Crops are tougher than lawns, but they're starting to get stressed
ROSSVILLE — While walking through a patch of sweet corn recently, Toby Brown pulled off an ear of corn and instead of snapping like a crisp stalk of celery, it broke like a rubbery, wimpy carrot.
It's been 20 days since his crop received any measurable rain. And the nights are not providing enough relief from the heat, either.
"The lack of rain and the heat has really affected the patches going through pollination and ear fill," said Brown, whose Lingley Bros. Sweet Corn is sold at farmstands around Vermilion County. As for the earlier-planted corn that should have been ready to pick and sell this week, "without anything — a rain or even dew — the plant is so depleted of moisture it's just not sellable any more," he said.
The Champaign area has received 43-hundredths of an inch of rain in July; the normal for the month is 4.7 inches, according to Illinois State Climatologist Jim Angel.
With much of the month over, it's going to be hard to catch up to that normal level.
What has helped the crops is that the spring was wet, and June wasn't so bad either, with that month's rainfall registering about 4.18 inches, Angel said.
"Everything looked great at the end of June," he said.
It's just the last three weeks that have been tough, particularly on lawns and gardens.
Don't call it a drought, at least not yet, Angel said. It's more like a "suburban drought" or a "bluegrass drought."
"Corn and beans are more robust than our lawns," he said. However, the combination of three weeks without rain and hot temperatures has certainly stressed the crops.
The fields that look green and lush most likely are the ones which were planted earlier in the season and have had a chance to develop strong, deep root systems.
And in recent days some "pop-up showers" have shown up over some small areas.
"If you happen to get one of those, you're blessed," said Dennis Bowman, University of Illinois Extension educator in commercial agricultural crops.
The bright side: "We had a lot of rain this spring and so we had a pretty good supply of soil moisture going into this," Bowman said.
The area was at or above average with soil moisture through the end of June.
"Three weeks of dry weather have dried out the top 6 to 8 inches of soil, but there's still moisture underneath," Angel said.
Added Bowman: "In general, the crop appears to be faring fairly well. But the forecast (for hot weather) seems to keep lengthening."
A break, such as a shower over the weekend, "would really make a big difference," he said.
"The crop needs 2 inches of available soil moisture to get through pollination. If they have a good root system they can access that," Bowman said.
On hot days when there's not enough moisture, the plants direct their energy into keeping cool.
"What happens with corn ... is it starts to regress in its growth. It's putting energy (that is) supposed to be for plant growth, filling out the ear, and it's using that to keep cool," Brown said. "The plants roll up leaves at 9 a.m. That's a self-defense mechanism. They're just sitting there, weathering the storm," he said.
The patches that are hurting are the ones that are chest high or lower, he said.
In hot and dry weather, a few pests — corn leaf aphids in corn plants and spider mites in soybeans — are known to show up and further stress crops by damaging parts of the plants or stealing moisture from them.
But Bowman said he hasn't heard any reports of those pests, yet.
"We're not quite there in full blown agricultural drought, but if we continue for more weeks there could be a problem," Angel said.