According to The South Carolina Grower, fusarium wilt disease is becoming more widespread in watermelon fields in South Carolina. Clemson Plant Pathologist Tony Keinath said fusarium wilt symptoms include wilting of leaves at the crown of the plant, wilting of one vine on a plant or wilting without yellowing of a small plant.
The Fusarium fungus is most active when the soil temperature is below 81 degrees Fahrenheit. Although daytime temperatures were warm in April, the nights were still cool enough to allow infections to occur.
There is nothing that can be done now to manage Fusarium wilt. All successful management practices must be done before transplanting begins.