Powdery Mildew: The winter wheat variety ‘Decade’ is supporting considerable powdery mildew in the lower canopy, as observed in many winter wheat locations across the state. This variety appears to be particularly susceptible to this disease. Propiconazole-containing fungicides (such as Tilt, Bumper, etc.) are very effective in controlling powdery mildew, but we have no data in North Dakota on economic losses from this disease in wheat.
Stripe Rust: Stripe rust has been reported in winter wheat near Peak, North Dakota in the Ducks Unlimited plots, and was also observed in ‘Ideal’ winter wheat at Prosper, but was extremely hard to find. No stripe rust was seen in winter wheat at Forman or near Lisbon, in southeast ND, on June 4th. Stripe rust observations were made in areas that have had more rainfall than occurred in the past week at Forman or Prosper. With scattered thunderstorms predicted for the week and weekend, growers will have to watch their crops closely for any possible stripe rust development. Warmer temperatures occurring this week are not favorable for stripe rust sporulation.
Disease Forecasting: The risk of Fusarium head blight infection and leaf diseases has diminished in the last few days in North Dakota, with the current warm, dry conditions. Winter wheat fields in southern counties are in flowering or even have pushed through the flowering period, and for the most part look quite good. Some advanced spring wheat fields also are approaching flowering, while others across the state are in the 5-6 leaf stage. Growers, agronomists and consultants need to keep looking at the small grain disease forecasting site (www.ag.ndsu.nodak/cropdisease) for any changes in disease risk as the week progresses.