Oklahoma Watermelon Anthracnose Model

Model Description
Site-Specific Interactive Model
Current Output
Seasonal Output
Related Links
NOTE: The current version of the Oklahoma Watermelon Anthracnose Model is experimental, but is being made available for evaluation purposes. Output of the current model should be interpreted strictly as a rough guide for scheduling fungicide applications. Additional research is underway to further refine the model to improve its performance under real-world conditions.

The Oklahoma Watermelon Anthracnose Model is a weather-based management tool which can be used to schedule fungicide applications for watermelon anthracnose . It was developed by Oklahoma State University (OSU) plant pathologists and based on field studies conducted at a number of sites in Oklahoma during 1992-1997. The Model is based on the accumulation of "infection hours", periods during which temperature and humidity conditions are favorable for disease development. Using weather data from a nearby Oklahoma Mesonet station, the Model calculates the number of infection hours which have occurred since the date of the last fungicide application, if it has occurred, or since the first flowering date of the the male watermelon flowers. If the number equals or exceeds 80 hours, the Model recommends a fungicide application.

The Oklahoma Watermelon Anthracnose Model operates from May 1 through October 31. It is updated daily around 6 a.m. CDT so that the latest results should be available by 6:30 a.m. each day.

All customers are strongly urged to read the Model Description for a greater understanding of the Model and for further instructions on how to utilize the spray advisory. To utilize the Model, please go to the Site-Specific Interactive Model section and follow the instructions. You will need to enter either the date (if available yet) of first flowering of male watermelon flowers or the date (if available) of your last fungicide application.


As with any pest management model, the Oklahoma Watermelon Anthracnose Model is to be regarded as only a tool in making fungicide application decisions. It is not intended to replace the best judgment of the grower in making such decisions.

Address questions about the Oklahoma Watermelon Anthracnose Model to Dr. Jim Duthie at jduthie@okstate.edu