Continued Extreme Heat Could Damage Corn, Soybeans

As days with extreme heat coupled with drought conditions have dominated the weather statewide in recent weeks, growers have begun to ask themselves just how hot is too hot for corn and soybeans?

While corn originated as a tropical grass and can tolerate exposures to temperature extremes as high as 112° for brief periods, the optimal daytime temperatures for corn typically range between 77° and 91°, said Peter Thomison, an Ohio State University Extension agronomist.

When temperatures rise above 95°, corn growth decreases, he said.

“When temperatures hit between 93° to 98° for four days or more, you could start to experience yield losses in corn, but it also depends on the amount of moisture in the soil,” Thomison said. “It’s hard to separate high temperature effects on corn from effects of drought on corn because the two usually go hand in hand.

“It’s really hit or miss right now because of very localized drought conditions, where you have a lot of people who are suffering while others may not be experiencing conditions that are as bad. This is a very critical period for corn.”

Growers are extremely watchful of the weather now, considering that the majority of Ohio except for small portions of some counties near the Kentucky, West Virginia and Pennsylvania borders is experiencing moderate drought, with areas near the Indiana and Michigan borders experiencing severe drought as of July 31, according to the most recent U.S. Drought Monitor.

And the weather outlook for the first couple of weeks of August call for above-normal temperatures, with periods of high heat throughout the state and below-normal rainfall in some places, and the potential for near-normal amounts of rainfall in other areas, according to Jim Noel of the National Weather Service.

Noel, whose weather updates are featured in the OSU Agronomics Crop Team’s weekly C.O.R.N. (Crop Observation and Recommendation Network) Newsletter, said rainfall will average 0.25 to 1.00 inches through Aug. 5, with the normal range for the period at 0.75 to 1.00 inches.

The outlook for August 6 to August 12 calls for temperatures mostly between 85° to 95°, with lows ranging from 65° to 72°, he said. Rainfall will average 0.25 to 0.50 inches, which is below normal for the period, Noel said.

Soybeans, on the other hand, are a more temperate leguminous plant with an ideal daytime temperature of 85°, said Laura Lindsey, an assistant professor of horticulture and crop science at Ohio State. When air temperatures exceed 85°, soybeans can experience heat stress regardless of reproductive stage, she said.

“Soybean yield is affected by three things, the number of pods per plant, the number of seeds per pod, and how big the seeds are,” she said. “When soybeans experience heat stress, yield reductions can begin to occur, especially when soil moisture is limiting.

“Temperatures over 85° can result in a decreased number of pods, while temperatures above 99° can severely limit pod formation.”

Hot summer nights can also impact corn yields, Thomison said. Corn grown when night temperatures are in the mid-60s out-yields corn grown at nighttime temperatures in the mid-80s, he said.

“With high nighttime temperatures, more of the sugars produced by photosynthesis during the day are lost with less available to fill developing kernels or seeds, thereby lowering potential grain yield,” Thomison said.

Conversely, soybeans aren’t as susceptible as corn to yield impacts by high nighttime temperatures, Lindsey said. This is because during the day, soybean plants accumulate starch in their leaves, which is broken down and exported from their leaves at night.

“When nights are cool, the amount of starch exported is reduced, resulting in high leaf starch the following day which can disrupt photosynthesis,” she said.

But extremely high nighttime temperatures, above 85°, could also cause a noticeable reduction in soybean yields as well, Lindsey said.

Topics:

Leave a Reply

Crop Inputs Stories

Syngenta Seedcare Institute
Seed/BiotechSyngenta Opens New North America Seedcare Institute In Stanton, MN
September 23, 2016
Syngenta unveiled its new Seedcare Institute in Stanton, MN, during a recent grand opening celebration. More than 150 industry leaders, Read More
Crop InputsJim Loar Promoted To President And CEO Of Cool Planet
September 22, 2016
In a move that reflects and reinforces the company’s commitment to the agricultural market, the Cool Planet board of directors Read More
Crop InputsMonsanto, Bayer Officials Defend Proposed $66 Billion Merger
September 21, 2016
Top officials for Monsanto and Bayer defended their proposed $66 billion merger before skeptical senators on Tuesday, insisting that the Read More
Corn
Crop InputsEPA Settles With Syngenta For Alleged Multi-Regional Pesticide Violations
September 19, 2016
The U.S. EPA has announced a multi-region settlement with Syngenta Crop Protection, LLC (Syngenta) in Greensboro, NC, for alleged violations of Read More
Trending Articles
Corn Field
Eric SfiligojFacing Ag Industry Challenges
September 26, 2016
At the 2016 annual Mid America CropLife Association (MACA) meeting in September, a pair of crop protection company representatives discussed Read More
Bayer Monsanto
Crop InputsBayer-Monsanto Mega-Merger: 6 Things You Need To Know
September 14, 2016
Mega mergers have become almost routine in the agricultural industry. Right on the heels of Monday’s news that fertilizer giants Potash Read More
Potash Corp Agrium
Crop InputsAgrium, Potash Corp To Merge To Create $36 Billion Company
September 12, 2016
Canada’s Agrium Inc. and Potash Corp of Saskatchewan Inc. have agreed to combine in a deal that would create a Read More
Osage Co-op Elevator Osage, IA Finished Building
OpinionAre We Crazy?
September 8, 2016
At some point in the first few months of my employment here at CropLife® magazine, I started getting curious about Read More
ManagementMAGIE 2016 Highlights and Deere Anti-Trust
September 1, 2016
CropLife Editor Eric Sfiligoj discusses the recent Midwest AG Industries Exposition and the Department of Justice’s objection to John Deere Read More
ASMARK 2016 Retailers Live! Tour - CPS
CropLife 100CPS Acquires Texas Retail Operation
August 23, 2016
Crop Production Services (CPS) has acquired the assets of Larry’s Chemical and Spray, Inc., for an undisclosed amount in an Read More
Latest News
Young Corn Field
StewardshipStudy: Ohio Farmers Doing ‘A Good Job Of Managing…
September 27, 2016
Leaders from Ohio’s largest grain farming organizations announced today that Ohio farmers are doing their part in effectively managing phosphorus Read More
Growmark FS Outlet
Industry NewsGROWMARK To Purchase Suncor’s Share Of UPI
September 26, 2016
GROWMARK and Suncor have reached an agreement in which GROWMARK will purchase Suncor’s 50% interest in UPI, Inc. in Ontario, Read More
Corn Field
Eric SfiligojFacing Ag Industry Challenges
September 26, 2016
At the 2016 annual Mid America CropLife Association (MACA) meeting in September, a pair of crop protection company representatives discussed Read More
Syngenta Seedcare Institute
Seed/BiotechSyngenta Opens New North America Seedcare Institute In …
September 23, 2016
Syngenta unveiled its new Seedcare Institute in Stanton, MN, during a recent grand opening celebration. More than 150 industry leaders, Read More
StewardshipMonsanto Invests $1.6 Million In System To Quantify Gre…
September 23, 2016
The USDA – Natural Resources Conservation Service (USDA-NRCS) recently awarded the National Corn Growers Association (NCGA) and its Soil Health Read More
Pipe rack
LegislationCourt Sides With Ag Retailers On PSM
September 23, 2016
The D.C. Court of Appeals has ruled the Occupational Safety and Health Administration violated the Occupational Safety and Health Act when Read More
ManagementPacific Coast Fertilizer Announces Interest In Longview…
September 22, 2016
Pacific Coast Fertilizer LP (PCF) announced at the Cowlitz Economic Development Council board of directors meeting its interest in developing Read More
Young corn plants in soil
UncategorizedCool Planet Raises Additional $9 Million To Commerciali…
September 22, 2016
Cool Planet has announced the first close of a new financing round to commercialize the company’s Cool Terra Engineered Biocarbon Read More
Crop InputsJim Loar Promoted To President And CEO Of Cool Planet
September 22, 2016
In a move that reflects and reinforces the company’s commitment to the agricultural market, the Cool Planet board of directors Read More
BlendersNorth Dakota Coop Debuts Dry Fertilizer Plant
September 22, 2016
North Central Grain Cooperative has begun operations at a new dry fertilizer plant at its Rolla, ND, site. It is Read More
Crop InputsMonsanto, Bayer Officials Defend Proposed $66 Billion M…
September 21, 2016
Top officials for Monsanto and Bayer defended their proposed $66 billion merger before skeptical senators on Tuesday, insisting that the Read More
ManagementUpcoming Shows & Recent Events
September 19, 2016
Editors Paul Schrimpf and Eric Sfiligoj talk about upcoming trade shows and events and review the Mid America CropLife Association Read More
Industry NewsVerdesian Life Sciences Appoints New CEO
September 19, 2016
Verdesian Life Sciences, a plant health and nutrition company, today announced that its board of directors has named Kenneth M. Avery Read More
Corn
Crop InputsEPA Settles With Syngenta For Alleged Multi-Regional Pe…
September 19, 2016
The U.S. EPA has announced a multi-region settlement with Syngenta Crop Protection, LLC (Syngenta) in Greensboro, NC, for alleged violations of Read More
ManagementMerger Mania
September 16, 2016
Editors Paul Schrimpf and Eric Sfiligoj discuss this week’s mega-ag mergers of Bayer and Monsanto and Potash and Agrium. Read More
Monsanto sign
Crop InputsMonsanto Ends Up Being A Bargain For Bayer
September 16, 2016
History will say Bayer got a bargain in its $66 billion purchase of Monsanto, writes David Nicklaus, St. Louis Post-Dispatch. The Read More
Greg Musson, Gar Tootelian
CropLife 100California Ag Retailer Steps Up To Feed Families Affect…
September 16, 2016
GAR Tootelian, Inc. (GAR) in Reedley, CA, is challenging the Central Valley to help raise enough money and provide 525,000 meals Read More
Crop InputsBayer, Monsanto CEOs Discuss Merger
September 15, 2016
Werner Baumann, Bayer CEO, and Hugh Grant, Monsanto CEO, discuss why they decided to merge their companies. Read More