to develop visible infection or rapid fungal colonization. This trait is increasingly documented in breeding programs focused on outdoor and greenhouse cultivation stability. Understanding botrytis pressure in specific growing regions helps breeders prioritize this genetic line.

Breeders incorporate gray mold resistance through multi-generational selection of parent plants showing delayed or minimal botrytis symptoms under controlled high-humidity stress testing. This trait is especially valued in lines intended for humid climates or outdoor cultivation where environmental control is limited, as it reduces crop loss risk and improves overall plant vigor under disease pres