Control: Spraying carbaryl (4g/litre) during the seedling stage effectively controls the pest.

Aphids: Aphis sp.

Aphids damage the plants by sucking the leaf sap. In young stage, cotyledonary leaves crinkle and in severe cases the plants wither. The leaves of fully grown vines turn yellow and plant loses its vigour.

Control: The aphids can be easily controlled by spraying malathion (0.1 %) or rogor (0.1-0.2 %) sufficiently early before the attack becomes severe.

Fruit fly: Dacus cucurbitae and D. dorsalis

The fruit fly maggots causes severe damage to young developing fruits. The adult fly lays eggs in the flowers. The eggs hatch into maggots, which feed inside the fruits and causes rotting. The fly attack is severe, especially after summer rains when the humidity is high

Control: There is no direct control of maggots because they are inside the developing fruits. The affected fruits should be regularly pinched off and buried in a pit. Spraying carbaryl or malathion 0.15% suspension containing sugar/jaggery @ 10g per litre water at the time of flowering partially check the fly incidence.

Mites

Nymphs and adult mites suck cell sap. White patches appear on affected leaves, which become mottled, turn brown and fall. The pest attains serious proportions during summer. Different stages of mite are found in colonies covered by white-silky webs on lower surface of leaves.

Control: Acaricides like dicofol (0.05 %) and wettable sulphur (0.3 %) gives effective control of mites. Cutting and burning of severely infested plant parts reduces further multiplication of mites.

Diseases

Powdery mildew: Sphaerotheca fuliginea

Symptoms start as white powdery residue on the upper leaf surface. On the lower surface of the leaves, circular patches or spots appear. In severe cases, these spread, coalesce and cover both the surfaces of the leaves and spread also to the petioles, stem, etc. Severely attacked leaves become brown and shrivelled; and defoliation may occur. Fruits of the affected plants do not develop fully and remain small.

Control: Carbendazim (1ml/litre) or karathane (0.5 ml/litre) is sprayed immediately after the appearance of the disease. Repeat the spray 2-3 times at an interval of 15 days.

Anthracnose: Colletotrichum sp.

High humidity and moist weather favour the development of the disease. Symptoms appear on the leaf as black spots, which later turn pink in colour. In case of severe infection, the disease spread to the developing fruit.
Control: Repeated sprayings at 5-7 days interval with dithane M 45 (0.2 %) effectively controls the disease.

Fusarium wilt: Fusarium oxysporum f. sp. niveum

Initially the plants show temporary wilting symptoms, which become permanent and progressive, affecting more vines. The leaves of the affected plants show yellowing, loose turgidity and show drooping symptoms. Eventually, the plant dies. In older plants, leaves wilt suddenly and vascular bundles in the collar region become yellow or brown.

Control: Three sprays of karathane (6g/10 litres) or bavistin (1g/litre) immediately on appearance of initial symptoms at 5-6 days interval controls the disease. Leaves of fully grown vines should be thoroughly drenched during spraying.

Downey mildew: Pseudoperonospora cubensis

The disease is first seen as yellow angular spots on the upper surface of the leaves. Under conditions of high humidity, whitish powdery growth appears on the lower surface of the leaves. The disease spreads rapidly killing the plant quickly through rapid defoliation.

Control: Excellent control of this disease can be achieved with ridomil (1.5 g/litre of water), which must always be used simultaneously with a protectant fungicide such as mancozeb (0.2%) to prevent the development of resistant strains.