A disaster is lurking in the form of armyworm attack on paddy fields in Kuttanad, considered a prime granary of Kerala. The infestation of the worms, known as ‘pattalappuzhu’ in local parlance, noticed a week ago, has been spreading rapidly to new areas, threatening hundreds of hectares of paddy crop in their early stages of growth.
Experts say that multiplication of the caterpillar is facilitated by climate change. The death of lakhs of ducks that prey on the caterpillar, owing to the recent bout of bird flu, has also contributed to the unhindered pest attack.
“Dry humid conditions are favourable for the rapid multiplication of the armyworms. Paddy crop up to 30 days of growth are vulnerable to the attack. The worms are voracious eaters and devour most parts of the plant, usually in the evenings,” Ambika Devi, Associate Director, Regional Agricultural Research Station, an institution functioning under the National Agricultural Research Project, told The Hindu .
Scarcity of rain has fuelled the current attack while lack of irrigation facilities has further complicated matters. “The worm infestation has to be contained within 48 hours. Flooding of the fields for three days is an effective method to destroy the worms. The armyworm attacks had occurred three years ago in certain pockets, but they were contained immediately,” she said.
Broken irrigation pipes have resulted in denial of water to certain worm-infested areas in Kuttanad. Low level of water in rivers has added to the problem. Late sowing of paddy has also contributed to the crisis.
“About 4,500 hectares out of 26,000 hectares of paddy sown in Kuttanad have been affected by the worm infestation,” said A.G. Abdul Kareem, Principal Agricultural Officer, Alappuzha. Fields with plants up to 45 days of growth have been hit. Organic insecticides containing garlic, tobacco and bird’s eye chilli (kanthari) extracts are used to kill the worms. He said the fields were being flooded wherever possible.
The worm infestation had been noticed in fields at Chengannur, Mavelikara, Thazhakkara, and Veliyanadu, said Mathew Abraham, Agricultural Officer, Kerala Centre for Pest Management, Moncombu. The cracks in the fields due to drought have helped the insects multiply.
He felt that the loss of over 5 lakh ducks contributed much to the present situation.