Trucks and cars aren’t the only things that stall out at times. Corn and soybeans can, too. This past week, a number of farmers told Ken Ferrie their crops are emerged but growth is slow going.
He says two things are contributing to the problem this season in corn – the carbon penalty and ugly corn syndrome. Sometimes, farmers are seeing both simultaneously in the field.
“It’s causing the yellowing and pale green colors that are showing up,” says Ferrie, Farm Journal Field Agronomist and owner of Crop-Tech Inc., near Heyworth, Ill.
The carbon penalty is soil temperature related and carbon load sensitive. “When soil temperatures get above 65 degrees F, the micro population (in the residue) starts to explode. Every 10 degrees, the population doubles, and this explosion sucks up nitrogen, phosphorus and sulfur,” Ferrie explains.
The carbon penalty can happen to any size of corn plant, in any production practice – whether corn on corn, minimum tillage or corn grown in high carbon situations, which is usually most at risk.
“If you didn’t manage for that – say, you’re not doing a good job spreading soybean residue coming out of the back of the combine – and you streak that residue, what you’re going to see now is that corn yellowing over that residue, especially if you planted your corn straight and you cut your beans at a slight angle,” Ferrie says. “Sometimes it makes it easier to see that from the road when you’re going by.”
Mind your handoff. Unlike a carbon penalty, Ugly corn syndrome occurs at a specific growth stage – sometime between V3 and V5 – as the seed roots are handing off their jobs to the first two sets of true crown roots. The problem is not temperature related.
“If anything has messed with the development of those two sets of crown roots, this handoff doesn’t go very well,” Ferrie says. “We’re talking compaction, wheel tracks, sidewall smearing, and herbicide issues – they’re all going to become visible in the stunted plants. They can be just as green as the rest of the field but stunted,” he adds. “The plants will be at the same collar as neighboring plants but not as uniform.”
Ugly corn will look better over time because the bigger plants will outgrow the stunted plants. “But it will delay pollination, and it does have an effect on ear size,” Ferrie says.
Both the carbon penalty and ugly corn syndrome can be managed around.
Fertility is key to getting corn to come out of the carbon penalty and go on to produce a good crop.
“We never walk away from a growing crop,” Ferrie says. “It’s worth the cost of extra nitrogen when you look at today’s corn prices. You don’t want to get caught with your corn turning yellow and staying yellow, because when the crop runs out of energy, it’s game over.”
Soybeans can also be caught in a carbon penalty, which can cause growth to stall at around V3 because of a nitrogen deficiency. Like in corn, the soybean will often turn shades of yellow.
Soybeans will make their own nitrogen but not until about V4 or V5.
Ferrie says he expects stalled soybeans to pop through the carbon penalty in the next week, unless they’re smaller than V3. Those could take 10 days to a couple of weeks to get through the carbon penalty.
“In my mind, a starter application to help push these beans through would be the ticket, but so far, it’s only happened in my mind,” Ferrie notes. “Our starter plots are greener and show less carbon penalty stress, but in the past these plots have not consistently showed us a bump in yield.”
Ferrie shares an update on pest problems in this week’s Boots In The Field podcast, available below:
Ferrie: 3 tips to address ugly corn syndrome, replant decisions and insects
