Cherry Powdery Mildew

Cherry powdery mildew is a surface fungus that manifests itself on both the developing leaves and fruit of cherry trees. Cherry powdery mildew appears as areas of white fungal growth, often in circular shapes. Presence of powdery mildew on cherries not only damages the fruit on which it grows, but can quickly lead to contamination of entire boxes of packaged cherries at harvest, where fruit infected with powdery mildew begin to rot and quickly spread to neighbouring fruit in the box or bin. 

 

Cherry powdery mildew overwinters as ascospores on leaf tissue or in crotches in the tree limbs. Under wet conditions, these spores can be released into the orchard environment and settle on new and developing leaf tissue. Due to its powdery nature, cherry powdery mildew can often be overlooked when fruit is processed at the packinghouse, as when the fruit is washed and cooled the surface layer of the disinctive white fungus appears to have washed away. This however does not remove the fungus from the fruit itself, and once packaged the mildew spores will re-establish on the fruit surface and proliferate inside packed fruit boxes. 

 

The BC Das system allows growers to be informed about the current risk of cherry powdery mildew in the growers' specific geographic location. Using information on temperature and wetness events, the BC DAS system provides the grower with up to date information regarding potential risks for cherry powdery mildew, and timings for protection action. In order for the BC DAS system to be most accurate, the grower must monitor conditions in their own orchard in order to be fully informed about Cherry powdery mildew risk throughout the growing season and avoid loss.

 

The DAS Spray Guide offers different spray options, rates and timings, allowing growers to plan their sprays for coverage, as well as allowing the grower to select for product options currently registered for both conventional and organic use. By following along on the BC DAS model, the grower will have timely information and knowledge of the tools currently available to protect against Cherry powdery mildew in their orchard.  

 

Still interested in finding out more? Check out our BC DAS Cherry powdery mildew model video on YouTube to connect horticultural knowledge from the field with the online DAS program: