In western Colorado, home to the treasured Palisade peach, cytospora canker is one of the most economically consequential fungal diseases faced by growers.
A recent survey conducted by Colorado State University in Orchard Mesa found that 100% of the orchards have trees infected with cytospora canker. In some orchards, you can smell the sweetness of gummosis, the sweet oozing of sap from a tree that occurs from injury, stress, pathogen infection or insect damage.
We are part of a team of fruit tree growers, extension personnel and researchers who are developing tools for mitigating cytospora canker in fruit tree orchards in Colorado and Utah.
In a study we published, we estimate this disease results in at least $3 million in annual economic losses for growers in Colorado. In infected large branches, which are called scaffolds, the damage can result in a 50% loss of peaches per tree.
Peaches were first planted in Palisade and Grand Junction in 1882 by one of the first white settlers to the area, John Harlow. Peaches and other fruit trees have been Colorado staples ever since. In 2024, Colorado farmers produced roughly 15,000 tons of peaches valued at $34 million.
