Corn Rust Early This Year!

The strong storm fronts and persistent rain showers have been ideal for common corn rust this year. Common rust, along with northern leaf blight and gray leaf spot, are the most economically important corn leaf diseases in the province. Unlike northern and gray leaf spot, which over-winters in Ontario, common rust spores originate each year from southern US/Mexico. Frequent storm fronts from these areas have deposited spores relatively early this year when compared to the past few seasons.  

Growers need to assess their fields for leaf diseases as we enter the critical tasseling through to silking stage (VT to R1). In most years a fungicide application for disease control is not needed but if you are considering a fungicide application for disease control, take the following into consideration - the susceptibility of the hybrid to disease, yield potential of the field, weather conditions and forecasts, fungicide costs, application method, and crop growth stage. The primary purpose of fungicides is to protect leaves near the ear and above from significant disease. Refer to the OMAFRA Publication 812 "Field Crop Protection Guide" for Registered Products and the diseases they control.

Related Links

• Field Crop Protection Guide