Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu
Barley
We are getting more reports of powdery mildew in ‘Thoroughbred’ barley. This variety is very susceptible and growers have been spraying fungicides to control the disease and protect their yields. Tilt or other labeled triazole fungicides work well along with strobilurin combination products like Quilt, Stratego, etc. Folicur, which is a triazole or sterol-inhibiting fungicide, does not have powdery mildew control on the label for barley or wheat. Folicur (tebuconazole) is now available as a generic as Monsoon, Orius, Embrace, Tebustar and others. When small grains are followed by soybeans there are no plant back restrictions but if you are planting processing or fresh market vegetables be sure to check the label for what can be planted if a fungicide is used in barley or wheat.
Wheat
Disease activity has been light so far. Another sample of wheat spindle streak mosaic virus was received this week. See the article titled Viruses in Winter Wheat in WCU 19:2 for more information. The one control option for wheat spindle streak is planting resistant varieties. Seed company literature and web sites can provide that information. The University of Maryland has some ratings for disease resistance from their variety trial plots. Dr. Arv Graubaskas revised the MD list last December and it is online at: https://sites.udel.edu/weeklycropupdate/files/2011/04/MDWheatDiseaseRatings2010.pdf.