“Coconut Leaf Wilt Disease could have been controlled sooner if there was cooperation”

Monday, December 5, 2022 – 01:00

Print Edition

Local

Priyan de Silva

Dr. Nayani Arachchige

Fourteen years after being first detected in Sri Lanka, over 340,000 coconut palms identified as diseased, over 313,000 coconut palms cut down and destroyed, and billions of rupees spent on disease control, coconut growers in the Southern Province continue to be plagued by the Weligama Coconut Leaf Wilt Disease (WCLWD)

Coconut Research Institute (CRI) Deputy Director (Research) Dr. Nayani Arachchige said that the CRI together with Coconut Cultivation Board (CCB) and other related stakeholders including law enforcement authorities have managed to contain the disease to the Southern Province and added that if the coconut growers and the community on the whole had been more cooperative, the disease could have been controlled sooner.

The Weligama Coconut leaf Wilt disease is caused by phytoplasmas and transmitted by infective insect vectors, vegetative propagation or grafting of infected planting material to healthy plants, by vascular connections made between infected and uninfected host plants by parasitic plants, and by seed or embryo transmission. Once infected, a coconut palm will die within two years. There is no known cure and cutting down infected trees and incinerating the crowns is the only practical solution to arrest the spread of the disease.

Dr. Arachchige said that at the initial stage of infection, a coconut tree would bear profusely and growers have second thoughts of cutting down the tree even after they have been noticed to do so by the authorities. The delay causes greater harm as more trees in the vicinity are prone to infection and was one reason that containing the disease has taken so long.

The WCLWD was first detected in the Weligama area in 2008, but had spread from Galle to Tangalle. To prevent the disease spreading further, the CRI demarcated a buffer zone three kilometres wide on either side of the A17 trunk road from Galle running through Angulugaha, Henegama, Akuressa, Kamburupitiya, Kirinda – Puhulwella, Hakmana, Walsmulla, Beliatta and ending in Tangalle.

The Government, by gazette notification No. 1542/7 of 24 March 2008, prohibited the transport of any palm species and their live parts out of the demarcated boundary. Although the prohibition was not strictly adhered to due to various restraints, it was fortunate that the disease did not spread to other coconut growing areas.

The Matara district where WCLWD was first detected has borne the brunt of the disease. Figures obtained from the Coconut Cultivation Board show that up to September 30, 2022, 313,857 diseased trees have been identified in the Matara district.

Growers who complied with the order given by the CCB authorities and cut down the diseased trees were paid Rupees 3,000 per tree more as an initiative to cut and destroy the tree rather than compensation as the cost incurred by a grower to tend to a plant until it starts bearing and the loss of produce is very much more.

Due to WCLWD and other factors such as eating of the coconut by Grizzled Giant Squirrels and the Toque macaque, the annual yield in the Matara district had dropped from 121 million nuts in 2011 to 96 million nuts in 2019 and to 73 million nuts in 2020.

Some growers have been compelled to destroy their whole plantation and plant alternate crops as provisions of the Plant Protection Act prohibits planting any type of palm trees in the areas where WCLWD has been detected.

According to the CCB, WCLWD could be fully eradicated in the near future if the growers and public were more cooperative and if the Government would continue to provide adequate funds.