ProMED

Source: Louisiana State University [summ. Mod.DHA, edited]
https://www.lsuagcenter.com/articles/page1714072665511

Louisiana's warm, humid weather provides a conducive environment for plant pathogens to establish and spread quickly. As a result, an important plant disease called southern blight caused by _Athelia rolfsii_ has started to show up in Louisiana vegetable and ornamental production.

The fungus can cause diseases on various economically important vegetables (cucurbits, aubergine, capsicum, potato, tomato) and ornamental plants. Symptoms appear as wilting and yellowing of leaves and white fungal growth at the base of infected plants; the whole plant eventually turns brown and dies.

[Byline: Raghuwinder Singh]

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Communicated by:
ProMED

[The fungus _Agroathelia rolfsii_ (previously _Athelia rolfsii_, _Sclerotium rolfsii_) is soilborne and has a wide host range in warm, humid regions, including many crops. Many wild and weedy species may serve as pathogen reservoirs. The pathogen survives between seasons as sclerotia (hard, protective structures) which then provide primary inoculum for new crops. It does not produce spores but is spread with soil, farm machinery, and plant debris. Disease management may include deep plowing, phytosanitation, crop rotation of several years, and some fungicide treatments. Biocontrol methods using _Trichoderma_ species and strains are being developed for soilborne fungi, including _A. rolfsii_ (e.g., ProMED post 20160830.4450585).

Pictures
_A. rolfsii_ blight on vegetable hosts:
https://cdn.mos.cms.futurecdn.net/gjzWrCjQo7khHGmuftWFP9.jpg (tomato),
https://pestoscope.com/wp-content/uploads/2020/04/Chilli_Southern-Blight_1.jpg (capsicum),
https://c8.alamy.com/comp/apfbt5/white-mould-sclerotium-rolfsii-mycelium-around-peanut-stem-base-usa-apfbt5.jpg and
https://nwdistrict.ifas.ufl.edu/phag/files/2014/06/Dufault-WM-symptoms-signs1.jpg (peanut)

Links
Information on _A. rolfsii_ blights:
https://doi.org/10.1079/cabicompendium.49155 (with distribution map),
https://gd.eppo.int/taxon/SCLORO,
http://www.extento.hawaii.edu/Kbase/Crop/Type/s_rolfs.htm,
http://www.pakbs.org/pjbot/PDFs/37(1)/PJB37(1)175.pdf,
https://pestoscope.com/product/southern-blight-2/ and
https://www.gardeningknowhow.com/plant-problems/disease/controlling-southern-blight.htm
_A. rolfsii_ taxonomy and synonyms:
http://www.indexfungorum.org/names/NamesRecord.asp?RecordID=309351,
https://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=901174 and
https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=39291
Information on _Trichoderma_ species and use as biocontrol agents:
https://biocontrol.entomology.cornell.edu/pathogens/trichoderma.php
https://doi.org/10.3852/14-147 and
https://doi.org/10.1007/s00253-010-2632-1
Genus _Trichoderma_ taxonomy and species list via:
http://www.indexfungorum.org/Names/Names.asp
- Mod.DHA]