For effective crop control apply fungicide as per recommendation from the Department of Agriculture (plant protection) to control Damping-off, Downey Mildew, Powdery Mildew, and other fungal diseases. Apply recommended insecticide to control sucking pests, fruit flies, and any other insects.
Insecticide spray should not be done at the flowering stage (30 - 50 Days) to enable honeybee activities for pollination.
For watermelon crop leaf minor, thrips, and the fruit fly are major insects. While Downy Mildew, Powdery Mildew, Wilt, Anthracnose, and Gummy Stem Blight are the major diseases.
Timely control of insects and diseases will help to achieve excellent crop growth. Do not spray during the peak pollination period.