ProMED
http://www.promedmail.org

Source: WEE FM Radio [summ. Mod.DHA, edited]
https://www.weefmgrenada.com/grenada-preparing-to-deal-with-the-lethal-yellowing-disease-which-affects-coconut-plants/

The Grenada Ministry of Agriculture is putting plans in place to deal with the lethal yellowing (LY) disease which affects coconut plants. Production levels in other regional countries have been impacted by the disease. The country office of the Caribbean Agriculture & Research Development Institute (CARDI) is working with the International Trade Centre (ITC) and the Coconut Industry Board of Jamaica (CIB) to inform stakeholders and extension workers about control measures and recommended agronomic practices for coconuts. It is important to have information on the disease beforehand.
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Communicated by:
ProMED
[Lethal yellowing (LY) diseases of coconut and other palms are caused by phytoplasmas of the palm lethal yellowing (16SrIV; _Candidatus_ Phytoplasma palmae strains) group. A number of LY strains have been described from the Caribbean, Latin America, Africa, and southern Asia. LY has seriously jeopardised coconut industries in the respective areas. LY-type diseases like Cape St Paul wilt (CSPW) in Ghana, the "maladie de Kaincope" in Togo, and Awka disease (lethal decline, LD) in Nigeria, previously included in the 16SrIV group, have been reclassified as the new group 16SrXXII (Nigerian coconut lethal decline group, _Ca._ P. palmicola strains; see link below).

Symptoms include premature nut drop, blackening of inflorescences, and yellowing of fronds; death of the palm usually occurs within 4 to 6 months. The planthopper _Myndus crudus_ is suspected to be the vector in the Americas, but different vectors may be involved in the spread of LY strains elsewhere. Seed transmission of the pathogens cannot be excluded, some weed species may serve as pathogen reservoirs. Jumps of LY across apparently unaffected coconut populations have been observed, possibly due to aerial spread of infectious vector insects or human activities. Even with strict controls, including certification of nuts and their parent trees, excluding infectious vector insects requires large quarantine efforts.

While LY affects many palm species, at least for coconut palm, susceptibility may vary between cultivars or even within cultivars, depending on the region where they grow. Symptoms can be suppressed by tetracycline treatments, usually applied as trunk injections. The antibiotic inhibits multiplication of the pathogens but does not eliminate them. Therefore, treatments need to be repeated regularly. Commercial control of the diseases mostly relies on phytosanitation followed by replanting with resistant varieties.

Elsewhere in the Caribbean region, an unexplained resistance breakdown of some widely used hybrids occurred in Jamaica (ProMED post 20070522.1643) and is causing great concern. In Antigua, a large scale death of coconut palms was first noted in 2012 (ProMED post 20120801.1223614).

Maps
Grenada:
https://ontheworldmap.com/grenada/large-detailed-map-of-grenada.jpg,
https://www.intotheplanet.com/wp-content/uploads/2016/06/detailed_map_of_grenada.jpg, and
https://promedmail.org/promed-post?place=8702300,34
Caribbean region:
https://www.worldatlas.com/upload/c3/b8/ae/jm-02.png

Pictures
LY symptoms on coconut and other palms:
http://www.growables.org/information/TropicalFruit/images/LethalYellowingFoliarSymptoms.jpg,
https://bugwoodcloud.org/images/768x512/1504005.jpg,
https://bugwoodcloud.org/images/768x512/1504008.jpg,
http://idtools.org/id/palms/symptoms/images/fs_images/LY_Jamaica_2005.jpg,
https://guyanachronicle.com/wp-content/uploads/2017/04/Lethal-Yellowing.jpg (leaf) and
http://www.cphdforum.org/wp-content/uploads/2015/06/LethalYellowingCoconutSymptom.jpg (fruit)
_Myndus crudus_:
http://www.forestryimages.org/images/768x512/0725079.jpg

Links
Lethal yellowing information:
https://www.cabi.org/isc/datasheet/38647,
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5080360/,
https://doi.org/10.1111/j.1744-7348.2011.00480.x,
https://www.cphdforum.org/index.php/2015/06/03/about-lethal-yellowing-of-coconut/,
http://idtools.org/id/palms/symptoms/factsheet.php?name=Lethal+Yellowing,
http://edis.ifas.ufl.edu/pp146 and
https://www.apsnet.org/edcenter/disandpath/prokaryote/pdlessons/Pages/LethalYellowing.aspx
16SrIV LY phytoplasma group taxonomy and species list:
http://www.uniprot.org/taxonomy/85624
16SrXXII classification of some LY-type diseases:
https://doi.org/10.1099/ijs.0.65000-0
16SrXXII LDN phytoplasma group taxonomy:
http://www.uniprot.org/taxonomy/590462
Phytoplasma resource centre:
https://plantpathology.ba.ars.usda.gov/phytoplasma.html
- Mod.DHA]