Bathinda, Aug 21 — As Punjab’s cotton farmers brace for another season, the pink bollworm — a tiny insect but one of the crop’s most destructive foes — looms large. Now, scientists say a new technology offers hope: disrupting the pest’s mating cycle with synthetic pheromones.
Experts at Punjab Agricultural University (PAU), Ludhiana, are recommending mating disruption as a sustainable alternative to pesticides, which have steadily lost effectiveness against the pest. “This is a green chemistry solution that is safe for humans, reduces chemical dependency, and protects biodiversity,” said Dr. Vijay Kumar, principal entomologist at PAU.
Pink bollworm (Pectinophora gossypiella) has become a major challenge in India’s cotton belt after developing resistance to Cry toxins in Bt cotton. The pest attacks flowers and bolls, often destroying 30–40 percent of yield late in the season. Because its lifecycle is largely hidden inside closed bolls, infestations are detected only after damage is done.
Farmers’ reliance on chemical sprays has proved costly and largely ineffective, prompting scientists to push for alternative measures.
The strategy involves releasing synthetic sex pheromones in fields to confuse male moths. The pheromone, gossyplure, mimics signals released by female pink bollworms. When fields are saturated with the scent, males fail to locate mates, reducing reproduction and cutting the pest population over time.
Unlike insecticides, the method doesn’t kill the insects directly but prevents their multiplication. It is non-toxic to humans, harmless to beneficial insects, and reduces the need for frequent spraying.
The cost is estimated at ₹3,600 per acre for three applications, with total expenses (including labour) around ₹3,850 per acre. PAU recommends adoption at the square formation stage of the crop across at least 10 hectares to ensure effectiveness.
One promising innovation is the Punjab Knot rope, developed in Japan and imported by Pesticide India Limited. The 30-cm vinyl rope releases female pheromones in high doses — around 158–160 mg, compared with just 3 mg released naturally by a pink bollworm.
Farmers must tie the ropes at 160 knots per acre, with wires placed 1 metre apart along field borders and 5 metres apart inside. Application is recommended 40–50 days after sowing and, critically, on a community scale across at least 25 hectares.
The cost works out to about ₹3,700–3,800 per acre, comparable to the synthetic pheromone spray.
Punjab’s cotton crop spans over 7 lakh hectares, much of it in the southern belt. With groundwater stress, rising pesticide resistance, and recurring pest outbreaks, researchers say the shift toward eco-friendly control is urgent.
“Mating disruption offers a proactive strategy instead of reactive spraying,” Dr. Kumar explained. “It is cost-effective, easy to implement, and compatible with other pest-control methods.”
Farmers can still use insecticides for other cotton pests without interfering with the disruption system. The larger challenge, experts note, lies in coordinated adoption across villages, since the pest does not respect field boundaries.
Agricultural scientists believe technologies like pheromone disruption could redefine Punjab’s approach to cotton farming. By cutting pesticide use, preserving yields, and reducing environmental damage, they argue, farmers can secure both productivity and sustainability.
The pink bollworm may be persistent, but with science and collective effort, experts say, it need not be undefeatable.
