ProMED
http://www.promedmail.org

Source: Colombian Agricultural Institute (ICA) [in Spanish, machine trans., summ. Mod.DHA, edited]
https://www.ica.gov.co/noticias/ica-cesar-fortalece-pudricion-cogollo-palma

To strengthen the fight against bud rot in palm crops, the Colombian Agricultural Institute (ICA) is raising awareness about the importance of applying phytosanitary measures to combat the disease. ICA has been working with the Oil Palm Research Center Corporation (Cenipalma), to identify early outbreaks and provide necessary tools for management. The importance of prevention, monitoring and timely intervention is being emphasised. Bud rot represents a serious threat to oil palm production in the region.
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Communicated by:
ProMED

[While a number of fungi can cause bud rots in palms, the disease caused by the oomycete _Phytophthora palmivora_ has emerged as the main threat to Latin American commercial oil palm (_Elaeis guineensis_) monoculture since the early 2000s. Tens of thousands of hectares of palms are affected with entire estates destroyed in Panama, Colombia, Suriname, Brazil and Ecuador; the disease is the limiting factor for oil palm cultivation in the region.

Trees of all ages can be affected; they also become more susceptible to secondary insect or pathogen infestations or adverse environmental factors. Symptoms start with discolouration of the spear leaf followed by extensive frond rots as the infected leaf unfolds. The rot progresses into the leaf base killing the single growing bud and thus eventually the tree. Disease incidence is usually more severe in high humidity.

The pathogen enters the host via the crown. It is spread by wind splashed rain, mechanical means (including insect activities, cutting knives) and with infected plant or other material; it can remain dormant in the leaf base during dry conditions. Disease management may include cultural practices (phytosanitary measures, nutritional improvements), removal and burning of severely affected palms, as well as treatments with appropriate agrochemicals (for example copper compounds) at or before onset of symptoms. Different palm varieties or hybrids may show different levels of susceptibility to bud rot. For oil palm, breeding programmes using possible bud rot resistance genes from _E. oleifera_ (indigenous to the Americas) are in progress.

_P. palmivora_ is known to affect more than 150 tropical hosts, including black pod of cocoa (e.g. ProMED post 20220913.8705557). New strains that spread faster and are more difficult to control are emerging.

Pictures
Bud rot symptoms on oil palm:
http://www.scielo.org.co/img/revistas/agc/v32n3/v32n3a11f1.jpg and
https://apsjournals.apsnet.org/cms/10.1094/PHYTO-09-15-0243-RVW/asset/images/large/phyto-09-15-0243-rvw_f2.jpeg
Bud rot symptoms on coconut and other palms:
https://www.ctahr.hawaii.edu/nelsons/palms/coconut_heart_rot_1.JPG,
https://www.ctahr.hawaii.edu/nelsons/palms/cocorot-crown.jpg and
http://www.extento.hawaii.edu/kbase/view/files/pictures/Img0013.jpg
_P. palmivora_, micrograph:
https://agenciadenoticias.unal.edu.co/fileadmin/legacy/AgenciaNoticias_140915-01_11.jpg

Links
Bud rot of palms:
https://edis.ifas.ufl.edu/publication/PP144,
https://apps.lucidcentral.org/ppp_v9/text/web_full/entities/coconut_bud_rot_140.htm,
https://agenciadenoticias.unal.edu.co/detalle/more-aggressive-isolates-of-oil-palm-bud-rot-identified,
https://doi.org/10.1094/PHYTO-09-15-0243-RVW (review) and
https://doi.org/10.1017/S0014479703001315 (review)
Information on other _P. palmivora_ diseases and hosts:
https://www2.ctahr.hawaii.edu/adap2/ascc_landgrant/Dr_Brooks/BrochureNo12.pdf
_P. palmivora_ taxonomy and synonyms (partly reclassified):
https://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=194605,
https://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=194605 and
https://www.speciesfungorum.org/GSD/GSDspecies.asp?RecordID=900853
_Phytophthora_ diseases, impact and management:
http://www.baumkrankheiten.com/downloads/phytophthora-importance.pdf and via
https://edis.ifas.ufl.edu/publication/hs254
Cenipalma:
https://www.cenipalma.org/
- Mod.DHA