Source: The Hans India [summ., edited]
Coconut trees are adversely affected by a strange and peculiar disease called 'black scorch' in parts of East Godavari district [Andhra Pradesh]. Around 880 trees were destroyed on 15 acres [about 6 ha]. Farmers are worried and requested to find a solution to eradicate the disease. They suspect that water released from borewells lead to the problems in the plantation.
Experts from a regional horticulture university visited the area to investigate the nature and cause of the disease. They could successfully prevent the spread to surrounding trees. They also conducted water analysis and soil tests, but couldn't exactly diagnose the nature of the disease. They could not conduct certain other tests due to a lack of funds.
[The name "black scorch" is not widely used for any disease of coconut palm outside of India. However, black scorch of date palm is caused by the fungi _Thielaviopsis radicicola_ and _Ceratocystis paradoxa_, either alone or as a coinfection (see ProMED post 20210806.8573238). In coconut, _C. paradoxa_ is known to cause stem bleeding disease if it infects wounds in the trunk. Since these fungi can cause a range of symptoms on the host, this may be the pathogen referred to above. External stress factors are thought to increase host sensitivity to infection.
Not much appears to be known about the epidemiology of the black scorch fungi. Other species in the genera can be soil borne; spread may also occur by water, mechanical means (for example on cutting tools), and with plant material. Beetles have been reported as important vectors in some hosts. Disease management for _C. paradoxa_ may include orchard sanitation (burning of infected plant matter or whole palms), disinfection of cutting tools and wounds resulting from harvesting or frond pruning, as well as sprays of copper-based fungicides.
Outbreaks of stem bleeding of coconut have been reported from India previously (e.g. ProMED post 20120530.1149915). The suggestion that a release of water into the plantation may have led to the spread of the fungus is plausible but would require the pathogen to have been already present at the site.
India (with states):
Andhra Pradesh districts:
Stem bleeding disease symptoms on coconut:
Black scorch symptoms on date palm:
Stem bleeding disease of coconut:
https://srjcoconutconsultancy.com/stem-bleeding-disease/, and via
Information on black scorch disease of date palm:
_C. paradoxa_ taxonomy and synonyms:
Other fungal taxonomy via:
List of major diseases and pathogens of coconut palm: