Citrus Greening: The Case for AgBiotech?

Oranges affected by citrus greening.

The huanglongbing (more commonly known as HLB or citrus greening) crisis continues to spread across the United States. The disease, which infects citrus trees and causes fruit to turn green and bitter, leaving it inedible, has spread rapidly across Florida after devastating citrus production in Thailand, Vietnam, Saudi Arabia, the Philippines, Indonesia, and southern China. The discovery of the disease in Los Angeles, California, in 2012 suggests that the future of California citrus may also be in jeopardy. The bacterial disease is highly infectious and there is no cure. The only treatment to date is to remove infected trees and quarantine infected areas, hoping to ride the disease out. No citrus variety has been found with natural resistance to the disease.

While some success has been found using high doses of antibiotics and insecticides (the disease is often transmitted through the saliva of the Asian citrus psyllid, an aphid-sized insect).  Recent research suggests that a transgentic orange containing a spinach gene may convey resistance to the citrus greening disease. But growers are concerned that public resistance to genetically modified foods may curtail acceptance of the new orange variety.

It’s an interesting test case for the status of genetically modified crops in the United States. The problem faced by the biotech industry is that there has never been a GM crop with clear benefits to the consumer. The commercialized traits to date have all centered on production characteristics—primarily insect resistance and herbicide tolerance. While these traits may make the production process easier, they carry no real benefit for the consumer who eats the GM food. With the HLB resistant orange, though, we start to see a clearer need for the technology. Indeed, as one researcher put it, “People are either going to drink transgenic orange juice or their going to drink apple juice.”