Field Scouting Report for May 22: Applying Nitrogen to Wheat Now Will Not Increase Yield; Some Armyworms Spotted This Week

Contact: Jill Scheidt, agronomy specialist
Tel: (417) 682-3579
E-mail: scheidtjk@missouri.edu

LAMAR, Mo. –Jill Scheidt, agronomy specialist with University of Missouri Extension in Barton County, scouted area fields on May 22 to prepare this week’s field scouting report.

According to Peter Scharf, MU Extension state fertility specialist, at this point producers who applied anhydrous on corn ground in January or February have lost no more than 10-20 percent of the nitrogen applied. Dry fertilizer and earlier applied fertilizer have a greater risk for loss.

By going to the website and typing “Nitrogen Watch” into the search engine producers track rainfall and possible nitrogen loss by using the “Nitrogen Watch” web tool.

“It is too late to apply nitrogen to the wheat once 2 nodes are present on the stem. Research has shown that applying nitrogen in the fall then applying nitrogen past the boot stage will not increase yield,” said Scheidt. “It is not economical to apply nitrogen once wheat is in the boot stage because wheat will not efficiently use nitrogen and the increase that could be seen in wheat will not cover the cost of the nitrogen application.”

No diseases were seen this week in wheat. According to Scheidt, weather conditions are still favorable for fusarium head blight. Fungicides do not control head blight, fungicides can only suppress head blight. Fungicides that suppress fusarium should be applied at or during flowering. Remember to read the label for the appropriate timing of fungicide application.

ARMY WORMS

Armyworms were seen in wheat fields around Lamar, just under threshold level. Threshold level for armyworms is 6 per foot. Mustang Max or Hero is recommended to control armyworms. To scout for armyworms bang wheat heads together, then look on the ground for small to medium sized worms.

Armyworm feeding was also seen in corn, but not at threshold level. Armyworms begin feeding in the whorl to the outside of the whorl. Leaves appear as if they had been shot by a shot gun.

MORE INFORMATION

Helpful articles on funguses and fungicide ratings, late corn planting and burndown procedures can be found on the website at extension.missouri.edu or by calling the nearest county extension center.

The weekly field scouting report is sponsored by University of Missouri Extension and Barton County Extension.

For more information on this scouting report, or to learn how you can receive it a week earlier by telephone, contact the MU Extension Center in Barton County at (417) 682-3579.