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

FungicidesReport: Sudden Death Syndrome Symptoms Appearing In Soybeans
July 30, 2015
Last week, symptoms of sudden death syndrome (SDS) began to appear in April 15-planted soybeans at the University of Illinois’s Read More
Seed/BiotechAdvanta Seeds Adds New Phoenix Corn Hybrids
July 30, 2015
Corn growers in the High Plains and Western states have new options available for the 2016 growing season from Advanta Read More
GYPSOIL Blendable Pellets
Crop InputsBeneficial Reuse Management Launches Pelletized Gypsum Product
July 29, 2015
Beneficial Reuse Management (BRM) announced this week at Ag Media Summit that its GYPSOIL Pelletized Products Division will open a Read More
FertilizerKoch Agronomic Services Launches N-TEGRATION Technology
July 27, 2015
Koch Agronomic Services, LLC (KAS) has launched  N-TEGRATION Technology, a process technology platform designed to enable production of enhanced efficiency fertilizers at Read More
Top 100 Articles
CropLife 100Allied Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
CropLife 100Pinnacle Purchases California-Based Specialty Crops Retailer
July 20, 2015
Pinnacle Agriculture Holdings has successfully acquired California-based NH3 Service Co.  Operating as part of Pinnacle’s Performance Agriculture brand, the new locations Read More
Asmus Farm Supply liquid fertilizer facility features 20,000 square feet
CropLife 100Slideshow: Asmus Farm Supply Shows Off Its New Liquid Fertilizer Facility
July 15, 2015
Asmus Farm Supply, Rake, IA, recently added a new liquid fertilizer facility to its company operations. The new liquid fertilizer Read More
CropLife 100Wilbur-Ellis Feed Division Facilities Receive Safe Feed/Safe Food Certification
July 13, 2015
Wilbur-Ellis Co.’s Feed Division, a marketer and distributor of value-added feed ingredients for the aquaculture, livestock and pet food industries Read More
CropLife 100BRANDT Expands To Brazil With Acquisition
July 8, 2015
BRANDT has acquired a majority interest in Target Brasil Fertilizantes Ltda. through its Brazilian subsidiary. Target Brasil manufactures, distributes and Read More
Milan Kucerak, president/CEO, West Central
CropLife 100West Central Cooperative And Its New President Are A Match Made In Deviation
June 29, 2015
To appreciate just how unique West Central Cooperative is in the world of ag retail, an observer need only consider Read More
Latest News
CropLife 100Allied Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
FungicidesReport: Sudden Death Syndrome Symptoms Appearing In Soy…
July 30, 2015
Last week, symptoms of sudden death syndrome (SDS) began to appear in April 15-planted soybeans at the University of Illinois’s Read More
Seed/BiotechAdvanta Seeds Adds New Phoenix Corn Hybrids
July 30, 2015
Corn growers in the High Plains and Western states have new options available for the 2016 growing season from Advanta Read More
ManagementTechnology and agriculture: a Futurist’s Perspective
July 30, 2015
Futurist David Zach, speaking at this week’s InfoAg Conference in St. Louis, shared thoughts on the benefits and limitations of Read More
Biofuels Plant in Lousiana
Industry NewsIdle Biofuels Plant In Louisiana To Reopen As Ammonia F…
July 30, 2015
A Lithuania-based company plans to spend $265 million to reopen an idle biofuels refinery in Grant Parish as an ammonia Read More
FFA at Monsanto Booth at the 2015 National Farm Machinery Show
Industry NewsFive Students Receive The 2015 Monty’s Plant Food Compa…
July 29, 2015
This fall, five college-bound students will have financial support through the Monty’s Plant Food Company FFA Scholarship. All five scholarship Read More
GYPSOIL Blendable Pellets
Crop InputsBeneficial Reuse Management Launches Pelletized Gypsum …
July 29, 2015
Beneficial Reuse Management (BRM) announced this week at Ag Media Summit that its GYPSOIL Pelletized Products Division will open a Read More
StewardshipOhio Water Quality Project To Determine How Much Phosph…
July 27, 2015
Researchers with the College of Food, Agricultural, and Environmental Sciences at The Ohio State University are looking for farmers in Read More
FertilizerKoch Agronomic Services Launches N-TEGRATION Technology
July 27, 2015
Koch Agronomic Services, LLC (KAS) has launched  N-TEGRATION Technology, a process technology platform designed to enable production of enhanced efficiency fertilizers at Read More
HerbicidesExpert: IARC Herbicide Classifications Leading To Confu…
July 24, 2015
Few people in the crop protection industry had heard of the International Agency for Research on Cancer (IARC) before this Read More
ManagementFCI Trade Summit Update & Precision Tank Turns 50
July 23, 2015
Editors Dave Frabotta and Eric Sfiligoj discuss the upcoming FCI Trade Summit in Las Vegas, NV, and how Precision Tank Read More
Palmer pigweed seedhead in cotton
HerbicidesUSDA Deregulates Dow AgroSciences’ Enlist Cotton Trait
July 23, 2015
The USDA today issued its decision deregulating Dow AgroSciences’ Enlist cotton trait in the U.S. The USDA has now completed its Read More
Industry NewsVerdesian Life Sciences Showcases Versatile Product Por…
July 23, 2015
Technology has revolutionized agriculture by bringing farmers, retailers and distributors to the forefront of the digital age. To meet the Read More
FertilizerWSJ: Cf Industries Exploring Merger With Dutch Chemical…
July 23, 2015
U.S. fertilizer maker CF Industries is in advanced merger talks with Amsterdam-listed chemical company OCI NV, the Wall Street Journal Read More
HerbicidesNufarm Releases New Panther SC Herbicide
July 23, 2015
Nufarm has announced the availability of new Panther SC herbicide. Panther SC is the first liquid formulation of flumioxazin available Read More
EquipmentFarmLink Launches Farm Equipment Sharing Program
July 23, 2015
FarmLink has introduced a new online farm equipment sharing community – MachineryLink Sharing – leveraging this new economy business model Read More
HerbicidesCould The South’s Most Troublesome Weed Represent A Thr…
July 22, 2015
Palmer amaranth is undoubtedly the most troublesome weed in the southern United States, taking a devastating toll on both cotton Read More
Industry NewsH.J. Baker Hires New Director Of International Sales
July 22, 2015
Global Agriculture firm H.J. Baker announced today that Steve Langley has joined the company’s Crop Performance Division and Animal Health Read More