he scientists at the Punjab Agricultural University, Ludhiana, have issued advisory for managing fall armyworm in maize. Tracing the history of the insect, Dr P.K. Chhuneja, Head Department of Entomology, PAU, revealed that the fall armyworm insect is native to tropical and subtropical regions of the Americas and a noxious pest of the maize.
It was first seen in Africa in 2016 as accidental introduction into the continent and soon spread to 40 African countries within one year. In India, the pest was reported in May 2018 in Karnataka, and within a year, it had infested almost all the states of the country. In Punjab, it was first noticed in the farmers’ fields in August 2019, and by end September, the insect was found infesting late sown fodder maize in various districts.
In the current Kharif season, its infestation has been reported in Jalandhar, Hoshiarpur, Ropar, Pathankot, Patiala and Fatehgarh Sahib Districts. Dr Chhuneja informed that the fall armyworm prefers to feed on 10-40 days old crop, therefore, at this time, farmers are advised to be highly vigilant for its attack in their fields as the crop is currently at the most preferable stage for the pest. He further added that timely control at this critical stage will reduce the population build up that will minimize the possibility of subsequent damage at the flowering stage.
HOW TO SAVE THE CROP, SUGGESTS PAU
“Correct identification, vigilant monitoring and immediate control measures are keys to curtail its damage,” cautioned the scientist, while clarifying that the larva can be identified from four spots in square pattern at tail end and white coloured inverted Y-shaped mark on the head. The larvae vary among greenish brown, light brown or light grey in colours. The female lays eggs in groups of 100-150 eggs on lower or upper surface of the leaves. Young larvae feed by scraping the leaf surface making papery windows. Later on, the larvae prefer to damage the central whorl leaves feeding voraciously causing round to oblong holes with large amount of fecal matter. The damage starting in patches spreads rapidly in the entire field if not monitored carefully and managed timely.
Dr Chhuneja stressed on management of this invasive pest right from its appearance to minimize its multiplication and spread in successive generations. He advised the farmers to take following measures:
- Grain crop sowing must be completed by June 30. This will help in implementation of management strategies on area wide basis. The monsoon rains will also help in reducing the pest load on the crop during its most preferred stage.
- Fodder maize sowing should be restricted upto August15 only. The late sown fodder crop, as per the last year experience, may have higher pest incidence.
- Late sowing would also increase the carry-over of the pest.
- Avoid staggered sowing of maize in the adjacent fields to minimize the continuous availability of susceptible stage of the crop to the pest.
- Avoid planting of fodder maize at high density by usingrecommended seed rate (30kg/ acre) with line sowing method.
- Follow mixed-cropping of fodder maize with bajra /cowpea/ sorghum to provide a physical barrier to rapid spread of pest within the field.
- Apply recommended doses of fertilizer and irrigation to help crop growth andrecovery from damage.
- Egg masses in case of fall army worm are found on both sides of the leaves andcan be destroyed as these are visible with naked eye.
- As soon as the pest appears, spray the grain crop with0.5 ml Delegate 11.7 SC (spinetoram) or 0.4 ml Coragen 18.5 SC (chlorantraniliprole) or 0.4gMissile 5 SG (emamectin benzoate) per litre of water.
- Use 120 litres of water per acre for up to 20 days old crop and increase the quantity up to 200 litres as per crop growth.
- For effective control, nozzle of the sprayer must be directed towards whorl of the plant.
- In fodder maize, spray Coragen 18.5 SC and observe a waiting period of 21 days before harvest to ensure safety of animals.