BITTER GOURD is often subjected to severe crinkling problem. The problem of crinkling in bitter gourd is caused due to the feeding activities of pests like green jassids, white flies, aphids and mites. Mosaic disease transmitted by aphids and white flies adds to the severity of the problem.
The following measures are found to control the pests resulting in a good crop of bitter gourd free from crinkling problem.
Yellow sticky traps
Yellow sticky traps erected in the garden at the rate of 125 traps per hectare will be helpful in trapping large populations of white flies visiting the garden. The trap is also useful in trapping the migrating aphid population. The traps can be made by using yellow polythene sheets or empty tins painted yellow. The flags made from yellow polythene sheets smeared with castor oil or empty tins painted yellow and smeared with castor oil are set in the garden at different locations. The white flies get attracted to the sticky yellow traps and get stuck.
The spray solution can be prepared by mixing two hundred ml of castor oil with eight hundred ml of Neem seed oil to form one litre of oil mixture.
The oil mixture is emulsified with soap solution, which is prepared by dissolving sixty grams of ordinary soap in five hundred ml of water.
The soap solution is to be added to the oil mixture under violent agitation to form a good emulsion. The emulsion is diluted by mixing with sixty litres of water and the resultant spray solution is filtered and sprayed on the lower surface of the leaves.
The residual population of the pests can be managed by spraying garlic extract on the lower surface of leaves. The spray solution can be prepared by mixing garlic extract taken from 1.2 kg of garlic in sixty litres of water.
Spraying starch solution (kanji water) on the lower surface of leaves at fortnightly intervals controls the pest.