March is an important month for wheat disease development in Kansas. This statement may surprise some of you, because the wheat is only just greening up in some areas of the state.
As it turns out, February and March are important because we often receive our first reports of disease activity from states to our south. This is particularly relevant for the rust diseases, which often survive the winter in these southern climates.
So far this year, there are several reports of rust developing in Texas, Arkansas, Louisiana, and Mississippi. Stripe rust has been observed in all four states and appears to be spreading beyond the initial foci of infection. Leaf rust has been reported in Texas but not the other states.
The reports of stripe rust and leaf rust from Texas are the most important for us, because weather systems often transport the rust spores from these regions into Oklahoma and Kansas. Varieties such as Everest, Armour, and TAM 111 are being affected in Texas this year. This is similar to what was observed in 2012 and there are no reports of new races of stripe rust to date.
Bob Hunger, wheat disease specialist for Oklahoma State University, is reporting no finds of rust in Oklahoma as of March 21. Growers in Kansas should be monitoring the situation in Texas and Oklahoma. If the disease continues to develop in Texas or is reported in Oklahoma, we will need to evaluate the need for fungicides to suppress rust development in fields planted to susceptible varieties.