Breakthrough in fight against global disease of citrus trees

  • Published: Monday, April 5, 2021

WARRENSBURG, Mo. – Citrus greening is a devastating disease affecting trees across the globe. Research by University of Missouri Extension agricultural engineering specialist Shirin Ghatrehsamani may provide the key to overcoming citrus greening.

Before coming to MU Extension, Ghatrehsamani researched this issue as a Ph.D. student at the University of Florida. “The need for my research is related to the needs of Florida’s $9 billion citrus industry,” Ghatrehsamani said. “Many growers believe that without a process to treat existing trees, the citrus industry would disappear.”

As part of her research, Ghatrehsamani and her team tested a mobile thermotherapy system. They enclosed a tree in a tentlike insulator then injected a combination of hot water and steam to induce a fever.

“The bacteria that causes citrus greening is sensitive to the heat,” Ghatrehsamani explained. “One of the main challenges of the study was trying to find the right amount of time the tree could be exposed to a specific temperature to kill the bacteria but not kill the tree.”

Ghatrehsamani said this treatment for citrus greening works best on young trees. Researchers plan to create computer simulations to test thermotherapy on a variety of organisms.

“Just imagine the benefit to the agricultural industry if we apply the concept of this research to more than just a citrus tree,” she said, noting that the technique could help producers save time and money and avoid unnecessary chemical treatments.

Ghatrehsamani’s full report, “Simulation and Evaluation of Heat Transfer Inside a Diseased Citrus Tree During Heat Treatment,” is available at

Image available for this release:
Illustration of Shirin Ghatrehsamani’s mobile thermotherapy system: Left, a tree afflicted with citrus greening. Placing the mobile thermotherapy system around the tree, center, induces a fever to rid it of the heat-sensitive bacteria that causes the disease. The result, right, is a thriving citrus tree.

Writer: Adriene Aubuchon

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