Mite for a mite and shot in the trunk

By Kumudini Hettiarachchi

A part of Sri Lanka's coconut country is in danger. A mite has affected the whole of the Puttalam district since December 1997, but now about 75% of the cultivations have been rid of this pest due to quick action by the Coconut Research Institute in Lunuwila.

Detailing the anti-mite programme, the Acting Director of the Institute, Chitranganie Jayasekera said the mite was first found in one village in Kalpitiya. Specimens were sent to the United Kingdom for identification and the CRI was informed that it was a mite named aceria guerreronis, a species which was not particularly harmful. But when they found that the mite spread quickly across the whole of the Puttalam district, upto Chilaw, they sent more samples to Brazil and it was identified as "dangerous".

Spread by the rain and the wind, the mite affects young coconuts, sucking out the juice from the nuts, leaving them deformed. It also results in immature nutfall. In Kalpitiya, cultivators say the coconuts look as if they are suffering from "hori" (sores).

Ms. Jayasekera said the mite had affected about 20 to 30% of the coconut yield in the Puttalam district. The Institute started a vigorous campaign to combat it by deploying more than 100 officers for over five months in the area to inject the chemical, monochrotophos, into the trunk of each and every tree. "The application of the chemical by cultivators is banned. Only the CRI is allowed its use for the red weevil and the coconut caterpillar, under strict supervision."

"Two holes are made in the tree trunk using an electric drill and 20 ml of the chemical injected," she said on the application required to free cultivations of this mite. "That's why so many officers had to be stationed in the area." Farmers had been asked to harvest the mature bunches before this was done, because no harvesting of coconuts is allowed for 45 days after the chemical is injected. Some cultivators had even agreed to destroy trees which had been badly affected.

The Acting Director said, "Now about 75% of the problem has been solved. The CRI has also found a harmless predator mite which destroys this one. The predator mite is being bred in the laboratories. Entomologists have also come up with an easy chemical concoction — a mix of neem oil and garlic — which farmers themselves can make at home which is very effective against the mite.

"As coconut transportation is the way in which the mite could also spread to distant areas, the Agriculture Ministry has banned the transport of fresh nuts and fresh husks from the Puttalam district to any part of the country," she said, adding that though this has affected the income of farmers, they could still take husked nuts.

Asked about a belief among farmers that the braying of donkeys, prevents the mite from attacking the coconuts, Mrs. Jayasekera said there was no evidence to substantiate it.

Beautiful light brown donkeys, in pairs or groups, are part of the Kalpitiya landscape and Kalpitiya coconut cultivators were quite vociferous on this view. They alleged that about 2000 donkeys had been living in the "wild" in Kalpitiya, particularly in the 800-acre zone demarcated for joint Air Force-Army exercises.

"Most of the donkeys have been killed in the bombings and joint exercises. So they don't bray any more and it has led to the coconuts being afflicted by this virulent disease," Simon Mudalali said, while several others nodded in agreement in the town of Palliavasalthurai, on the Palavi-Kalpitiya Road.

More Plus

Return to the Plus Contents