A ProMED-mail post <http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>
Date: Fri 5 May 2017 1:33 AM CEST
Source: KRGV 5 [edited]
<http://www.krgv.com/story/35348126/black-rot-disease-affecting-cabbage-growing-season>
Many Rio Grande Valley [Texas] farmers are trying to recoup their losses after the black rot disease invaded their crops. [A farmer] said, "It affected green and red cabbage. I ended plowing under over 75 per cent... It was a real disaster."
Juan Anciso, Texas AgriLife, said other farmers also saw big losses.
About half of the 3000 acres [about 1214 ha] of cabbage this [2017] season was lost due to black rot. "Warm weather for bacteria increases their reproduction rate. We have had a serious problem with black rot.
It's a disease that has been around since cabbage has been around. But we haven't had these problems since the 1980s."
Texas AgriLife will continue to look for black rot resistant strains of cabbage. He said farmers will then be better equipped to turn a profit during unusually warm seasons.
[Byline: Trason Bragg]
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Communicated by: ProMED-mail <promed@promedmail.org>
[Bacterial black rot caused by _Xanthomonas campestris_ pv._campestris_ is one of the most important diseases of brassica crops, including cabbages, turnips, and oilseed rape. The pathogen can also affect cruciferous weeds, which can serve as pathogen reservoirs. The disease affects primarily above ground parts of the plants at any stage of growth. It can cause serious losses in yield and quality, especially in tropical and subtropical regions. Disease development is favoured by high humidity and warm temperatures. Symptoms may vary according to host and environmental conditions and generally include characteristic V-shaped leaf lesions, leaf chlorosis, darkening of vascular tissue, extensive wilting and necrosis. Pre-existing fungal lesions may increase the susceptibility of crops to black rot by providing entry points for the bacteria.
The pathogen is seedborne and can also be spread by mechanical means (including insects), plant debris, water, and wind. Disease management includes clean planting material (seed or transplanted seedlings), cultural practices, removal of weed reservoirs and copper sprays. Some black rot resistant brassica cultivars are available.
Other species and pathovars of _Xanthomonas_ with varying host specificity cause a range of wilts, leaf blights and other diseases on many crops, including vegetables, banana, rice and various fruit trees (see previous ProMED-mail posts in the archives).
Maps
USA:
<http://www.mapsofworld.com/usa/usa-state-and-capital-map.html> and <http://healthmap.org/promed/p/245>
Individual states via:
<http://www.mapsofworld.com/usa/states/>
Pictures
Black rot on cabbage:
<http://eorganic.info/sites/eorganic.info/files/u302/other%20cabbage.JPG>,
<http://www.infonet-biovision.org/sites/default/files/plant_health/pestsdiseasesweeds/952.400x400_0_0.jpeg>,
and
<http://eorganic.info/sites/eorganic.info/files/u302/better%20internal%20black%20rot.jpg>
Affected cabbage fields:
<http://web.pppmb.cals.cornell.edu/dillard/imgveg/br1.jpg>,
<http://ipm.uconn.edu/documents/raw2/Black%20Rot%20of%20Crucifers/Black%20Rot%20of%20Crucifers_0clip_image002.gif>,
and
<http://www.monitor.co.ug/image/view/-/1757022/highRes/495128/-/maxw/600/-/15oqror/-/farm002px.jpg>
Black rot on cauliflower and broccoli:
<http://vegetablemdonline.ppath.cornell.edu/Images/Crucifers/BlackRot_Cruc/BR_CrucFS8.jpg>,
<http://vegetablemdonline.ppath.cornell.edu/Images/Crucifers/BlackRot_Cruc/BR_Cruc4.jpg>,
<http://www.clemson.edu/extension/hgic/graphics/2202/black_rot_of_broccoli_138_300.jpg>,
and
<http://u.osu.edu/vegetablediseasefacts/files/2016/01/Black-Rot-Cauliflower-Bangladesh2014_50Quality-1h4y5dj.jpg>
Links
Information on black rot of brassica crops:
<http://mymebox.org/wp-content/uploads/infonet-biovision/export/default$ct$105$pests.html>,
<http://www.pestnet.org/fact_sheets/cabbage_black_rot_131.htm> (with pictures), <http://ipm.illinois.edu/diseases/series900/rpd924/>,
<https://hortnews.extension.iastate.edu/1999/8-13-1999/blackrotcab.html>,
<https://www.ces.ncsu.edu/depts/pp/notes/oldnotes/vg16.htm>,
<http://www.plantwise.org/KnowledgeBank/FactsheetForFarmers.aspx?pan=20157800494>,
and
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Crucifers_BR.htm>
_X. c._ pv. _campestris_ taxonomy:
<http://www.uniprot.org/taxonomy/340>
Texas AgriLife Extension Service:
<https://agrilifeextension.tamu.edu/>
- Mod.DHA]
[See Also:
2013
----
Bacterial black rot, cabbage - Uganda: (KY,MV)
http://promedmail.org/post/20130429.1679242
2008
----
Brassica diseases - Turkey, Nepal
http://promedmail.org/post/20080213.0572
2007
----
Foliar diseases, brassica crops - UK
http://promedmail.org/post/20070913.3037
and additional items on _Xanthomonas_ diseases in the archives]
Topics
Species
