Source: FreshPlaza [summ. Mod.DHA, edited]
The Colombian Agricultural Institute (ICA) and the Ministry of Agriculture and Rural Development confirmed the presence of _Fusarium_ Tropical Race 4, Foc R4T, in a single Cavendish banana plant at a farm in Magdalena department. The plantation has over 190 000 banana plants on ca. 100 hectares. Samples were analysed by ICA Phytosanitary Diagnostic Laboratory and the diagnosis confirmed.
Five more samples from the same farm were negative for Foc R4T. Additional 40 samples were taken from the same and neighbouring lots. As part of the outbreak delimitation process, authorities are now taking another 170 samples in a 5 km [3.1 mi] radius, which covers a total of 7 farms.
The protocols established for the control and prevention of the spread of the fungus have been activated. A risk map will also be prepared to identify crucial sites. Authorities say they are confident to be able to contain the outbreak thanks to the country's previous experience with managing _Fusarium_.
[Panama disease of banana (PD, also called fungal or fusarium wilt) is caused by the soil-borne fungus _Fusarium oxysporum_ (previously f. sp. _cubense_). Symptoms include yellowing, wilting, and streaking of pseudostems; affected plants die rapidly. The pathogen is spread by infected planting material, mechanical means (including human and insect activities), soil and water.
Disease management for PD is difficult and mostly relies on phytosanitation for pathogen exclusion. The fungus can survive in the soil for decades; consequently, crop rotation with non-hosts is not likely to control the disease effectively. No effective chemical or cultural control measures are available. Integrated approaches have been developed (ProMED post 20090419.1483), which may include cultural practices, certified clean planting material, and biocontrol agents such as _Trichoderma_ species (for example, ProMED post 20160317.4102576 and see link below). Breeding programmes and molecular techniques are being used to develop crop cultivars with increased resistance or tolerance to the different fungal strains. Constant vigilance is required in areas where the fungus is present to prevent flare-ups and recognise emerging new strains.
Several races of the pathogen exist, varying in host range. Cavendish banana varieties (cultivars within the _Musa_ AAA group, see links below) replaced the original eating varieties (such as Gros Michel) because they are resistant to the original fungal strain. They include most of the current commercial eating bananas. Cavendish-affecting strains, such as temperate (subtropical) and tropical races 4 (TR4), as well as a new strain of race 1 (ProMED posts 20210105.8075029, 20101223.4510), have emerged since from Asia and Oceania.
In recent years, TR4 has been reported in the Middle East, Africa and Asia. A previous detection in Colombia (ProMED posts 20190820.6630576, 20190712.6564489) was the 1st confirmed report of TR4 in the Americas. Since TR4 has recently also been confirmed in Peru (ProMED post 20210414.8308193), several countries in the region have issued official alerts. TR4 is of great concern worldwide; development of TR4-resistant cultivars has become a top priority for many national banana industries (see previous ProMED posts in the archives).
Colombia, with departments:
South America, overview:
PD symptoms on banana:
_F. o._ f. sp. _cubense_ culture:
Information on Panama disease:
Information on race TR4:
FAO emergency project for TR4:
_F. oxysporum_ taxonomy and synonyms:
Information on _Trichoderma_ species and use as biocontrol agents:
Cultivars and hybrids of banana and plantain: