Financial Times - Going batty over the coconut mite

A new mite that has been quietly spreading across Sri Lankan coconut plantations in recent years is now attacking nuts across many areas and affecting the growth of the coconut.

“This mite is attacking the button nuts (kurumbatti) which results in deformed or stunted growth,” said Ranjit Dias, President of the Coconut Growers Association of Sri Lanka showing The Sunday Times FT last week two of the affected coconuts.

Concern is growing amongst the country’s 700,000 growers and their 440,000 hectares (one million acres) of coconut plantations. This harmful mite (insect) was first discovered in 1997 at Kalpitiya attacking the button nuts.

Now the coconut mite has gradually spread – over the years – to plantations in Chilaw, Puttalam, Negombo, Kurunegala, some areas in Gampaha and the Mahaweli areas. According to official statistics, some 15 to 25 percent of Sri Lanka’s nut production has been affected by the mite attack. While the numbers of coconuts produced may be the same, the amount of kernel per coconut is considerably lower due to the smaller size of the nut.

In 1999 the association held a seminar in Mundal in the Chilaw-Puttalam area where scientists from the Coconut Research Institute (CRI) explained and alerted growers to this problem and announced preventive measures which was to inject a chemical called monocrotophroh to the truck of the tree to kill the insect.

But growers were not in favour as all the matured nuts had to be removed from the tree before this could be applied as it was poisonous and could have affected the kernel. Growers were also reluctant to drill a hole – as expected into the tree to insert the chemical – which could have led to tree decay. It wasn’t a practical solution.

Experts then came up with the neem solution. Here the neem (margosa) oil was to be blended with oil and soap water and applied to the nuts at the crown (top of the tree) and the process had to be repeated depending on the weather and the state of the affected nuts. This was also considered impractical as it was difficult to find that many tree climbers to do the job.

Another solution – tying a polythene bag with sulphur dust enclosed in the affected bunches – also came a cropper due to practical problems in its implementation.

The CRI then came up with what was seen as a permanent solution: introducing a predator (another insect) to attack and destroy the coconut mite. Unfortunately experiments in this connection have gone on for the past three to four years and the CRI has been unable to give a kick-off date for this solution as the predator has to be multiplied in millions for any impact to be achieved.

“In the meantime the industry suffers and growers lose their income. We are told this is a cancerous disease and the worst in the coconut industry history,” Dias said adding that the CRI has asked for assistance from foreign countries without success.

The association, in a bid to reduce the problems of the growers, is suggesting that the government should permit growers to use affected coconut estates for toddy tapping – so that the income of growers could be cushioned to some extent.

“We expect the government to look into the possibility of obtaining the necessary fiscal approval, find suitable toddy tappers and market the product,” he said adding that these suggestions have come after an in-depth study by the association.

“With toddy tapping we can reduce the import of spirits to make arrack,” he said.