Diseases Management of Cucurbitaceous Crops
1. Powdery Mildew:
Tiny white superficial spots appear on leaves and stem and they become powder on enlarging. Due to attack of this disease, premature defoliation occurs and plants remain stunted in growth. The fruit too do not set or remain smaller in size.
i) This disease can be controlled by ducting sulphur (sulfex) or spraying Karathane or Moresta @ 2 ml per liter of water.
ii) Abol- waja et al. reported that systematic fungicide nimro at 0.05 per cent, Saprol at 0.1 % Calixin at 0.04 % and Ben late 0.05 5 gave beeter control of powdery mildew in cucurbits.
2. Downy Mildew:
Purplish spots appear on lower surface and yellow spots on upper surface of leaves; fruit do not mature or do not contain right flavor.
Control measures: application of fungicidal spray 9 such as Dithane Z-78, Dithane M- 45, Blitox etc) once a week helps to control this.
Watermelon muskmelon and cucumber is mainly affected by this disease. Light brown spots are formed on leaves which turn to dark brown and then to red, and the leaves present a scored appearance. Circular to oval sunken lesions develops on the disease infected fruits a d the fruit rot later on.
Crop rotation with non – cucurbit crops, use of disease free seeds, seed treatment and spraying of ducting of fungicides are the recommended control measures of this disease.
4. Fusarium Root Rot:
Sudden mid season wilt base of stem becomes dark brown, with a soft mushy cuticle wilt, fruit rot, and young seedling damp off.
Crop rotation and seed treatment with hot water at 550c for 15 minutes followed by treatment with chloride (1 in 1000) are the recommended control measures of these diseases.
Mottled leaf with roughened surface occurs. The green colour completely lacking in fruit. In severe cases the plants are yellow and dwarfed and bear little or no fruit. Aphids transmit this disease.
Growing resistant variety and spraying the crop with Dimathoate (Rogor-30 EC) or Methyl parathion (Metacid – 50 EC) or Oxidomition methyl (Metsyton – 25 EC) 2 1 ml per liter of water for controlling the insect vector are the recommended control measures of this disease.