Two to three week old fruit seem to be the most susceptible. Mature fruit are covered with a thick wax layer that prevents entry of the bacterium. Fruit that is wounded during the harvest and storage processes can become infected with the bacteria. Control is accomplished by planting disease-free seed. Seed companies test for the presence of the bacterium, but can not guarantee the seed to be bacteria-free.
Work is ongoing to find reliable testing procedures.
Observe seedlings in the greenhouse closely for symptom development and destroy any infected plants. Watermelon cultivars with dark green rind color appear to be less susceptible than light rind colors. However, the observed resistance is not enough to prevent spread of the disease when environmental conditions favor disease development. The incidence of bacterial fruit blotch can be reduced by applications of copper fungicides. Two to three biweekly applications with good foliar coverage is essential for best control.