Researchers Show the cause of Productivity Loss in the Fluctuating Light of Maize Crop Canopies

Oct 12, 2022

A team from the University of Illinois has measured the dynamic leakiness of CO₂ from C4 plants. Previous studies had measured the leakiness under steady-state conditions, but this group took the measurements to prove that leakiness can and should be measured as a dynamic parameter.

"Last year, we predicted that during photosynthetic induction, C4 cycle activation is faster than the Calvin-Benson cycle, which would cause more CO₂ leaking, but we didn't have any evidence," said Yu Wang, a postdoctoral researcher at Illinois, who led this work for a research project called Realizing Increased Photosynthetic Efficiency (RIPE). "Now our results prove it's real. We have the first measurements of the leakiness under dynamic conditions."

While the group's previous prediction, published in the Plant Journal last year, was a proven concept, these first-of-their-kind measurements show that their modeling of the C4 and C3 photosynthetic cycles are accurate. Their recent work, studying sorghum and maize, was published in New Phytologist.

"Our research shows that during photosynthetic induction, the activation of C4 cycle is faster than the Calvin-Benson cycle," said Wang. "This is why leakiness is higher for the first several minutes after the light comes on."

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Video: Dicamba Returns for Georgia Farmers: What the New EPA Ruling Means for Cotton Growers

After being unavailable in 2024 due to registration issues, dicamba products are returning for Georgia farmers this growing season — but under strict new conditions.

In this report from Tifton, Extension Weed Specialist Stanley Culpepper explains the updated EPA ruling, including new application limits, mandatory training requirements, and the need for a restricted use pesticide license. Among the key changes: a cap of two ½-pound applications per year and the required use of an approved volatility reduction agent with every application.

For Georgia cotton producers, the ruling is significant. According to Taylor Sills with the Georgia Cotton Commission, the vast majority of cotton planted in the state carries the dicamba-tolerant trait — meaning farmers had been paying for technology they couldn’t use.

While environmental groups have expressed concerns over spray drift, Georgia growers have reduced off-target pesticide movement by more than 91% over the past decade. Still, this two-year registration period will come with increased scrutiny, making stewardship and compliance more important than ever.