"Samples collected in September from affected plants in the citrus-growing areas of the parish were tested locally by the University of the West Indies and the presence of the disease agent, Candidatus liberibacter asiaticus, was deter-mined," the ministry said in a release yesterday. "This finding was later confirmed by the United States Department of Agriculture's Animal and Plant Health Inspection Service Laboratory."
Indicators of the disease
Citrus greening is a bacterial disease which has a severe effect on citrus plants and orchards under 10 years old. The presence of the bacterium can remain undetected for several years without plants displaying any visual symptoms. However, the most typical indicators of the disease's presence are: asymmetric blotchy mottle of the leaves; sectoring of the tree with yellow shoots; heavy fruit fall; small, lopsided fruits with aborted seeds; colour inversion on fruits (ripening from the top instead of the bottom); twig dieback and eventual death of plants.
The bacteria is mainly transmitted to uninfected plants by a small sucking insect known as the citrus psyllid - Diaphorina citri - dis-covered in the island in 2002. In addition, transmission is also possible through the grafting of infected material and/or seeds.
Citrus greening affects most citrus species, including hybrids, cultivars, as well as sweet oranges, mandarins, grapefruits, limes and lemons.
"It should be noted that no country that has reported the presence of citrus greening has successfully eradicated the disease," the ministry said. "However, management programmes have been implemented to reduce the impact of the disease on citrus production."
Control of disease
Control of citrus greening requires an integrated management approach which includes:
Early detection and removal of infected trees.
Vector management using chemical and biological methods.
Use of certified material for propagation.
Use of seedlings produced under cover.
Removal of alternate hosts in commercial growing areas.
Grower education.