ISSUE 2   May 21, 2009


The Plant Pathology Department at North Dakota State University will again be providing the potato blightline service at no charge to the potato industry of North Dakota and western Minnesota in 2009. This will be the fifteenth year that this service has been provided and sponsored by Syngenta Crop Protection. The hotline uses local weather data collected from weather stations throughout our area to forecast the occurrence and spread of late blight in fifteen non-irrigated and twelve irrigated production areas in ND and western MN. The data is processed by the North Dakota Agricultural Weather Network (NDAWN) and analyzed by a computer program (WISDOM) to forecast when conditions are favorable for late blight to occur.

The forecast information is used by plant pathologists Gary Secor and Neil Gudmestad to make late blight management and fungicide recommendations. The recommendations are made Monday, Wednesday and Friday of each week during the growing season. The first late blight hotline will be Monday June 1st, and it is anticipated that the hotline will continue through mid-September depending on disease pressure. The hotline will also be used to confirm reported late blight sightings and serve as clearing house for national late blight information. In addition to late blight forecasting, the hotline also provides cumulative P-values for early blight disease forecasting and management recommendations. Finally, it serves to alert growers of other disease and insect news, as well as posting messages of general interest such as potato field day dates.

The hotline recommendations can be accessed by phone or website. The toll free phone number is 888 482-7286.

The NDAWN website for potato disease forecasting contains colored maps of ND to pictorially illustrate the late blight severity values (both two day and seasonal), favorable day values and P-day values for early blight throughout ND. That site is: Go to applications and then click the potatoes drop down box.

Growers and scouts are encouraged to send suspect late blight samples to us for positive identification. Late blight is a community disease and proper identification and prompt notification is important. Leaf samples should be placed in a slightly inflated zip-lock plastic bag without a wet towel and sent to:

Gary Secor
Plant Pathology
NDSU Dept 7660
PO Box 6050, Walster Hall 306
Fargo, ND 58108-6050

Our phone number is 701 231-8362 and email address is We look forward to a successful potato year.



Each year, soybean rust is a looming threat to the United States soybean crop. However, winter temperatures will kill the pathogen in most of the U.S., surviving only in the gulf coast states. For soybean rust to cause problems to North Dakota growers, several things have to happen.

  1. Soybean rust must successfully survive the winter
  2. The disease must develop in the South early in the season
  3. Conditions must be favorable for the disease to spread and develop to the north.
  4. Soybean rust must reach North Dakota fields before R6 (at R6 no yield is lost).

Plant pathologists across the United States are monitoring the development and spread of the disease using sentinel plots and mobile scouting. A sentinel plot is simply an area in a soybean field that is scouted weekly and mobile scouting is when we strategically scout fields in certain geographical areas, but are not restricted to any one field (i.e. three fields in Richland county). The North Dakota Soybean Council and the North Central Soybean Research Program are supporting the scouting of eight sentinel plots in the southeastern part of North Dakota and at least five mobile plots in the Northern valley. The information is put on the website

Currently, soybean rust is developing in gulf coast states.

Soybean rust

Red indicates counties in which soybean rust was scouted and found, green indicates counties in which soybean rust was scouted for and NOT found. North Dakota scouting will begin when this years crop is up.

Sam Markell
Extension Plant Pathologist

NDSU Crop and Pest Report Home buttonTop of Page buttonTable of Contents buttonPrevious buttonNext button