Some of the common diseases that affect sugarbeet include Cercospora leaf spot, Fusarium, Rhizomania, and Rhizoctonia crown and root rot.
Weather in the state has generally been conducive to rust infection and spread, and I have received a good number of questions about rusts on several crops. Below is general information about rusts, followed by specific information to several rust diseases that you may be thinking about. I am not discussing cereal rusts because much of those crops are mature.
Wet field conditions in April delayed sugarbeet planting by about two weeks. Typically, all things being equal, later plantings result in lower yields than earlier plantings.
I am receiving many inquiries about white mold, particularly from dry edible bean growers. In my opinion, the statewide (or region-wide) risk of white mold is somewhat more complicated than it has been in recent years, for two reasons.
Moderate to high risk of Fusarium head blight infection (FHB) is still present (July 30th) for susceptible wheat and durum varieties in northern and northwest counties in North Dakota.
The NDSU disease forecasting site (www.ag.ndsu.edu/cropdisease) for small grains indicates continued risk for leaf diseases and FHB (scab) along the northern tier of counties in ND.
Cercospora leaf spot (Figure 1) is the most damaging leaf disease of sugarbeet in North Dakota and Minnesota.
The NDSU small grain disease forecasting information indicates some continued risk of tan spot infection, as of July 16, and moderate risk of FHB (head scab) for susceptible varieties across many areas of the state.
Fusarium yellows was first observed very early at the American Crystal Coded Research trial at the Moorhead, MN research site in June. There are several commercial fields in the Crookston and Moorhead Factory Districts that have been diagnosed with severe Fusarium yellows.
Spotted Bacterial Blight and Brown spot (Figure 1) in recent scouting’s of soybean fields across Ward and Renville counties. These two diseases generally look alike and hard to differentiate with naked eye.
White mold is a concern in most broadleaf crops, but only once they enter bloom and under favorable environmental conditions.
Tilt fungicide now has a new PHI for wheat and barley. The previous label said “Do not apply after Feekes 10.5; the new label says “Do not apply after Feekes 10.54.”
Several people have brought to my attention that the NDSU Small Grain Disease Forecasting site (www.ag.ndsu.edu/cropdisease/) is not opening up properly for them, not giving them access to all the NDAWN stations and growth stage choices.
The national Fusarium head blight prediction center (www.wheatscab.psu.edu/) has a feature that allows you to look at the predicted risk for 24, 48 and 72 hours in the future.
The NDSU small grain disease forecasting site (www.ag.ndsu.edu/cropdisease) indicates that most NDAWN locations are indicating risk of leaf disease, but as of July 9, very low risk of Fusarium head blight (FHB).
Dr. Tom Gulya, USDA-ARS, is conducting a survey to monitor the downy mildew pathogen for race changes and fungicide sensitivity.
Downy mildew is caused by a soil borne pathogen that can survive for many years in the soil. When frequent rains occur after planting, the pathogen produces swimming spores (zoospores) that infect roots and cause a systemic infection.
As canola enters bloom, the crop becomes susceptible to white mold. Fungicides are available that can help manage the disease, but the more important decision is whether or not the environment is favorable for infection and disease development.
Risk of tan spot continues in some NDAWN locations in the northern tier of counties. However, the risk of FHB has diminished, due to warmer temperatures and dry conditions occurring now and predicted for the next few days.
With substantial rains last Thursday through the weekend across much of the state, many NDAWN locations are showing risk of tan spot again.