MELCAST Update

(www.melcast.info)

Editor: Cesar Escalante                                                                                             June 11, 2026

Extension Plant Pathologist

escalac@purdue.edu

812-886-0198

In some areas of Indiana, recent rainfall events may increase the Environmental Favorability Index (EFI). As a result, fungicide sprays for watermelon and cantaloupe may need to be applied more frequently in certain locations.

For cantaloupe, data from June 4 through June 10 suggest maintaining a 14-day spray interval across all locations. For watermelon, MELCAST data show a similar trend, except in West Lafayette and Wanatah, where current conditions indicate spray intervals of 11 and 12 days, respectively, as of today.

As a reminder, be sure to record the date of each spray application and track the cumulative EFI values to determine when the next application is needed. The EFI thresholds are 20 for cantaloupe and 35 for watermelon. Adjust the timing of applications accordingly based on when the last fungicide was applied.

Continue to monitor for other common diseases, such as bacterial diseases and Phytophthora. The MELCAST system does not account for these diseases, so pesticide applications should be made promptly if any of these issues are observed in your fields.

If you have any questions, please feel free to reach out.

Sincerely,
Cesar Escalante
Extension Plant Pathologist