Sun-induced chlorophyll fluorescence (SIF) occurs when a portion of photosynthetic energy, in the form of near-infrared light, is emitted from plant leaves. Researchers report that it is possible to detect and predict heat damage in crops by measuring the fluorescent light signature of plant leaves experiencing heat stress.
To clarify the link between SIF and crop yield, researchers from the University of Illinois used a hyperspectral sensing system to measured SIF above soybean crops in the university’s Temperature Free-Air-Controlled Enhancement experimental plots. The set up monitored changes in chlorophyll fluorescence of soybean leaf canopies in a controlled environment using infrared lamps to raise temperatures 1.5, 3.0, 4.5, and 6.0 degrees Celsius above the ambient crop canopy temperature. The study establishes a correlation between heat stress, SIF and grain quality and clarifies how heat stress affects photosynthetic performance and crop yield. The study was published in the journal Global Change Biology.
"The technique may provide a tool for breeders to identify more heat-resistant crops and help farmers select the best crops to grow in the U.S. Corn Belt as temperatures rise, as predicted by many climate models," said Lisa Ainsworth, a plant biology professor and USDA scientist at Illinois.
If collected via satellite, the fluorescent signal could support widespread monitoring of growth and crop yield under the heat stress of climate change.
Photo: Illustration showing (a) the experimental setup and photos of field measurement (b) a researcher using a spectroscopy system and (c) the canopy chamber system. Credit: Hyungsuk Kimm