Advisory ArticleAgroStar Agronomy Centre of Excellence
One pest that defoliate the mustard crop after one
fortnight of sowing, know about that insect
Larvae of the mustard saw fly defoliate the crop at early stage i.e. 15-20 days after sowing.
Population is increases as the temperature and relative humidity increase in environment.
The larvae are dark green in color and have eight pairs of legs on its abdomen.
Larva on slight disturbance, falls down on the ground and behave just like a feign death and at the same time, it also expels irritant liquid and get protection from its natural enemies.
If incidence occurs every year, raise white mustard, reddish or cress or turnip of 2-3 rows around the mustard field as attractant.
More than one larva can be seen on plants and do damage by making numerous holes on leaves.
Under higher incidence, they defoliate the plants and necessity arises for re-sowing.
Give seed treatment with imidacloprid 70 WS @ 700 g per 100 kg of seed.
Maintain weed free field and follow interculturing periodically as far as possible.
If infestation seems to be increasing, give irrigation. Most of the larvae die due to drowning effect.
Collect & destroy the larvae at morning and evening hours.
On initiation, spray neem oil or bitter guard oil or ready to use neem base pesticides.
Spray Bouveria bassiana, fungus base powder @ 40 g per 10 lit of water.
On having the larval population of 2 larvae per sq. feet (ETL); spray dimethoate 30 EC @ 10 ml or quinalphos 25 EC @ 20 ml per 10 lit of water.
Dust formulations can be adversely affected not only to the environment but also to its natural enemies; hence we have to avoid such insecticides.