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Date: 3 Jan 2009
Source: KRQE News 13, Associated Press (AP) report [edited] <http://www.krqe.com/dpp/news/environment/enviornment_ap_nm_chile_yield_down_200901031425>

New Mexico chili yield down due to disease

A combination of too much rain, wind, hail, insects, and hungry animals made it tough for New Mexico's chili farmers -- especially in Luna County and the Las Uvas Valley in southern New Mexico -- to produce their fiery crop.

Now that the 2008 harvest has wrapped up, early results indicate the chili yield is down 20 to 30 percent, said Stephanie Walker, extension vegetable specialist and chili breeding program researcher at New Mexico State University.

For the 3rd straight year, excess moisture led to the spread of bacterial leaf spot, a destructive disease that causes the plant to lose leaves and not produce peppers.

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ProMED-mail
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[Bacterial leaf spot (BLS) is considered the most destructive leaf disease of capsicum and is caused by _Xanthomonas vesicatoria_ (previously _Xanthomonas campestris_ pv. _vesicatoria_). There are a number of strains of the pathogen and some can also affect tomato.
Solanaceous weeds may act as pathogen reservoirs. Symptoms include necrotic leaf spots, premature leaf drop, and spotting of stems and pods resulting in unmarketable fruit. Disease progress can be very rapid in warm, damp weather and the disease may spread quickly into neighboring crops.

The bacteria can enter the leaf through stomata and wounds and are spread by mechanical means, splashing rain and infected materials such as transplants, plant debris, soil and seed. Under favorable conditions, one infected seed in 10 000 may lead to 100 percent infection of plants in a field. Disease management is difficult and includes use of clean planting material, crop rotation and preventative bactericidal sprays. Crop cultivars with various levels of resistance to the different bacterial strains are available, and cultivars with a general resistance to all strains are being developed.

In New Mexico, BLS epidemics in chili crops resulting in significant crop losses have been reported previously.

Maps
USA:
<http://www.mapsofworld.com/usa/usa-road-map-enlarge-view.html>
and <http://healthmap.org/promed/en?g=5481136&v=34.5,-106.001,5>
US states:
<http://www.census.gov/geo/www/us_regdiv.pdf>

Picture gallery of bacterial leaf spot of capsicum:
<http://vegetablemdonline.ppath.cornell.edu/PhotoPages/Peppers/PepperLeafSpot/LSPepperPhotoList.htm>

Links
Capsicum BLS fact sheet:
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Pepper_BactSpot.htm>
BLS disease information:
<http://www.agrisupportonline.com/Articles/bacterial.htm>,
<http://www2.dpi.qld.gov.au/horticulture/3010.html>  and <http://ag.arizona.edu/plp/plpext/diseases/vegetables/pepper/pepbls.html>
Information on capsicum diseases, including BLS:
<http://plantpathology.tamu.edu/Texlabn/vegetables/Pepper/pepper.htm>
Chili diseases in New Mexico:
<http://www.cahe.nmsu.edu/pubs/_circulars/circ549.html>
Genus _Xanthomonas_ taxonomy and species list:
<http://www.bacterio.cict.fr/xz/xanthomonas.html>.  - Mod.DHA]

[see also in the archive:
2008
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Undiagnosed diseases, vegetable crops - USA: (GA) 20081010.3207
2004
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Regulated plant pests, detection, September 2004: EPPO 20041110.3037 Bacterial spot, tomato, pepper - Turkey (Antalya) 20040204.0412
2003
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Regulated plant pests, detection, March 2003: EPPO 20030506.1128 Bacterial spot, pepper - Turkey 20030315.0644
2002
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Regulated plant pests, detection, Jul 2002: EPPO 20020822.5109 Plant pathogens, intercepts, EPPO 20020717.4782 Quarantine plant pathogens, food crops - Spain 20020107.3186
2001
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Xanthomonas spp., plum, tomato, pepper - Slovenia 20010914.2220 Bacterial spot disease, tomato, pepper - Tanzania 20010908.2155 Bacterial spot disease, pepper - Turkey 20010907.2152]