Stalk lodging could be concern this year

August 13, 2019

The Corn Watch ’19 field, planted May 28, was tasseling and pollinating during the last days of July, dark green and clean of foliar disease except for a very few lesions on lower leaves. So far, so good, right?

Closer inspection indicated one factor that could be problematic if fall weather turns wet later, says Dave Nanda, Ph.D., director of genetics for Seed Genetics Direct.

“There were some stalks here and there which were elbowing a bit from the ground up as tasseling and silking commenced,” Nanda said. “I dug up a plant to see if it might be an insect issue. I didn’t find any evidence of corn borer feeding on roots. However, I noticed two things: the overall root mass was smaller than in many previous years and there were fewer brace roots than normal. In fact, plants which were elbowing had very few brace roots.

“Those plants will produce ears. The question is how well and how long those stalks will stand up this fall. There could be lodging issues. Farmers may want to monitor fields closely to determine which ones to harvest first.”

The problem, of course, is that even corn that pollinated in late July could still be carrying a higher moisture content than preferred by late September or early October.

Based on observations and reports by others, scarcity of brace roots and more modest rooting isn’t limited to the Corn Watch ’19 field. These conditions appear to be widespread across brands and hybrids within brands of seed.

Nanda pointed to two potential causes.

“Soil compaction is present in many fields to some degree,” he said. “Farmers didn’t have a choice. Almost anyone you talk to will tell you they had to plant at least some fields which were wetter than they liked. But it was so late, it was either plant when you could or not planted at all.”

However, that isn’t the only cause, Nanda believes.

“It was just so wet in many of these fields that corn roots were adversely affected,” he said. Where the Corn Watch ’19 field is located, it began raining June 15 and rained 10 consecutive days, dropping more than 5 inches of rain during that stretch.

“Soils were saturated and roots need oxygen to develop,” Nanda said. “There is very little oxygen available in saturated soils. Plus, plants had very little incentive to send roots downward when all the moisture they needed, and then some, was near the surface. The effect could well be stalks with shaky foundations this fall.”

The Corn Watch ’19 field is sponsored by Seed Genetics Direct. Reports on the field’s progress are provided all season (#CornWatch19); read the latest Corn Watch ’19 articles here. Stories are written by Tom Bechman.