David Hula Shares Risk Management Strategy to Address Corn Pollination Challenges

As corn growers are evaluating pollination, more reports of problems resulting from the “overly tight tassel wrap” phenomenon are trickling in from farmers and agronomists, with pictures and commentary now posted to social media and various websites.

Reigning world corn yield record holder David Hula says he is seeing the issue in some Virginia fields and also hearing reports on the problem from fellow corn growers in states along the Eastern Seaboard.

“Some farmers have been walking fields thinking they’re getting plenty of rain and are going to knock it out of the yield park with this crop, but we’ve got pollination problems,” reports Hula, who’s based near Charles City, Va. “I walked a bunch of fields this past weekend to make sure I still want the plane (to fly inputs) on certain fields.” he adds.

“This isn’t happening just in Virginia, I know it’s happening in the mid-Atlantic… in Delaware and Maryland and the Carolinas. I don’t know how far West this goes…” he told Randy Dowdy on their new episode of Breaking Barriers with R&D podcast.

The Culmination Of A Perfect Storm?
At this point, no one has a clear handle on how extensive the pollination problem is across the Corn Belt.

Farm Journal Field Agronomist Ken Ferrie says he is seeing the issue occur in parts of Illinois as corn reaches about V6 or V7 up through tassel – as the crop goes through rapid growth.

“This corn is growing like crazy, putting on an inch and a half of root a day, putting on a node every three days, that type of thing. The tassel can get wrapped really tight, and usually it’s triggered by some type of stress. Your hope is that that tassel gets out of the tight wrap before pollination starts, and usually it does. But this year, we have some hybrids that are really struggling to get that done. Unfortunately, the tassels are still wrapped tight, and the silks are out and they’re waiting for that pollen.”

Mark Licht, Extension cropping systems specialist at Iowa State University, reports tassels shedding pollen while still wrapped in the flag leaf is an uncommon occurrence in Iowa and across the Corn Belt and that he has only seen it once in the past 20 or so years.

In an online article, Licht says the problem does not seem to be brand-specific but does appear to be hybrid-specific.

“We believe this may be a form of rapid growth syndrome occurring at the end of the vegetative stages, likely triggered by a combination of high temperatures, ample moisture and non-limiting nutrient availability,” he writes.

Ferrie says he has seen the issue in previous years and thinks it might be influenced partly by wide swings in temperature during a 24-hour period. “You’re up in that 85- to 90-degree range during the day, and then you crash into the 50s at night. That seems to trigger this.”

Licht is trying to get an idea of how widespread the problem is in corn. Farmers in Iowa and across the country can help him gain insights on this issue by completing his wrapped tassel questionnaire.

Address Silk Clippers In Compromised Corn Crops
Unfortunately, there is no counter measure farmers can take to correct or improve poor pollination.

One step Ferrie encourages impacted growers to take is to look for feeding from silk clipping pests. Japanese beetle and corn rootworm beetle species are two of the key pests he is seeing in fields feeding on silks now.

“When you’re under this much pressure to get corn pollinated, if you’ve got any beetle silk clipping going on on top of this problem, you may have to go in there and do a preemptive strike,” Ferrie says. “Clean up your silk clippers if they’re there. Aphids can be part of the problem, as well.”

Ferrie offers more insights from his perspective on what is contributing to the problem in his discussion with Farm Journal’s Tyne Morgan and Clinton Griffiths in their latest podcast.

A Good Way To Minimize Risk Next Season
Hula believes in minimizing production risks with strategic use of his corn planter, and he encourages other growers to do the same. His objective: plant hybrids with similar Comparative Relative Maturities (CRMs) – also sometimes referred to as Relative Maturity or RM – but with different flowering dates.

This is information he can usually access via seed company product catalogs or a company representative.

“Between companies, some of their CRM models or numbers are a little different, so you have to take that into account,” Hula says.

Assessing Growing Degree Units (GDUs) in the flowering process also plays a role in Hula’s hybrid selection methods.

“If I’m using the same genetic package from the same company, we’ll look for a six-day range of pollination,” he notes. “And if I’m changing companies, then we just try to find when they’re silking and come up with their best strategy. I want similar CRMs, but I’ll go with as much as two CRM differences.”

Hula usually splits his 16-row planter with two hybrids – eight rows of one hybrid and eight rows of a second hybrid – to go across the field. This year, he used three hybrids at a time in the planter.

“That helps spread out the risk, as we find some maturities are having pollination problems and others aren’t,” Hula says.
Ferrie explains that if the grower uses at least two different hybrids in the planter and the hybrids sync up at silking, growers are able to mitigate risk, “because the one hybrid pollinated the other one for you,” he says.

Hula goes into more detail on how he uses hybrid selection to mitigate production risks in Breaking Barriers With R&D. Watch it on YouTube: Breaking Barriers with R&D: Split the Planter, Split the Risk