Firing is moving up the plant in the Crop Watch field. The browning of leaves, starting at the tip of leaves, is the classic symptom of nitrogen deficiency, Dave Nada says. He's a consultant for Seed Consultants, Inc.
Crop Watch 7/20: Disease works its way up the plant in Crop Watch field
Firing first started on a few leaves at the very bottom of the stalk, but it's now moving higher on the plant.
No tests have been done to try to quantify how much N is in the soil. It would also be a good time to use a chlorophyll meter or Green Index tool from Spectrum technologies to get a feel for the amount of N remaining.
The problem is no matter what the readings here, it's likely too late to apply N, even if you could get it on, and expect a result.
Chris Hurt, Purdue University Extension ag economists, says he wonders if N will turn out to be a limiting factor in Indiana, Ohio and Michigan corn yields. He posed that question to Purdue Extension agronomists Bob Nielsen and Jim Camberato, and found they weren't so sure it would be a limiting factor. There may be other things that limit yield first, they implied.
Indeed, disease could limit yields if infection is bad enough. So could weeds. They already have in soybeans according to Bill Johnson, Purdue University Extension weed specialist. The agronomists make the point that it could be a combination of things which pull yields down this summer, especially in the areas hardest hit by water.
Crop Watch 7/17: Spread in pollination between corn hybrids could help this field