Cultivation of Bitter Gourd

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 field after harvest of crop to destroy the stages of pest. Beetle should be Collected & destructed in 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 or 0.05% Malathion or Dichlorvoe (DDVP)

Disease

Symptoms

Control

Powdery Mildew

Powdery Mildew ( Sphaerotheca fuligine) : This disease is favored by high humidity and tends to occur on older leaves first. Symptoms can be found as an  white powdery residue mainly on the upper leaf surface. Whereas  circular patches or spot  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 shows stunted growth .

Apply the Carbendazim (1ml/litre of water) or Karathane (0.5 ml/litre of water) is 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 destroy the plant rapidly through accelarated 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 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 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 the chemical like ; Monocrotophos (0.05%) or Phosphamidon (0.05%) at 10-day intervals prevents aphid vectors.