FORECAST DISCUSSION: Thursday, September 21:
*** September 20 Disease Update: We have our first reports of downy mildew from Virginia and New Jersey *** Steve Johnston in NJ informs us of a serious outbreak of downy mildew in the southern part of the state. Disease was first observed on August 21 on summer squash. During the past month, downy mildew has spread across Salem, Cumberland, and Gloucester counties in southern NJ. It has appeared on the majority of cucurbits grown in that area, primarily pumpkins and muskmelons. Sam Alexander in VA reports that downy mildew has been discovered in Accomack County. This county lies adjacent to Wicomico County, MD in the southern end of the DelMarVa peninsula. Given the proximity of these new reports to the current known source in Wicomico County (Salisbury, MD), they will be included in the forecasts for that general area. A trajectory from Bridgeton, NJ will be included in the forecasts in order to bracket the DelMarVa/southern NJ region. PLEASE NOTE: With disease having been present for at least one month in this region, it is likely that downy mildew is present in other nearby areas, particularly to the north and east of these known sources. Growers concerned about downy mildew should check their plants for signs of disease as soon as possible.
*** Unsettled weather along the eastern Seaboard during this forecast period *** Two main players: a cold front that will move off the mid-Atlantic coast but stall out over the Carolinas and deep South; plus, Tropical Storm Helene, who will likely make landfall in western FL and then move northeastward over the weekend. These two features will combine to bring disease-favorable weather to much of the east coast growing regions. In the Southeast..... Moderate Risk for central and western FL today, Moderate Risk for central and northern FL Friday through Sunday. HIGH RISK for southern and central GA Thursday and Friday, Moderate Risk for southern GA Saturday and Sunday. For the southwest NC / northeast GA sources..... Moderate Risk near the sources Thursday and again on Sunday. HIGH RISK Friday and Saturday for eastern TN, northern GA, southwest NC, and northwest SC as the remnants of the storm move through. For the eastern NC sources..... Strongly Moderate Risk for eastern NC today, Strongly Moderate to HIGH RISK for eastern and central NC Friday and Saturday, Moderate Risk near the sources on Sunday. For the southern NJ / DelMarVa region.... Low Risk Thursday and Friday after this morning's showers. HIGH RISK on Saturday for southern NJ, southeast PA, Delaware, and MD. Moderate Risk near the sources on Sunday. For the OK growers.... Low Risk the next several days, though some localized disease development may occur. In the extended.... the next front will approach from the Midwest early next week. Many growers may be at Moderate Risk on Monday, perhaps greater, if the timing goes as expected.
TK
Images courtesy of Tom Isakeit
Current Sources:
Previous Sources:
Ciudad Mante, Mexico
Colima, Mexico
Houston, Texas
This service is provided by the North Carolina State University departments of Plant Pathology and Marine, Earth, and Atmospheric Sciences.