Editor: Cesar Escalante                                                                                               

Extension Plant Pathologist

escalac@purdue.edu

812-886-0198

August 01, 2026

MELCAST fungicide recommendations continue to indicate 14-day spray intervals across most Indiana locations for both cantaloupe and watermelon production areas. Fields in the Wanatah area are currently recommended to follow 11-day spray intervals for both cantaloupe and watermelon production.

Gummy stem blight and anthracnose have continued to be observed in several fields over the past two weeks. Growers should continue scouting regularly and maintain effective fungicide programs using both preventive and curative products, selecting fungicides based on their efficacy against the diseases present in each field. Where symptoms are actively developing, prioritize fungicides with strong curative activity and rotate among different FRAC groups to reduce the risk of fungicide resistance.

Last week, downy mildew was reported on cucumbers in northern Indiana. This observation serves as an alert for all cucurbit growers to intensify scouting efforts for symptoms of this disease. Although downy mildew has not been confirmed on watermelon or cantaloupe at this time, growers should remain vigilant and consider preventive fungicide applications where conditions favor disease development. In addition, growers should continue preventive management programs for Phytophthora blight, especially in fields with poor drainage or areas prone to water accumulation following rainfall.

I hope you are having a successful harvest season.

If you have any questions or comments, please feel free to contact me.