Vincentians being urged to be on lookout for signs of Citrus Greening

A plant disease, said to be just as deadly as Black Sigatoka, is making its rounds in the region; but this one is affecting citrus trees.{{more}}

At last week’s consultation on the banana plaguing Black Sigatoka disease, plant protection specialist of the Food and Agriculture Organization (FAO) Dr Vujayanti Lopez, informed the stakeholders present at the Ministry of Foreign Affairs conference room that Citrus Greening, also called Huanglongbing or yellow dragon disease, is one of the more serious diseases of citrus that has been discovered in the Caribbean.

“Right now we have it in Jamaica and Belize, and we suspect it’s in Dominica,” Lopez said.

“It’s just as bad as Black Sigatoka in banana; so, that is something that everybody in the region has to look out for.”

Citrus Greening disease is thought to have originated in China in the early 1900s. The disease is primarily spread by two species of psyllid insects. One species, the Asian citrus pysllid, Diaphorina citri, has been present in Florida since 1998. The bacteria itself is not harmful to humans, but the disease has harmed trees in Asia, Africa, the Arabian Peninsula, and Brazil. There are three strains of the bacteria, an Asian, an African version, and a recently described American strain, discovered in Brazil.

The most characteristic symptoms of citrus greening are a blotchy leaf mottle and vein yellowing that develop on leaves attached to shoots, showing an overall yellow appearance. Fruit from diseased trees are small, often misshapen, and typically, some green colour remains on ripened fruit. On the Mandarin orange, fruit may develop an uneven ripening, such that they appear half orange and half yellow. This symptom is the origin of the common name “greening.” Yields are almost non-existent, and remaining fruit is rendered worthless, due to small size, poor colour, and bad taste.

Citrus fruits consist of oranges, pineapples, grapefruit, tangerines, limes, and lemons. The Caribbean countries which export citrus fruit are Belize, Jamaica, Puerto Rico, Guadeloupe, Dominica, Martinique & Trinidad & Tobago.

Dr Lopez said that attention needs to be paid to the disease by all countries in the region, although all are not involved in the large scale production of citrus fruits.

“I know citrus is such an important crop everywhere. Everybody has one or two trees in your back yard so we have to be vigilant here,” she noted. (JJ)