Hybrid Vigor Difference Visible to the Row

Cool, wet weather tests hybrids.

Published on: May 26, 2008

Jim Facemire hosts the Corn Illustrated plots near Edinburgh, Ind. He called mid-week last week and said there was a photo opportunity I couldn’t pass up. And he was right. Two hybrids were planted in the populations study on May 5. Since then, cool, wet weather and several inches of actual rain have beset crops and stopped planters in their tracks in the area., or at least they had as of mid-week last week.

Sure enough, from the road you could pick out the twelve-row strips of one hybrid, and the twelve rows of the other. Corn emerged quicker and more uniform for the first hybrid. It was easy to row it form the road. While corn is emerging for the second hybrid, and while stands will likely be sufficient, emergence is much slower. There will definitely be a difference in how even the corn is once the stand is up.

All of the corn is fairly yellow. But that’s because heat units have been severely lacking over the past two weeks. Corn planted on the same soil type in the next field over a week earlier emerged in 8 days and is taller and greener. Obviously, now we know the time NOT to plant this year in central Indiana, at least, was May 5-6. The flip side, however, is that once the planter rolls again, the calendar and past experience says odds favor lower corn yields than ideal just because of later planting.

Differences in hybrids in emergence and hybrid vigor are not unusual, Dave Nanda assured Facemire. He is consultant for Corn Illustrated and president of Bird Hybrids, LLC, Tiffin, Ohio. Perhaps the results just aren’t always as dramatic as they were last week in the plot.

Time will tell whether the stand for the second hybrid is sufficient to continue the test. Judging form this vantage point, it likely will be. However, uneven emergence may be a complicating factor worth noting. Bob Nielsen, Purdue University corn specialist, demonstrated many years ago that even a couple days difference in emergence between neighboring corn plants can result in yield differences, even if relatively small percentage-wise, at harvest.

The impact of the cool-wet spell in early to mid-May is reminiscent of two years ago, when May 8-9 was the wrong days to plant in the central Corn Belt. The next 10-12 days were similar to this year, although perhaps more severe, especially cooler. Germination was hurt so bad in some fields that year that corn had to be replanted. Fields that were left took a hit on yield in some cases.

Stay tuned to see if the weather shifts soon and the slow-starting hybrid recovers. Heat is also needed to put color back in the hybrid that emerged well and emerged evenly.