Disease Update - August 9, 2004: Blue Mold has been reported in southern Wisconsin, Massachusetts, and southern Ontario, Canada. During the past week, we received reports of blue mold from 3 new locations across the northern tier of the North American growing regions. One infection is in a 2-acre field in Dane County, WI where 60-70% of the plants have fresh lesions with active sporulation. The southern Canada outbreak occurred in Norfolk County near the town of Langton. Less than 1 acre of a 20-acre field is affected. Fresh lesions are present with active sporulation. Blue mold was discovered in the Connecticut River valley in western MA near the town of Hadley. Disease was confirmed on one plant at the edge of a field, in a favorable area near the river. Evidence suggests that the initial infection occurred in late July. Sprays of Acrobat, Dithane, and Quadris had been applied on at least a weekly basis, which has likely been very helpful in containing this outbreak. We also have an update in from the NC mountains. Frank Bolick states that while the weather has been favorable for disease development for most of the growing season, the use of resistant varieties and proper control methods for non-resistant varieties has prevented rapid spreading of blue mold in and around the Avery County area. Thus, the threat of major damage from this year's epidemic appears to be fairly low.
The Weather... A frontal system now in the Midwest will advance to the south and east over the next two days. Chance of showers or thunderstorms in the Great Lakes and northern Ohio Valley on Monday. The chance of rain will move into the Northeast, mid-Atlantic, Ohio Valley, and parts of the southern Appalachian Mountains on Tuesday. Sunny to partly cloudy and dry to the south and east of this system until one gets to the far south.... where showers and thunderstorms are possible both days along a dying stationary front.
The Forecast... On Monday.... trajectories move to the northeast from the various sources. Impact on other regions should be minimal. The more favorable conditions for disease development will occur near the front. Moderate Risk for southern WI and southern Ontario. Weakly Moderate Risk for the Ohio Valley areas. Low Risk otherwise. On Tuesday.... the chance of long-range transport and deposition increases as the cold front pushes farther to the south and east. Trajectories move to the east, and then northeast after the first 24 hours. Strongly Moderate Risk for southern Ontario. Moderate Risk for tobacco crops in the Ohio Valley, southern New England, southeast PA, and MD. Weakly Moderate Risk for southern WI and the southern Appalachian Mountains. Low Risk otherwise.
TK
Areas at Strongly Moderate or HIGH Risk during the past week: None
Current Sources:
Previous Sources:
Papantla, Veracruz, Mexico
Tepic, Nayarit, Mexico
Pinar del Rio, Cuba
Southern Texas
Local Weather in North Carolina is available from the WRAL-TV5 Weather Center, which also has links to other weather sites.
***** NOTE: These forecasts/outlooks only apply to disease development from airborne transport of spores!!! We do not have the capability to ascertain blue mold development by other means, such as transplanting of infected seedlings, nor will we attempt to do so. Please consult the Extension Service personnel in your area if you have concerns about these matters! *****
This service is provided by the North Carolina State University departments of Plant Pathology and Marine, Earth, and Atmospheric Sciences.