Pest

Symptom

control

Red pumpkin beetle

Adults feed on the foliage, buds, and flowers. Grubs feed on roots

Preventive measures like burning of old creepers, ploughing & harrowing of fields after the harvest of crops to destroy the stages of the pest. Beetle should be Collected & destroyed in the early stage of its infestation. Spraying with 0.05% malathion or dusting with 5% malathion dust @ 10 kg/ha.

Melon Fruit fly

Active during March-May. Attack fruits. Reddish dark brown flies with hyaline wings lay eggs under the skin of the fruits; Maggots feed on the pulp of fruits. Infested fruits start rotting and rendered them unfit for human consumption; Fruits show dark-brown, rotten, circular patches and fall off prematurely

Clean cultivation, i.e. remove and destroy all the fallen & infested fruits on daily basis. Deep ploughing to expose hibernating stages.Application of spray baits.Spraying with 0.05% malathion or 0.2% carbaryl at flowering.

Aphid

Colonies of nymphs and adults attack leaves and tender shoots and suck the sap; Leaves curl and dry up.

Remove infested leaves and shoots in the initial stage;Spray 0.02% Pyrethrins 

Disease

Symptoms

Control

Powdery Mildew

Powdery Mildew is favored by high humidity and tends to occur on older leaves first. Symptoms can be found as a white powdery residue mainly on the upper leaf surface. Whereas circular patches or spot are visible on the lower surface of the leaves. In severe infestation, these can be spread, coalesce, and cover both the surfaces of the leaves and may be spread up to the petioles, stem, etc.  Severely affected leaves become brownish and shrivelled and defoliation may also occur. The affected  Fruits plants show stunted growth .

Apply the Carbendazim (1ml/liter of water) or Karathane (0.5 ml/liter of water) sprayed immediately after the appearance of the disease. 2-3 sprays are taken at an interval of 15 days.

Downy mildew

Downy mildew is caused by the fungus Pseudoperonospora cubensis. It is very common in areas of high humidity, especially  under the condition when summer rains occur regularly. The disease is first observed as yellow angular spots on the outer surface of the leaves. In the prevailing conditions of high humidity, whitish powdery growth appears on the inner surface of the leaves. The disease spreads rapidly and destroys the plant through accelerated defoliation.

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.

Bitter Gourd Mosaic

This virus disease is mostly confined to the leaves with symptoms appearing on the leaves in the secondary branches produced at the apical end of the plant. Small irregular yellowish patches are visible on the leaves. Some leaves show vein clearing in one or two lobes of the leaf and severely infected plants show a reduction in leaf size and elongation and/or suppression of one or two lobes. Young developing leaves are completely distorted and malformed with considerable reduction in their size. Some of the leaves show a marked reduction in the development of lamina resulting in a shoe-string effect. The virus is transmitted by five species of aphids.

Spraying of the crop should be done just after germination with chemicals like ; Monocrotophos (0.05%) or Phosphamidon (0.05%) at 10-day intervals to prevent aphid vectors.