Corn can recover from more stress than many people give it credit for. It depends on the type and timing of the stress. For example, corn can recover from a hailstorm early in the season much more easily than it could if hail hit now.
The Corn Watch ’18 field presents an excellent example of the power of corn to recover from early-season stress, Dave Nanda says. He is the independent crop consultant based in Indianapolis who is scouting the field regularly during the season. The Corn Watch ’18 project is sponsored by Seed Genetics-Direct, Washington Court House, Ohio.
A hailstorm hit the field twice — in the same day! Corn was at about the four-leaf stage. Leaves were tattered and some were twisted as the crop tried to straighten itself out, but for the most part, leaves were still attached to plants.
TATTERED LEAVES: Two hailstorms hit the Corn Watch ’18 field in the same day! Note the tattered leaves. Corn was at the V4 to V5 stage when hail hit.
Nanda visited the field four days after the hail hit, and then 13 days after that. Temperatures were warm, and there was plenty of moisture. Corn grew from the V5 stage on his first visit to V7 on his second visit.
“The change in appearance was dramatic,” Nanda says. “When I returned to the field, it looked very good. You couldn’t really tell it had been hit by hail unless you looked closely and found some plants which still had tattered lower leaves. The new leaves which came out during those 13 days between my visits were dark-green and healthy.”
Growing point safe
The main reason this field recovered so fully was that the growing point was still underground when the hail hit, Nanda says. “It was approaching ground level, but it was still protected by the soil. If the growing point isn’t damaged, plants can usually regrow and produce normally.”
Timing can be everything, and it was in this case, he notes. If the hail had occurred a week later, the growing point would have been exposed. Whether or not growing points would have been damaged would have depended upon the severity of the hailstorm.
TIMING KEY: Four days after hail hit the field, Dave Nanda inspected it. He found the growing point was just at ground level on this plant. It was below the ground and protected when hail hit, so the field was able to fully recover.
Nanda started a demonstration on his second visit in June that he will follow all season. He wants to demonstrate how plants differ in recovery depending upon whether the growing point is damaged or not early in the season. He cut off one plant a couple of inches above the ground; another about 4 inches up, with a couple of leaves remaining; and a third plant about 6 inches from the soil, clearly above the growing point. He repeated this in a second row.
“We will follow what happens and see what plants tell us,” Nanda concludes.