With the struggle to get corn in the ground, it’s likely that farmers are seeing uneven plant growth and some strange colors. Yellow and purple corn crops have been common as soil conditions change. University of Illinois crop sciences professor, Emerson Nafziger, says that purple corn is the result of cool, dry soil, which prohibits root growth and inhibits the taking up of phosphorus.
“The basic cause of corn turning purple is that sugars build up in the plant,” explains Nafziger. “The purple corn problem solves itself. If it hasn’t, why, then I’d certainly start to look around in the roots, look at roots, dig up plants, see what’s going on, but that one doesn’t concern me very much.”
In the case of yellow corn, poor root growth because of wet soil causes nitrogen deficiency. Nafziger suggests that farmers wait until the soil is dry again before adding more nitrogen.
“It’s mostly a problem of the roots not being able to get to the nitrogen that’s there,” he says. “If we get some drying weather and get a good root system going on these crops, they’re going to be able to go down and take up water from deeper depths in the soil, and that water will carry nitrogen up with it. Even if we think the nitrogen is lost, a lot of that that we think is lost is probably deeper in the soil.”AUDIO: Emerson Nafziger (17:00) mp3
Nafziger warns farmers to be cautious before adding nitrogen, as most fields will improve on their own with warmer, drier weather.
As for yields, he says that he doesn’t predict any great losses unless the color doesn’t improve with more favorable weather conditions.