Watch for Southern Rust

Jul 24, 2020
Megan Hasenour | Marketing Communications Manager

Southern Rust

It’s important for you to be aware of corn disease issues coming into our area. A few weeks ago when corn began tasseling it was hot, dry in a lot of areas. Within the last week we have seen a weather pattern change. We have received ample rain, a vast amount of humidity daily and a fair amount of dew and fog in the morning keeping the crop canopy wet. These factors provide ideal conditions for disease pressure. A large and potentially detrimental threat to our crop that could arise with these conditions is Southern Rust.

Southern Rust is aggressive fungal pathogens that favor high temperatures and relatively high humidity. Yield impact depends on the timing of the infection, the amount of the leaf area damaged, and the location of damaged leaves on the plant.  Southern Rust produces raised orange to tan spores on the top or upper part of the leaf that can be wiped off. The Southern Rust fungus uses the plant’s nutrients for growth and reproduction, which affects grain fill and reduces yields.

There is confirmed Southern Rust near our cooperative footprint and it’s a good idea to keep an eye out for it in your fields. We’re sharing a link where you can see an updated map of where confirmed cases of Southern Rust are located in the US. Up to date Southern Rust Map

We encourage you to get out in your fields and look up at the canopy. If you see light green spots, these are spores. Spores are start of disease. You don't want to wait until disease is already in your field, you want to apply fungicide before the disease becomes unmanageable and stop the spores in their tracks. Think of if this way, you don't spray weeds when they get too tall, you spray them when they are controllable. A fungicide application will prevent the spores to become lesion. When lesions are formed that plant tissue is dead. 

Please contact your local Superior Ag Agronomist to schedule a fungicide application today!