It’s time for inspection of fields for SCN

Now is the time to look for soybean cyst nematode on soybean roots. “SCN continues to cause serious soybean yield losses each year in Iowa and throughout the Midwest,” says Greg Tylka, Iowa State University Extension nematologist. “It’s easy to identify SCN infestations in the field during the growing season by checking soybean roots for the presence of SCN females,” he adds.

No matter if you planted a soybean variety that is SCN-resistant, you should still check it. Juveniles of this microscopic worm hatch from eggs in the spring, and then burrow into soybean roots, where they attach and feed. Developing SCN females get progressively larger as they mature, until their fully expanded,
lemon-shaped bodies rupture out of the root and become visible on the root surface.

SCN females are round, white and large enough to see with the unaided eye. It takes four to six weeks or more for the first SCN females of the season to develop sufficiently to rupture out and become apparent on the surface of the roots. Now through the end of July is a prime time to dig roots and check for SCN.

Plants should not be pulled from the soil. Instead, roots should be dug with a shovel or spade, and soil should be carefully removed from the roots. Observing SCN females on roots of susceptible soybean varieties is a quick way to check for the pathogen in a field, says Tylka. More information is at www.soybeancyst.info.

This article published in the July, 2012 edition of WALLACES FARMER.

All rights reserved. Copyright Farm Progress Cos. 2012.