Citrus trees start dying for no apparent reason in Florida.  A plant pathologist arrives to look at dying citrus trees and starts running a diagnostic list, much the same way a medical doctor assesses sick patients.

In one recent case, a plant pathology expert witness was brought in for causation relative to dying citrus trees and nearby farms with water run-off.  It’s a familiar situation that goes in and out of the news in agricultural areas where water district authorities are charged with managing the balance between water for crops and livestock as against environmental preservation projects and residential water supplies.


The case involves the impact of excess irrigation water flowing downstream into an eco-sensitive area, impacting the depth, duration of flooding, frequency of flooding, and seasonality of flooding.  It wasn’t just the citrus trees; the entire ecology was at risk.

The plant pathologist studies botany, microbiology, soil and crop science, molecular biology, ecology, and genetics.  Many plant pathologists have college and graduate degrees, and are found in the university research setting.

In essence, plant pathology deals with the symptoms, causes, damage, spread, and control of plant diseases.  The plant pathology expert witness can provide testimony both as to causation and to damages, including areas of relocation of trees from construction sights, rerouting of utilities through sensitive and historic trees, and tree valuations.  The plant pathologist also speaks to seeds, genetic and other defects in seeds, and reliability and susceptibility of seeds.

The plant pathology expert witness can also enhance testimony in cases where issues involve healthy food, and their credentials may include employment with the U.S. Department of Agriculture and the U.S. Forest Service.  The USDA website advises studies begin as early as high school in courses like biology, chemistry, physics, and math.

Plant pathology is a science practiced the world over, particularly in our global economy.  A coconut plantation affected with Weligama Coconut Leaf Wilt Disease in Sri Lanka may find its way to a supportive host environment via freighter half way around the world.  And Sudden Oak Death in California can be just as much a concern for study and lawsuits in Europe and Australia.

Most litigators cannot diagnose plant disease or identify the source of plant death.  In cases involving the destruction of commercial crops, the court and jurors rely on a plant pathology expert witness to identify the culprit so there can be a fair settlement or judgment for the case.

by Paloma A. Capanna, Attorney