Crop Stress is Likely With This Week’s Heat Wave

(Radio Iowa) As temperatures are forecast to climb into the mid to upper 90s all week, the prolonged heat is hard on people, pets — and plants. Angie Rieck Hinz, a field agronomist with Iowa State University Extension and Outreach, says farmers will be watching for signs of crop stress, though she says her region of north-central Iowa is in decent shape.

“I think we’re lucky,” she says. “We got a little bit more rain than other places in the state of Iowa but with that being said, it’s been almost two weeks since we’ve had a significant rain and it sure would be nice to get some moisture with all this hot weather.” Rieck Hinz says much of the corn crop in her area is between R-1 and R-3, from silking to the milk stage.

“There is some corn that’s a little bit later that hasn’t started to tassel yet,” Rieck Hinz says. “So as we go into tasseling this week, that’s my primary concern for that later corn, this hot, dry weather might impact pollination a little bit. The stuff that’s pollinating right now or has been pollinating is already pollinated, so that’s a good sign.” She says the soybeans in north-central Iowa are doing well this summer, though she’s seen a few diseases on the plants, things like bacterial blight and frog-eye leaf spot.

“What I haven’t seen in soybeans is a lot of insect pressure,” Rieck Hinz says. “There’s been Japanese beetles and grasshoppers feeding at field edges, for sure. Nothing significant in terms of damage that I’ve seen, but very few reports of soybean aphids this year. If we turn hot and stay hot and dry, we might see some spider mites come in.” Forecasters say the heat wave will likely last through Friday, and perhaps right into the weekend, with a few outside chances for scattered showers.
(Pat Powers, KQWC, Webster City)