The Richmond Register

September 3, 2013

Reasons to scout corn for stalk strength

By Brandon Sears
Extension Agent

RICHMOND — Excellent yields are expected in many corn fields this growing season.

Along with that good news, however, come concerns over stalk strength.

Plants in many fields have heavy ears, along with shallow roots because of abundant rainfall.

Many of these plants could topple easily as they mature, especially if a late-season storm with high winds blows across the field.

Plus, several extended periods of cloudy weather during grain fill may have increased the risk of stalk weakness in some fields. This is because, when the corn plant is filling grain, if leaves cannot provide the carbohydrate demand of the grain, the plant may “cannibalize” carbohydrates in stalks in order to fill the grain.

Similarly, infectious diseases may play a role in increasing stalk weakness, by depriving the plant of healthy foliage necessary to maintain stalk strength through maturity.

Gray leaf spot is prevalent this year, although levels generally appear to be low to moderate. I have also observed scattered fields with significant damage from northern leaf blight. Given the generally mild, wet weather this season, this isn’t surprising.

Although southern rust has been present in Kentucky for over a month, the generally cool weather experienced in recent weeks has helped suppress disease activity. This disease may still contribute to weakened stalks in some late-planted fields, but in general, it appears we have “escaped” widespread damage from this disease this year, especially if nights remain cool.

Scouting for stalk lodging

Check for stalk weakness by walking the field and pushing plants about 18 inches from vertical. Those that fail to spring back exhibit lodging potential.

If 10-15 percent or more of the field show lodging potential, it may be wise to schedule that field for early harvest, before it is laid down by strong winds.

(Source: Paul Vincelli, UK Extension Plant Pathologist)

Extension Farm Field Day is Thursday

Make plans to attend the Annual Madison County Extension Farm Field Day on Thursday, Sept. 5, starting at 5 p.m. Our host farm this year is Berea College Farm at Hunt Acres in Berea.

Field day topics include: Summer annual cover crops for grazing cattle, pasture poultry and egg production, tilapia, catfish, hybrid bluegill production, shiitake mushroom production, optional tours include swine and goats. These stops will be on a walking tour of the farm, so please prepare accordingly.

A meal will be served with locally sourced meat. Please call us at 623-4072 for meal reservations. Don’t forget to bring your lawn chairs!

Driving Directions to Field Day

Take Exit 77 from Interstate 75, go east on Walnut Meadow Road, turn right on KY 595, traveling past the entrance to Kentucky Artisan Center. Go one half mile; turn right into Berea College Farm (Hunt Acres). Signs will be posted.

Educational programs of the Cooperative Extension Service serve all people regardless of race, color, sex, religion, disability or national origin.