New PB Knot technology to keep pink bollworm at bay tested in Kurnool district of Andhra Pradesh

New technology of PB-knot rope used to disrupt mating of pink bollworm pest in cotton fields of Kurnool, India. Imported from Japan, the rope releases high doses of female sex pheromone to confuse male moths, resulting in death and preventing mating. Timing of tagging is key to success, implemented on 50 acres with 30 small & marginal farmers.

Pink bollworm is considered a dreaded pest of transgenic cotton, the infestation of which ranges from 30-90% of the cropping area, at times impacting yield to the extent of 90%.

The new-generation insecticides have become redundant due to the cryptic nature of the insect, which spends the majority of its lifecycle in the closed boll. The damage to the crop can only be recognised at the time of the boll opening when it is too late.

Given this background, the new technology of using PB Knot rope to cause mating disruption’ is adopted in demonstration fields in Gujarat and Maharashtra, which comes as a new ray of hope for cotton farmers. The technology, originally developed in Japan by Shin Etsu, a chemical company, is imported by Pesticide India Limited.

In Andhra Pradesh, this project has been implemented this year in an extent of 50 acres of cotton field in Julakallu village of Kurnool district, involving thirty small and marginal farmers.

A PB 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 over the 50 acres.

“Generally, the female pink bollworm releases 3 mg of sex pheromone whereas each PB Knot releases around 158-160 mg. The high dosage confuses the male moth in locating the actual female, and its futile search for the female partner eventually results in the death of the male adult, thus hampering the mating process,” explains M. Sivaramakrishna, scientist at RARS (Regional Agricultural Research Station), who is in charge of the project.