Pink bollworm threatens cotton crop again even as options to fight it taper

Pink bollworm can inflict locule damage to the extent of 55% and can reduces seed cotton yield by up to 90%. It impacts the lint quality primarily

Gagandeep Singh of Burj Jabraan village in Mansa district of Punjab has sown cotton on about five acres of land this year.

If not for quick control measures, Singh wouldn't have managed to save his crop from the Pink Bollworm pest, which has infested several farms in his districts and other cotton growing regions of Bhatinda and Fazilka.

Singh says the attack this year has come much sooner than the last, due to the near absence of rainfall in the early part of the sowing season.

“Last year, we lost a considerable amount of our produce due to the pink bollworm (called Gulabi Sundi in local parlance), but this year, as soon as I saw minor infestation of the pest in about 2.5 acres, I started taking precautionary measures. This has lowered the impact for now,” Singh told this reporter over phone.

Many other farmers have not been as lucky as Singh to spot the pest at the early stages. They stand to lose a significant amount of yield as pink bollworm just sucks up a cotton plant from within.

Scientists and researchers working on the field say that all the early sown cotton in Punjab and Haryana, and which has crossed 45 days of its life cycle, has become susceptible to the pest.

“The late sown varieties--those sown around May-end--have yet not reached a stage where they become susceptible to pink bollworm,” Bhagirath Choudhary, Founder Director of the South Asia Biotechnology Centre (SABC) said.

He said pink bollworm has a lifecycle of 30 days, while the cotton crop in North India takes about 170 days to harvest.

This means that in crops that have already been in the field for at least 45 days, there is a chance of pink bollworm germinating 3-4 times till they are harvested.

“This will be devastating for farmers as the yield loss due to pink bollworm attack could be anything between 30-90 per cent,” Choudhary said.

PINK MENACE

• The first pink bollworm outbreak in India was reported in 2013-14
• The pest has a life cycle of 30 days, while the cotton crop in North India takes about 170 days to harvest, say experts
• This means that in crops that have already been in the field for at least 45 days, there is a chance of pink bollworm germinating 3-4 times till the crops are harvested
• Yield loss due to the attack could be anywhere from 30%-90%
• It has heavily infested cotton of Punjab, Haryana, and Northern Rajasthan for the past few years

So what exactly is pink bollworm and what makes it so devastating?

According to various studies and a note put out by the SABC, pink bollworm or Pectinophora gossypiella, is one of commonest pests to infect cotton farms across the world and in India where it has emerged as a major threat over the past few years.

The outbreak of pink bollworm was first reported in 2013-14 somewhere in Gujarat from where it quickly multiplied and spread to other parts of the country such as Maharashtra, Andhra Pradesh and Telangana.

Since the past few years, pink bollworm has heavily infested cotton of Punjab, Haryana and Northern Rajasthan, which are the major cotton growing areas of the North.

Annually, cotton is grown on 12-12.5 million hectares in India and much of this has been under threat of pink bollworm the past few years.

According to SABC, pink bollworm can inflict locule damage to the extent of 55 per cent and reduces seed cotton yield by 35-90 per cent. It impacts the lint quality primarily.

Moreover, PBW infestation is reported to cause rosette flowers, drooping flowers and premature opening of bolls, resulting in stained immature fibre and poorer quality of cotton production.

The way out

Scientists and field researchers say there are mainly three ways to deal with pink bollworms.

The first is the mating disruption technique, where the pink bollworm production cycle is disturbed in order to control pest population.

The second is releasing sterile male moths in the fields so that when they mate with female moths, there is no reproduction. The third technique is extensive use of advanced varieties of BT cotton seeds, which are naturally resistant to pink bollworm.

The US, itself a a big cotton producer, has used all three techniques in combination to handle pink bollworm.

“India can look at mating disruption and use of BG-3 seeds to deal with this problem once and for all,” Choudhary said.

The other option is to exponentially raise the number of pesticide sprays, he says.

“One has to spray pesticides after every 7-8 days to control pink bollworm, which means that after 50 days in the field, the crop will require one dose of pesticide after every 10 days to prevent the spread of the worm,” Choudhary said.

Prior to the advent of pink bollworm, the average number of pesticide sprays on cotton crops had come down to just 2-3, as the seeds available then were strong enough to resist pests.

With pink bollworms, that luxury is no longer available.