A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>

[1] Eastern USA
[2] Maine
[3] New York, Massachusetts, Maine, New Jersey, Pennsylvania [4] New York [5] Pennsylvania

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[1] Eastern USA
Date: Fri 26 Jun 2009
Source: Cornell Horticulture News, Cornell University [edited] <http://blogs.cornell.edu/hort/2009/06/26/late-blight-a-serious-disease-killing-tomatoes-and-potatoes-this-year/>

Late blight - a serious disease killing tomatoes and potatoes this year [2009]

Home gardeners need to be on the lookout for late blight -- a very destructive and very infectious disease that's killing tomato and potato plants in gardens and on commercial farms in the eastern United States.
This is the same disease that caused the Irish potato famine in the 1840s.
It has never occurred this early and this widespread in the US.

Petunias, which are closely related to tomatoes and potatoes, can also be infected by late blight and show similar symptoms. Late blight is very destructive. Uncontrolled it will kill plants faster than any other disease.

One source of late blight in New York has been traced to tomato plants imported to garden centers from production facilities in the south.

[via Meg McGrath]

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[2] Maine
Date: Fri 26 Jun 2009
Source: WMTW, Portland News [edited]
<http://www.wmtw.com/news/19872418/detail.html>

Maine Department of Agriculture warns of crop blight

Gardeners must be on the lookout for a plant disease that blackens and kills parts of potato and tomato plants, officials from the Maine Department of Agriculture and the University of Maine Cooperative Extension said on Friday [26 Jun 2009].

"We are urging home gardeners, especially those who may have recently purchased tomato seedling from a big box store, to check for this disease,"
said Jim Dwyer, a University of Maine potato specialist. The month of June's [2009] rainy and cloudy weather has helped the fungus that the causes the blight to spread.

Late blight was detected in potatoes in a commercial field and on tomatoes in a home garden in New York. Large retailers in Maine have also discovered the disease in tomato seedlings stocked in garden centers. The department said that Bonnie Plants of Alabama produced the seedlings, has pulled its stock from sale and arranged for their destruction.

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[3] New York, Massachusetts, Maine, New Jersey, Pennsylvania
Date: Sat 27 Jun 2009
Source: Daily Gazette [edited]
<http://www.dailygazette.com/news/2009/jun/27/0627_maters/>

Blight could be threat to tomatoes

The state Agriculture and Markets Department has identified late blight on Long Island and is also monitoring its discovery by a plant pathologist who bought plants at a home and garden center in Tompkins County. "It's a
fairly serious problem, especially for commercial growers," John Mishanec, Cornell Cooperative Extension, said. The disease could wipe out a field of plants within a week and a half, he said.

Charles Bornt, Capital District Regional Vegetable Program, said he was seeing updated alerts on Friday [26 Jun 2009] showing late blight confirmed in Massachusetts and Maine but not in New Hampshire or Vermont. There are
fungicides that are effective and used on commercial fields, and they could help stem major destruction of vegetable fields, Bornt said. Effective treatment also relies a lot on the weather, he said.

Symptoms of late blight were found [23 Jun 2009] in a commercial field of potatoes, and has been detected this year [2009] in several states, including New Jersey and Pennsylvania, according to state Agriculture and Markets spokeswoman Jessica Chittenden. She said Cornell Cooperative Extension representatives have recorded several instances of the late blight at home gardens on Long Island.

Chittenden said the department is maintaining communication with the Cornell diagnostic laboratory and local Cooperative Extension agencies to determine if and where the disease is spreading.

[byline: Edward Munger Jr]

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[4] New York
Date: Sat 27 Jun 2009
Source: WPTZ.com [edited]
<http://www.wptz.com/news/19881063/detail.html>

Destructive fungus hits local plants

A potentially destructive fungus may be eating away at tomato plants in the area. It's called late blight, and experts with the Plattsburgh Cornell Cooperative Extension said it's got the potential to spread.

Ann Lenox-Barlow said she identified plants with the fungus at a local garden center. She said the center quickly disposed of the plants.

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[5] Pennsylvania
Date: Sat 27 Jun 2009
Source: The Morning Call [edited]
<http://blogs.mcall.com/master_gardeners/2009/06/late-blight-confirmed-in-five-pennsylvania-counties.html>

Late blight confirmed in 5 Pennsylvania counties

According to Beth Guigino, a Penn State vegetable pathologist, late blight has been confirmed in 5 Pennsylvania counties on tomato and potato plants. Late blight has never occurred this early and this widespread in the US.

Late blight thrives in wet weather, so current conditions favor the spread of the disease. Late blight is a serious problem because tomato and potato crops in home gardens could potentially harbor an infestation that could
destroy commercial grower's fields. If the disease is confirmed [in an area], the Extension Office will notify the commercial growers so they can take preventative measures.

[posted by Kate Brandes]

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[Late blight of tomato and potato is caused by the fungus-like organism _Phytophthora infestans_ and can cause 100 per cent crop loss. To a lesser extent, it can also affect other solanaceous crops such as eggplant and
capsicum. The pathogen can affect leaves, stems, and fruit of tomato, causing spots, lesions, and rotting. In potato it affects leaves as well as tubers. The disease can spread rapidly within a crop and destroy it within
a few days. It is spread by contaminated plant and other material, wind, and water. Under favourable conditions, epidemics in tomatoes may be even more rapid than in potatoes.

Disease management requires an integrated approach including phytosanitary measures, removal of solanaceous weeds, and volunteer crop plants serving as pathogen reservoirs, limiting free moisture in the crop, preventative
fungicide treatments of planting material (tomato transplants, potato seed tubers), and fungicide sprays of crops. Crop rotation with non-hosts may reduce available inoculum. While commercial crop cultivars vary in susceptibility to late blight, development of resistant cultivars is being counteracted by the adaptability of the pathogen, with new strains evolving all the time.

Earlier in the current US growing season, late blight was reported in May 2009 in Alabama (ProMED-mail post 20090519.1875), which is reported above as a source of contaminated tomato seedlings, as well as in Florida
(ProMED-mail post 20090109.0083).

Maps of USA:
<http://www.mapsofworld.com/usa/usa-state-and-capital-map.html>  and
<http://healthmap.org/r/00an>
Pictures
Late blight on tomato:
<http://www.omafra.gov.on.ca/english/crops/hort/news/hortmatt/2006/23hrt06a3f1.jpg> 
and
<http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomLeaf/Late_Tom.htm> 

Tomato field destroyed by late blight:
<http://www.apsnet.org/online/feature/BioSecurity/Images/lateblightbolkan.jpg>
Late blight on potato:
<http://www.sciencedaily.com/images/2007/01/070102132649.jpg>  and
<http://www-biol.paisley.ac.uk/bioref/Chromista/potato_blight.jpg>
Links
Late blight fact sheets:
<http://ohioline.osu.edu/hyg-fact/3000/3102.html>  and
<http://vegetablemdonline.ppath.cornell.edu/factsheets/Potato_LateBlt.htm>
Disease history and background:
<http://www.apsnet.org/online/feature/lateblit/>,
<http://www.olympusmicro.com/micd/galleries/brightfield/potatoblight.html>, 
and
<http://www.agric.wa.gov.au/pls/portal30/docs/FOLDER/IKMP/PW/PH/DIS/VEG/FS0401_REVIEW.PDF> 

Late blight information and resources:
<http://www.potato.org.uk/department/knowledge_transfer/fight_against_blight/advice_blight.html> 

_P. infestans_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=232148>
Global Initiative on Late Blight:
<http://gilb.cip.cgiar.org/>.  - Mod.DHA]