CENTRAL ILLINOIS (WCIA) — Rolled corn leaves indicate the heat is taking a toll, says Illinois crop physiologist Connor Sible.

“Stu, that is something a lot of people are seeing as they drive down the road and they see the corn rolling,” Sible said. “What we are seeing in our research trials, there are a lot of variables at play as to how much is it rolling and how much is it being affected by that heat. Some of the things we see in our earlier planted crops, in our fields that went in before May 15th, they are bigger plants, bigger plants have a bigger water demand, they are bigger for heat interception, sunlight interception, so they may be taking it a little harder than some of the later planted fields. I am seeing them roll earlier in the day. Some of the later planted stuff that went in after May 15th smaller plants, not using as much water, they are doing a little better in handling the heat and they are not rolling until the late afternoon. And so a lot of variability in when we planted and what stage that crop is at as to how much that heat is going to have an effect.”

Stu: What can we do about this?

“That is a great question,” Sible said. “First thing we look at genetics, some hybrids natural tolerate and regulate their water use better. We’ve got a hybrid study, you can see rolling at different times of the day. Unfortunately we don’t pick our hybrid on heat tolerance, sometimes that might be the luck of the draw. There are some products out there that help the plant mitigate and help the plant regulate its water use. Some of these things like biostimulants, sugars, amino acid products. The challenge there is, you need to put that product out before the heat comes, so its kind of like a preventative, and maybe we can put the band aid on but bleeding has already occurred. So think about when we are going to do these management practices. A lot of times we need to be a little proactive than reactive from the biostimulant perspective. We are fortunate in Central Illinois this next Saturday, Sunday, we’re down to a little cooler temperatures. We got a little bit of a break, that crop had got a chance to recover a little bit. And maybe if we are doing some post emergent herbicide timing, we could put in a sugar or an amino acid and get it kind of ready for the next heat wave. That’s certainly a possibility. But some of that stuff we are done spraying, we’re probably missed that window for this season.”

Connor Sible and colleague Fred Below will be holding a crop physiology field day August 4. Mark your calendar.