Dr. Lenny Wells –
An 80/20 or 90/10 surfactant can be helpful in providing better scab control when used with DMI fungicides (Enable, Tebuconazole, Orbit, Propimax, Bumper), strobilurins (Abound, Sovran, etc.), and combination products like Absolute, Quadris Top, and Quilt. But you will likely see no benefit to adding a surfactant unless there is significant scab pressure.
Thankfully, from the standpoint of scab management, its been a much drier spring so far. As a result, we haven’t really had any serious scab pressure yet. So, a surfactant would not really be justified at this point until we see the development of more consistent rainfall patterns. If the rain returns, a surfactant will help. Growers are aware that every addition to that spray tank runs up the cost of production and understandably, many are wary following the previous 2 wet years. But, bear in mind scab won’t develop without the right weather conditions. So, save money while you can because the weather can change at any time. If conditions become more favorable for scab and the addition of a surfactant with fungicide sprays is needed, check the label of the surfactant used for the appropriate rate.