Variable. It's not just a math term, but almost a way of life for farmers. There are constant variables — from those you can control like seeding and fertilizer placement — to those out of your control like weather and crop infestations.

Corn & Soybean Digest would like to help ease one variable for you this spring: corn diseases and pests. Information from Extension publications and specialists should help you be prepared for what could show up in your corn fields this summer.

“One newer thing we tried to stay on top of in 2009 was Western bean cutworm,” says Ron Hammond, entomology professor, Ohio State University. “While finding no infestations, we caught more adults in 2009 in Ohio and will plan on keeping a close watch on them this year.”

To keep pests under control, Hammond suggests scouting, sampling and treating when necessary. So does Iowa State University Entomologist Erin Hodgson.

“Insecticidal seed treatments may help regulate early season pests,” she says. “But for mid- and late-season insects, growers will have to make timely foliar applications to protect yield. Sampling on a regular basis will help prevent economic damage.”

SCOUTING TO PREVENT damage will also help when it comes to corn diseases.

“Many pathologists nationwide are concerned about Southern rust, a rust disease distinct from common rust, which is most familiar in the Corn Belt,” says Paul Vincelli, University of Kentucky Extension plant pathologist. “In Kentucky, we have not seen an outbreak like this in 20 years. It's an emerging disease we need to watch out for in 2010.”

Vincelli recommends scouting fields and contacting your local county agent if you need help determining the difference between common rust and Southern rust, which can have a more devastating effect.

The insects and diseases here are just a sampling of what regional entomologists and pathologists expect. Of course, the big variable in what actually shows up in your fields seems to be the weather. No matter what's expected in your fields, however, it's important to scout and sample and keep an eye on your crops all season to stay on top of the infestation variables.

For specifics about the insects and diseases on the map, please go to www.cornandsoybeandigest.com/corn/pests or /corn/diseases.