How to control Alternaria leaf spot disease in watermelon crop

Alternaria leaf spot disease is seen in watermelon after sowing of the crop.
In this disease, brown colored round spots appear on the leaves and these spots grow slowly and eventually the affected leaves dry up and fall.
For prevention of this disease, spray Carbendazim 12% + Mancozeb 63% WP @ 300 gram/acre or Ketazine @ 300 gram/acre
Spray of Trichoderma viride @ 500 gram/acre as a biological treatment.