Every year you’re likely to see differences in corn yield, depending on where you’re at in a field. This is a function of a large number of factors, including soil type and access to water.
Farm Journal Field Agronomist Ken Ferrie provides reasons to yield check by zone, and an update on one of his fixed-flex ears plots and how the timing hybrids flex also provides considerable yield differentiation.
“As growers are getting settlement sheets, this crop looked bigger in the combine than it does in the elevator,” Ferrie says. “The burned-up hillsides and drowned out replanted areas and frosted areas are putting a real drag on the overall field averages. That’s why we sample by yield zone.”
If you have a field with a 220-yield average, don’t be surprised to have some areas that hit 250, 260 to offset the 180 bu. areas that had something go wrong. Review your yield maps and compare it to soil maps and what you know about those fields.
“You might need variable-rate population to protect those hillsides from burning up while still pushing those other areas to hit that 250 bu.,” Ferrie adds. “Combine operators [also] need to stay on top of header loss. The dry corn wants to shatter and throw ears out of the head.”
He recommends slowing the snapper rollers down and pushing the combine speed a little, as it’s helping some farmers in his area. However, some farmers are reporting they’ve needed to change the drive sprockets on the combine head to slow things down and avoid some header loss.
“Check header loss,” Ferrie says. “Don’t assume because you checked it three weeks ago it’s still good.”
Preliminary fixed-flex plot results
“These are plots where we look closely at how a hybrid flexes,” he explains. “The purpose of our fixed flex plots is trying to learn more about the genetics that we plant and where the yield comes from. Is it kernel count, kernel size or both?”
Ferrie’s team plants hybrids at two populations—22,000 plants per acre and also high populations of 36,000 to 38,000 plants per acre. Low populations give bigger ears, so lower than 22,000 could produce larger ears, but it also means you run the risk of two ears per plant—which throws off the results.
Ferrie and his team use data from the fixed-flex plots to create their hybrid yearbook that will be presented throughout the winter at meetings. This first plot provided interesting data, here are a few notes arranged by hybrid critical growth periods with the following names:
- G hybrids - refers to girth. If the hybrid flexes off rows around from say 18 to 14 when populations increase or they undergo early season stress, this is a G hybrid.
- L-1 hybrids - these are hybrids that flex length in the early season, cob and all. This happens between V6 and tassel.
- L-2 hybrids - length flexes but does so after pollination and through milk fill so it appears as aborted kernels. You could see tip-back in these hybrids, and plots showed kernel loss when populations were pushed in these hybrids.
- D hybrids - kernel depth changes with populations and environmental conditions throughout the last 30 days of grain fill. If it’s a late-planted field, or an area that you know struggles for water in August, these might not be the hybrids to plant.
Learn more details about what Ferrie and his team found this season, and in the fixed-flex plot they recently harvested in this week’s Boots in the Field report:
