There's a reason it's called the yellow death: stripe rust can spread quickly and kill off huge sections of a wheat field. Even after an effective fungicide application, the yellowing will continue to expand for a few days while the product takes effect.
It's this aggressive spread pattern that has Peter "Wheat Pete" Johnson warning growers not to wait for T3 timing to apply a fungicide if stripe rust is present. Some fields are only five or so days away from early T3 timing and so it might be tempting to wait and hit both diseases at once. That's understandable, Johnson says, but not advisable.
There's also a consideration for product selection and fusarium risk. Growing conditions in Ontario have favoured rust development, but may not favour fusarium, Johnson says, meaning that spraying now to stop the rust then again in the late T3 window could offer maximum disease and DON suppression while saving yield potential.
Related: Wheat Pete's Word, May 28 — A rust alert
