New Tool To Predict Anthracnose Risk For Blueberries

Anthracnose fruit rot, caused by the fungus Colletotrichum fioriniae, is one of the major blueberry fruit rot diseases in Michigan. Michigan’s climate is conducive to the development of anthracnose fruit rot making it challenging to control. Anthracnose fruit rot causes in-field losses as well as postharvest losses that affect fruit quality. To aid in management decisions, an anthracnose fruit rot risk prediction model based on these environmental factors has been developed.

Several studies have linked spore dispersal and infection with rainfall events and extended periods (12 or more hours) of leaf wetness, which happens frequently in Michigan.

The University of Florida developed a prediction model for strawberry anthracnose fruit rot based on temperature and leaf wetness duration. This model was adapted to develop a Blueberry Advisory System for blueberry anthracnose fruit rot given the similarities between the two diseases. Researchers at Michigan State University (MSU) have worked with the developers at the University of Florida to extend the Blueberry Advisory System to Michigan.

The Blueberry Advisory System gathers weather data from automated weather stations in the MSU Enviroweather network and calculates the risk level (low, medium or high) using the prediction model. There is also a weather tab to access detailed weather data including temperature, relative humidity, rain, leaf wetness duration, and the average temperature during leaf wetness.

Once blueberry bushes reach bloom if your location is considered medium or high risk, it is recommended to apply fungicides on a seven-to-10-day interval but maintain a 10-to-14-day interval if your location is considered low risk.

The Blueberry Advisory System can be used as an educational tool to inform growers about the weather conditions favorable for anthracnose fruit rot development, as well as aid in making management decisions.

For more about the new anthracnose fruit rot risk prediction model, continue reading at canr.msu.edu.