Guess the Pest! Week 6 Answer: Peach Leaf Curl

David Owens, Extension Entomologist,

Congratulations to Jim Bennett for correctly identifying last week’s challenge as peach leaf curl. Jim and others who correctly identified the problem on my peach tree will be entered into the end of season award. I also apologize for not updating the google form last week.

yellowed and curled leaves on a peach tree

peach with yellowed and curled leaves

Someone once told me that peaches are born with a death wish. It seems like they get a special host of insect and disease problems, including peach leaf curl. This is a fungal infection of the bud. Cool weather allows the fungus to complete its life cycle and continue spreading on the leaves. Infected leaves will eventually drop off, resulting in partial defoliation. The time to treat was before bud break when rain washes overwintering spores from the bark onto the swelling buds. Warm weather, above 80, basically shuts down the fungus, which is probably why I did not see this on my peach trees last year. Interestingly, of my three trees, only one has this, although I will be treating all three next year. Penn State has an excellent fact sheet regarding this disease here: Alas, it has not been that warm, time for me to harshly thin my little tree.