A new study has uncovered a collective growth strategy of sunflowers in dense environments that involves the flowers performing a “dancing” motion, Tel Aviv University said on Tuesday.
The study found that sunflowers optimize their growth direction through random movements. This way they avoid shading each other and can maximize sunlight.
This discovery could shed light on a long-standing scientific question regarding the functional role of circumnutation, a type of cyclical movement observed in plants, Tel Aviv University said.
The study was led by Prof. Yasmine Meroz of the School of Plant Sciences and Food Security at the Wise Faculty of Life Sciences at Tel Aviv University in collaboration with Prof. Orit Peleg of the University of Colorado Boulder.
The research team also included Dr. Chantal Nguyen from Boulder, Roni Kempinski and Imri Dromi from Tel Aviv University. Their results were published in the journal Physical Examination X.
Previous studies have shown that sunflowers planted in densely planted fields grow in a zigzag pattern to avoid shading each other.
This growth pattern allows them to maximize the absorption of sunlight for photosynthesis on a collective level. Sunflowers can distinguish between the shadow of a plant and the shadow of a non-plant object, such as a building, and change their growth direction accordingly.
How was the study conducted?
According to the study, the team conducted experiments in a controlled laboratory setting, growing sunflowers in close proximity and capturing their growth using time-lapse photography. The resulting footage showed that the sunflowers exhibited a “dancing” behavior, with each bloom moving randomly, seeking the best angle to avoid shading its neighbors.
This phenomenon was first observed by Charles Darwin, who discovered that plants exhibit cyclical movements during growth, called circumnutation.
Although this behavior has been known for over a century, its functional role remains unclear until today, except in specific cases such as climbing plants. The current study provides new insights into the importance of these movements and shows that they play a crucial role in optimizing collective growth, said Tel Aviv University.
The researchers quantified the sunflowers’ movements through physical analysis and computer simulations. They found that they varied greatly in magnitude, ranging from minimal shifts to movements of up to two centimeters every few minutes.
These random movements help minimize shading among the sunflowers, thereby improving their ability to capture sunlight.
The range and randomness of these movements are crucial to minimise shading and maximise photosynthesis. Tel Aviv University concluded that this can provide new insights into the adaptive strategies that plants use to thrive in highly competitive environments.
