Scientists at the university discovered that when a green laser beam strikes a citrus tree, the light the tree emits varies according to its health. They already know how to identify the disease in certain types of orange trees and in laboratory nursery trees. The technique should be available for field applications within a year.
Research co-ordinator Luiz Gustavo Marcassa reports that trees emit a yellow light if they are contaminated and a red light when they are healthy. The purpose of the joint research is to develop equipment to identify plant diseases without the need for specialist training of technicians.
The new discovery could prove a major breakthrough in on going fights against the disease in major citrus production areas such as Brazil and Florida and could save thousands of healthy trees. Under existing canker eradication methods, entire plantations of healthy trees are destroyed if just one tree shows visual signs of the disease. This is because trees can already have fallen victim to citrus canker before symptoms are visible. But using the laser technique unhealthy trees can be indentified much earlier.
