Study shows how sunflowers maximize collective sunlight capture

JERUSALEM, Aug. 19 (Xinhua) — Researchers from Israel and the United States have discovered that sunflower plants “dance” during growth to avoid shading each other and maximize sunlight capture, according to a statement issued by Tel Aviv University (TAU) on Monday.
Previous studies have shown that when sunflowers are densely planted and shade each other, they grow in a zigzag pattern, moving forward and backward, to avoid mutual shading and optimize sunlight exposure, thereby enhancing collective photosynthesis.
In the new study, researchers from TAU and the University of Colorado, Boulder, explored how sunflowers “know” to grow in a way that maximizes sunlight capture for the entire group.
They grew sunflowers in a high-density environment, photographing their growth every few minutes and compiling the images into a time-lapse video.
Through quantifications and computer simulations, the team demonstrated that these random movements help the plants collectively reduce shadowing.
They observed that the range of sunflower “steps” varied widely, from minimal displacement to movements of up to two centimeters in various directions every few minutes.
The researchers concluded that sunflowers use both small, slow steps and large, quick ones to find the optimal arrangement for the group.
They found that if the range of movement were either smaller or larger, it would result in increased mutual shading and reduced photosynthesis.
The researchers likened this behavior to a crowded dance party, where dancers move to create space without interfering with each other.
The study was published in the journal Physical Review X. The researchers said they addressed a long-standing scientific question about the purpose of natural movements known as circumnutations. ■