Thursday, 20 April 2023 09:17:00
BUD ROT, OIL PALM – COLOMBIA: (CESAR)
Source: Breaking Latest News [summ. Mod.DHA, edited]
Nearly 78 000 hectares [about 192 740 acres] of oil palm in the department of Cesar are threatened by the growing number of outbreaks of bud rot which could severely affect the plantations. Cenipalma (Oil Palm Research Center Corporation) calculations indicate that, if a regional contingency plan is not implemented to control and overcome the disease, by January 2026 98.8% of oil palms in the department could be affected. Similar situations have already occurred in the department of Magdalena, forcing the elimination of hundreds of hectares of oil palm plantings and replanting with more resistant cultivars.
A forum of stakeholders is being held to discuss phytosanitary issues, projections, and regional strategies for the management of bud rot. For now, there is talk of “isolated foci” in Cesar, but tasks such as proper drainage, avoiding flooding, phytosanitary monitoring, and nutritional management cannot be postponed.
[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. In palms, 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.
https://www.nationsonline.org/maps/colombia_pol_map.jpg (with departments)
South America, overview:
Bud rot symptoms on oil palm:
Bud rot symptoms on coconut and other palms:
Bud rot of palms:
Information on other _P. palmivora_ diseases and hosts:
_P. palmivora_ taxonomy and synonyms:
_Phytophthora_ diseases, impact, and management:
http://www.baumkrankheiten.com/downloads/phytophthora-importance.pdf and via