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
Crop InputsPlatform Specialty Products To Acquire Arysta LifeScience
October 20, 2014
Once the acquisition is complete, Platform Specialty Products will combine Arysta LifeScience with previously acquired companies Agriphar and Chemtura Crop Solutions. Read More
MicronutrientsMicronutrients Going Macro
September 9, 2014
Between 2014’s fantastic growing conditions and a heightened awareness on plant nutrition, the major players in micronutrients are gearing up for another big year. Read More
FertilizerFall Fertility 2014: Forecasting Fertilizer Use
September 7, 2014
Great crops this year have tapped the soil, and fall work is definitely called for, but how challenging will that get? Read More
FungicidesSudden Death Syndrome, Brown Stem Rot Reported In Indiana Soybeans
September 3, 2014
Farmers and retailers should be watching for symptoms of these two diseases over the next few weeks as they are best managed through preventative methods. Read More
Top 100 Articles
CropLife 100Pinnacle Agriculture Acquires Minnesota Retailer
April 14, 2015
Pinnacle Agriculture Holdings, LLC, ranked No. 6 on the CropLife 100,  has successfully acquired Liebl Ag, LLC in Ada, MN.  Read More
CropLife 100CHS, Aurora Cooperative Complete Fertilizer Storage, Grain Shuttle Loading Facility
April 13, 2015
CHS Inc., the nation’s leading cooperative and ranked No. 5 on the CropLife 100, and Aurora Cooperative (ranked No. 21) Read More
CropLife 100GROWMARK Acquires Missouri Refined Fuels Terminal
April 2, 2015
Bloomington, IL-based GROWMARK and Magellan Pipeline Co. have entered into an agreement in which GROWMARK will acquire the refined fuels Read More
CropLife 100Wilbur-Ellis Acquires South Dakota Retailer
April 2, 2015
Wilbur-Ellis Co.’s Agribusiness Division, a recognized leader in precision agriculture technology and the distribution and marketing of plant protection, seed Read More
CropLife 100The McGregor Co. Closes Smith-Kem Acquisition
April 2, 2015
The McGregor Co. — ranked No. 16 on the CropLife 100 list of largest U.S. ag retailers — has completed Read More
CropLife 100BRANDT Commemorates National Ag Day
March 20, 2015
The Illinois agriculture community gathered at BRANDT global headquarters on March 18 to celebrate National Ag Day behind this year's theme Sustaining Future Generations. Read More
Latest News
FertilizerSimplot’s Gal-XeONE Technology Moves West
April 27, 2015
The J.R. Simplot Co. remains committed to creating customer value through technology. In 2013, Simplot purchased the Gal-XeONE controlled release Read More
Eric SfiligojThe Need To Defend Production Agriculture
April 27, 2015
Last week, I spent the better part of my time on the road visiting with ag retailers and market suppliers Read More
FertilizerStarter Fertilizers Show Value In Stressful Spring Cond…
April 27, 2015
From wet, cold conditions in the eastern Corn Belt to excessively dry, cool soils in the Plains states, spring field Read More
StewardshipTFI Announces Renewed Financial Commitment To Fertilize…
April 24, 2015
Today, The Fertilizer Institute’s (TFI) President Chris Jahn announced that TFI and over 100 partners will more than double existing Read More
Industry NewsMACA Names New Ambassador Coordinator
April 23, 2015
The Mid America CropLife Association (MACA) has named Michelle Kilper as its new Ambassador Coordinator. Michelle is a graduate of Read More
ManagementAg Retailer’s Role In Local Policy Making; Raising The …
April 23, 2015
CropLife’s Paul Schrimpf and Eric Sfiligoj review their recent travels, precision ag efforts in Washington, DC, and the role of Read More
TMX-2050 In-Cab Display Launch Run Screen
Precision AgIn-Cab Computing 2015: Connectivity, Compatibility Take…
April 23, 2015
In terms of in-cab computing solutions for the agriculture market, companies like Case IH, Topcon, Trimble, John Deere and Raven Read More
USDA
StewardshipUSDA Outlines Building Blocks For Climate Smart Agricul…
April 23, 2015
Today, the USDA has announced a comprehensive and detailed approach to support farmers, ranchers, and forest land owners in their Read More
Industry NewsArysta LifeScience Welcomes New Territory Sales Manager
April 23, 2015
Arysta LifeScience North America recently announced the addition of Kaitlyn Acaster to the Canadian sales team. Acaster will fill the Read More
Crop InputsMarrone Bio Innovations Opens New Research Greenhouse
April 23, 2015
Marrone Bio Innovations, Inc. (MBI), a leading provider of bio-based pest management and plant health products for the agriculture, turf Read More
Crop InputsDuPont Acquires Taxon Biosciences
April 23, 2015
DuPont has agreed to acquire Taxon Biosciences, Inc., a leading microbiome discovery company. This acquisition will build on DuPont’s in-house capabilities Read More
Farmer on tablet
ManagementStudy: Consumers Don’t Care If U.S. Farmers Feed …
April 23, 2015
“We’re feeding the world” is a mantra often used by those involved in farming and food to build support for Read More
Industry NewsCorporate Responsibility Magazine Names Monsanto One Of…
April 22, 2015
Corporate Responsibility Magazine (CR Magazine) named Monsanto Co. to its 100 Best Corporate Citizens List for 2015. This is the Read More
FertilizerSpring Nitrogen Management: Form And Timing
April 22, 2015
Most corn producers have planned their spring nitrogen program for 2015, and many have already started to implement their program. Read More
FMC 3Rive 3D
Industry NewsFMC Corp. Completes Acquisition Of Cheminova
April 22, 2015
FMC Corp. has completed the closing of its acquisition of Cheminova A/S, a multinational crop protection company based in Denmark Read More
SoftwareSyngenta Expands AgriEdge Excelsior Nationwide For 2015
April 22, 2015
Growers across the country can now take the guesswork out of improving their farm’s production, land value, farm stewardship and Read More
Cornfield near Sioux City Iowa
HerbicidesU.S. Regulators May Start Testing Food For Glyphosate R…
April 21, 2015
U.S. regulators may start testing food products for residues of the world’s most widely used herbicide, EPA told Reuters’ Carey Read More
FungicidesBRANDT Adds Zonix Biofungicide To Portfolio
April 21, 2015
BRANDT has added Zonix biofungicide to its rapidly expanding line of organic and sustainable products. Zonix is a contact fungicide that Read More