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Ignoring These Corn Foliar Diseases May Cost You

April 3, 2020
this agronomic image shows common rust in corn

Corn leaf with common rust

From extreme weather events to increased disease pressure, 2019 challenged you at every turn, and these issues may return this summer. As you develop your corn disease management strategy this season, plan to proactively combat yield-robbing diseases before planting begins. Here’s a reminder of the top corn diseases to watch for:

Southern rust: Southern rust was especially damaging in 2019, with reported yield losses of up to 45%, according to the Crop Protection Network. Wind currents from tropical areas carry the rust spores across states, so scout often and early, especially after storm and wind events that could blow spores into your fields. Look for orange or light brown pustules on the surface of upper leaves while scouting. If not treated early, Southern rust could severely impact yield. University of Georgia researchers say the state has observed yield losses as high as 25 bu/A due to Southern rust.

Common rust: Pustules indicative of common rust are darker than those of Southern rust, and appear on both the upper and lower leaf surfaces. Typically, common rust doesn’t cause widespread damage to corn yields, but applying a fungicide can help prevent a severe infection that could be yield-limiting.

Grey leaf spot (GLS): As you scout for GLS, pay attention to the lower canopy, since the disease starts from the bottom and makes its way to the top. This costly disease can increase rapidly amongst susceptible corn hybrids under warm, humid weather. Keep in mind fields with corn-on-corn rotations and minimal tillage are conducive environments for GLS, due to higher levels of inoculum.

Northern corn leaf blight (NCLB): If you spot long, elliptical lesions on your corn leaves, you may be dealing with NCLB. According to research from the University of Tennessee, NCLB is most damaging in prolonged periods of moisture and temperatures between 64 – 80° F. Plan to take preventive action if you’re planting more susceptible hybrids, if you’re planting corn-on-corn acres or if your field has a history of NCLB.

Jump-start your disease control strategies by scouting for diseases early and adding a long-lasting fungicide to your management plan. To protect corn yields from Southern rust and other diseases, we recommend Trivapro® fungicide. With 3 active ingredients, Trivapro works harder and longer to prevent disease, maximize plant health and boost yield potential.

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