Explainer: How tech offers hope to save cotton crop

As cotton farmers across Punjab brace for another season, one persistent threat continues to haunt their fields: the pink bollworm.

Known scientifically as Pectinophora gossypiella, this tiny but destructive pest has emerged as a major challenge in cotton-growing regions, especially in southern and central India. It has become a formidable adversary in the agricultural landscape.

The threat

Pink bollworm is one of the most destructive pests affecting cotton crops globally. It has become a major challenge due to the breakdown of resistance to Cry toxins in Bt cotton. The pest targets flowers and green bolls, leading to significant yield and quality losses — often up to 30-40 per cent in the late season. Its cryptic lifecycle, spent largely inside closed bolls, makes detection and control difficult until damage is already done.

Traditional chemical pesticides have proven ineffective, and newer insecticides have lost potency. As a result, alternative strategies like mating disruption technology have gained prominence for their eco-friendly and effective pest control potential.

Mating disruption

Mating disruption technology is an innovative, eco-friendly approach now being recommended by experts at Punjab Agricultural University (PAU), Ludhiana. Researchers Jasreet Kaur, Jasjinder Kaur and Vijay Kumar have been working on sustainable solutions to tackle the pink bollworm menace. Their findings offer a ray of hope for cotton growers looking to reduce pesticide use while maintaining crop health.

Mating disruption involves the strategic release of synthetic sex pheromones into cotton fields to interfere with the pest’s natural mating behaviour. The pheromone used — gossyplure — is a naturally occurring chemical released by female pink bollworms to attract males. By flooding the field with this scent, male moths become confused and are unable to locate actual females, drastically reducing successful mating and, consequently, the pest population.

This method doesn’t kill the insect directly but prevents reproduction, making it a powerful tool in Integrated Pest Management (IPM) programmes. It’s safe for beneficial insects, non-toxic to humans, and reduces the need for frequent chemical sprays.

The cost of the technology is Rs 3,600 per acre for three applications. The total cost, including labour, is Rs 3,850 per acre. For better results, this technology should be used at the square formation stage of the crop on a minimum of 10 hectares.

New ray of hope

The new technology of using Punjab Knot rope to cause mating disruption comes as a new ray of hope for cotton farmers. This technology, originally developed in Japan by Shin Etsu, a chemical company, is imported by Pesticide India Limited. A Punjab Knot rope is essentially a 30-cm plastic vinyl rope which releases female sex pheromones of the insect in large doses.

The rope is tagged at the rate of 160 knots per acre. Generally, the female pink bollworm releases 3 mg of sex pheromone, whereas each Punjab Knot releases around 158-160 mg. The Punjab Knot wire should be tied on the cotton plants at 1-metre distance on the borders of the block, whereas inside the block the wire should be placed 5 metres apart at equidistant points.

The key to the success of this technology lies in the timing of the tagging, which should be done 40-50 days after sowing (square formation stage) and implemented on a community basis across at least 25 hectares (62.5 acres). The cost of Punjab Knot is Rs 3,700 per acre. The total cost is Rs 3,800 per acre. It is a green chemistry solution, safe for humans and the environment.

Why it matters

With pesticide resistance on the rise and environmental concerns mounting, mating disruption offers a sustainable alternative that aligns with modern agricultural goals. It reduces chemical dependency, protects biodiversity, and empowers farmers with a proactive pest management strategy, said Principal Entomologist Dr Vijay Kumar.

Moreover, these technologies are easy to apply, are cost-effective and compatible with other pest-control measures. They allow farmers to continue using insecticides for other major cotton pests without interfering with the disruption process.

As Punjab’s cotton belt continues to evolve, innovations like these could redefine how farmers approach pest control — shifting from reactive spraying to strategic prevention. The pink bollworm may be persistent, but with science and community effort, it doesn’t have to be undefeatable.