Keeping off whitefly from mint

This tiny pest was ravaging mint crops until one day scientists found out how to deal with it.

This tiny pest was ravaging mint crops until one day scientists found out how to deal with it. According to a study by the Central Institute of Medicinal and Aromatic Plants CIMAP, 19.2 per cent of losses in mint farming in Uttar Pradesh 8212; the largest grower of mint crop in the country 8212; was due to whitefly.

The problem required immediate attention as mint, which is used in a variety of products, from perfumes to icecream, and aromatherapy to juices, was increasingly growing in popularity for the less time it took to mature and ready market.

The whitefly is invisible to the naked eye, being 0.5 mm in size 8212; approximately the point of a pencil tip. It causes widespread damage to potato, tomato and cotton plants. Farmers identify whitefly-infested crop by the curling of leaves, stunted growth and yellow discolouring.

The keen eyes of Dr Dwijendra Singh, a scientist heading the Entomology Division at CIMAP in Lucknow, first caught the whitefly infestation in 1990 in the experimental farm set-up in CIMAP8217;s vicinity. 8220;The whitefly is very hard to sight as it lives on the underside of the leaf and is very tiny. It is necessary to warn farmers about them,8221; said the senior scientist. The institute launched a multi-disciplinary programme involving entomologists and plant breeders to tackle the issue.

Research over three years led them to identify which mint species were most susceptible to whitefly, the lifecycle of the pest and simple pest management solutions.

On evaluating 86 varieties of mint genotypes, 12 less susceptible to whitefly were chosen. Of these, three of the most resistant types were determined. Research showed the Kushal and Himalaya varieties to be most resistant.

It also revealed that the MS1 variety, which was distributed to farmers by the institute last year due to its high-value proposition, was very susceptible to whitefly.

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To study the whitefly, scientists trapped them using yellow sticky plastic boards placed strategically between rows of mint crop for three hours every morning. Whitefly is attracted to the colour yellow, just as the honeybee is to red. These traps were designed specifically by the institute, now available at a minimum price.