To help organic producers more effectively combat citrus greening, The Organic Center, Washington, D.C., released a white paper that mines the existing body of scientific literature devoted to citrus greening, compiles relevant results and synthesizes them to create a farmer/nurseryman-focused document. 

The study, funded by the UNFI Foundation, Providence, R.I., consolidates existing literature on allowable methods for combating citrus greening in organic groves. 

“Organic citrus producers have suffered terrible losses from citrus greening, and they need to be aware of organic solutions to ward off this disease,” says Dr. Jessica Shade, director of science programs. “Our goal in releasing this paper is to help organic citrus growers fight this deadly disease without resorting to dangerous chemicals, genetic engineering or other methods not in compliance with organic standards.”

An organic solution

Citrus greening threatens the citrus industry on a massive scale. The highly destructive disease can spread quickly, and once a tree is infected, it cannot be cured.

Currently, the most common method for controlling citrus greening is by spraying large amounts of synthetic pesticides such as neonicotinoids. These toxic sprays have had only limited success, and are responsible for large-scale bee die-offs.

Organic citrus growers need ways to control citrus greening through organic practices, without the use of toxic chemicals or genetic engineering.

This paper examines research from multiple citrus systems to distill the techniques allowed under organic certification to help control citrus greening. Examination of available literature, unpublished research data and grower observations have produced evidence that growers may be able to thwart the threat of citrus greening to produce marketable fruit.

These organic strategies include combining strict disease prevention, diligent scouting, ACP control, nutritional support of healthy and infected trees, implementation of biological controls and the planting of cultivars considered tolerant or resistant to citrus greening. 

But, despite the strategies outlined to help organic farmers combat citrus greening, more research is needed to overcome this terrible disease.

“Conventional and organic farmers alike have had their groves decimated by citrus greening,” Shade says. “While our report provides tools for them to help them in their struggle, without more research we’ll continue to see a dramatic decline in citrus production – especially organic citrus.”

The Organic Center works with a team of growers, researchers and community members, including the University of Florida (UFL), Gainesville, Fla.; Ellen Cochrane, graduate student at UFL; professor Jawwad Qureshi, assistant professor entomology at UFL; professor Philip Stansly, former professor and international entomologist at UFL; Dr. Kim Bowman, research geneticist of plants at U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS); professor Reza Ehsani, professor, agricultural and biological engineering at UFL; professor Michael Rogers, associate professor of citrus integrated pest management, entomology and nematology department at UFL; professor Ronald Brlansky, professor emeritus, plant pathology department, citrus research and education center at UFL; professor Fritz Roka, associate professor of agricultural economics at UFL; Dr. Tracy Misiewicz, associate director of science programs for The Organic Center; Ben McLean III, vice president of Uncle Matt’s Organic; and the Florida Organic Growers organization, Gainesville, Fla.