Stripe rust of wheat has been observed in different parts of Illinois within the last week. Although some varieties have very good resistance to stripe rust, there are still several varieties that are susceptible. Stripe rust is able to flourish under the cooler temperatures we’ve had over the last few days. With rain in the forecast in parts of the state over the next few days, favorable conditions for this disease likely will continue.
Although some wheat fields in the state are already past the critical period for applying a fungicide for protection against Fusarium head blight (a.k.a. scab) (beginning flowering up to 6 days after beginning flowering), some fields in the state are just beginning to flower or will within the next week. For the fields that are just beginning to flower or will within the next week, an application of Prosaro or Caramba fungicide should be considered for protection against Fusarium head blight and stripe rust. Multi-state university research has indicated that Prosaro and Caramba are the best products available for managing Fusarium head blight and the associated mycotoxin, deoxynivalenol (DON; a.k.a. vomitoxin). Both of these fungicide products also have efficacy against the stripe rust pathogen.