The recent weather has been conducive to stripe rust. Conditions favorable for disease development and spread include morning dew on the leaves, high winds, and nighttime temperatures in the 40s and 50s. A number of fields in multiple counties have been confirmed (see map below) and many fields have enough stripe rust to be at treatment level or are close to being at that level. If fields have not already been sprayed, data indicates a triazole fungicide will be most effective against active stripe rust and give up to 4 weeks of residual control on small wheat plants. If cool and wet conditions persist into the middle of March, aggressive scouting for stripe rust should continue and another fungicide application will most likely have to be made to MS-S varieties. Please see MP154 at http://www.uaex.edu/publications/pdf/mp154/wheat-foliar-diseases.pdf for recommended control products. Mixed mode of action products, such as those with a strobilurin, will also be effective but may be more expensive. This expense might be better served if disease scouting indicates the need for a fungicide application later in the season to protect the flag leaf from stripe rust on susceptible varieties or from other foliar fungal diseases. Growers should also keep in mind the maximum annual use rates for fungicides applied now. For example, the label for a product with propiconazole as the sole active ingredient allows for a total of 8 fl oz/acre and this could be split into two 4 fl oz/acre applications. An additional application will require a different active ingredient. For additional information on product performance against stripe rust and other diseases of wheat, please see the product efficacy table at http://www.uaex.edu/publications/pdf/mp154/wheat-disease-efficacy.pdf . The greatest opportunity for economic return from a fungicide application will be from fields with a high yield potential. Check back to this blog frequently for updates on stripe rust disease progress.