NCBS working on natural cure for stem borer disease

With the threat of the white stem borer intensifying in coffee plantations all over the State, the Coffee Board recently sanctioned a unique project for scientists at the National Centre for Biological Sciences (NCBS) where they use a ‘naturalistic’ approach by understanding the pest’s behaviour, as a means to arrive at a solution.

At a programme held recently, Dr Shannon Olssen, a chemical ecologist and faculty of NCBS - principal investigator in the project - said, “The aim is to find an ecological solution based on natural balance.”

Why does the white stem borer like coffee? What do they do in a coffee plant? These are some basic questions that the project will aim to understand.

Preliminary investigations have been going on since September at coffee plantations at Chetalli in Kodagu.

While it is too early to come to a conclusion, a number of interesting experiments are being carried out. For example, it has been found that the white stem borer very often lands on leaves of the coffee plant. As a result, the team from NCBS has tried

covering coffee plants with plastic sheets with holes in them, to study how they react.
The approach to the project, according to Olssen, is similar to the ‘push-pull’ technique widely used in corn farms in Africa against stem borers.

This farming technique uses the properties of a certain kind of grass (Napier) and a plant (desmodium) that are planted with the corn to protect crops.

“It is a naturalist and minimalist approach. As of now, we are working on the basis of a hypothesis and cannot say anything for sure.”

Dr Y Raghuramulu, director of research, Coffee Board, said, “How does the insect rest? Where it rests? Whether it has any central means of communication? We do not have information on such aspects. Through the NCBS study, we are not just looking at controlling the pest, but also want to understand its behaviour and entire life cycle.”

The common techniques of dealing with diseased plants are explained by Mohan Kumar, vice-president, Karnataka Coffee Growers Association.  “There are various techniques (to deal with diseased plants) as of now. The diseased plants may be uprooted or put in shade. The stem is scrubbed and chemicals sprayed or pheromone traps are used in the coffee plants.”

Last year, 3,200 hectares of coffee plantations were affected by the white stem borer in the State.

The Arabica variety of coffee is mostly affected by pests. With the State accounting for over half of the coffee production in the country, controlling the pest is undoubtedly a major issue. 

Raghuramulu said that the effort by NCBS is part of a plan to speed up research and development activities on coffee white stem borers, under a high-level steering committee headed by an official of the Ministry of Commerce.

Representatives from the Indian Institute of Science (IISc), University of Agricultural Sciences (UAS) and Indian Council of Agricultural Research (ICAR) are part of the committee.