Crop response to nighttime temperature research shared

Dr. S.V. Krishna Jagadish, a professor of crop ecophysiology at Kansas State University (KSU), joined the Agriculture Today podcast with host Eric Atkinson on July 29 to identify the impact of high nighttime temperature readings on crop productivity.  

Jagadish has been working on crop nighttime temperature reading research for the last 12 years.  

Temperature impact 

Research started when Jagadish was studying in the Philippines, before he started working for KSU. There, he worked with rice and noticed during periods of high nighttime temperatures, a chalk-like texture resulted in the grain. At KSU, Jagadish studied the same sensitivity in wheat.  

“We started with rice, and over the last six years we have been studying wheat, where we have made some significant findings, and we have now transitioned into looking at corn,” says Jagadish. 

“Temperatures start rising when plants are finished flowering and grains are starting to fill,” explains Jagadish. “This stage is extremely sensitive to temperature conditions.”  

Particularly after flowering, farmers start to see plants mature. When nighttime temperatures increase, plants have a large amount of carbon loss due to respiration.  

“In simple terms, the carbon of the starch that should have ended up in the grain is consumed for the maintenance of the plant and lost,” states Jagadish. “Producers will get less yield and poorer quality grain.” 

Quality and yield 

“When temperatures increased by one degree Celsius, we saw a loss of about five percent in yield,” explains Jagadish. “This is just an average number, but there are some producers who lose about 13 percent of their yield due to high temperatures.” 

Jagadish shares, there is a lot of genetic diversity to explore within this experiment, and the researchers are focused on both crop yields for the producer and crop quality for the consumer.  

“At the end of the day, what ends up on the plate is the most important thing for the public consumer,” says Jagadish.  

Jagadish stresses how it is important to find a hybrid with genes resistant to rising evening temperatures. 

“With warm nighttime temperatures, we see it’s not just the yield that is important, but because of the loss of starch, the grain seems be increasing in lipid and protein content,” explains Jagadish. “Because of these dynamics, the elasticity of bread may be affected, and bread may become brittle with quality seriously affected.” 

“We jumped from wheat to corn and there’s a strategic reason we did this,” Jagadish shared, explaining the differences in both crops. “These are both major cereal grains, and they are cereals heavier in starch. Cereal grains are impacted the most by carbon loss.” 

“The impact of starch loss in corn is huge compared to wheat,” he says, noting a corn stalk is much larger than both a single grain of rice or a single spike of wheat, thus the impact of temperatures affect corn more directly.  

“Corn plants are much larger compared to that of rice or wheat, with almost two-and-a-half times the biomass,” Jagadish continues. “When nighttime temperatures start to increase, the plant needs to maintain all of the activity in the biomass. Corn maintains more biomass, which means it is using more carbon and farmers will see the impact in the grain.” 

According to Jagadish, this larger impact of starch reduction in corn will likely have an impact on animal fuel and biofuel production. 

As the study at KSU continues, Jagadish is hopeful they will see a positive impact in at least one of the 12 hybrids they have planted, and hopes it will help producers battle rising temperatures.  

Cameron Magee is an intern for the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.