Don't import citrus trees, ag official warns

If a dreaded citrus tree disease found last spring in the Los Angeles area were to spread to Yuma, it could be devastating to the multimillion-dollar citrus industry here as well as homeowners' ability to enjoy fresh fruit grown in their own backyards, warned a California agriculture official.

Ted Batkin, president of the California Citrus Research Board, was in Yuma recently to appeal to area residents with citrus trees to continue their vigilance against the insect that can carry the disease. And he stressed the importance of buying budwood from a local source if anyone wants to plant a citrus tree here.

With the confirmation in LA of the disease, huanglongbing (HLB) or citrus greening, it is even more critical to take such proactive measures, he said.

HLB is a bacterial disease that attacks the vascular system of plants. It does not pose a threat to humans or animals. The bacteria causing the disease can be spread by infected Asian citrus psyllids as the pest feeds on citrus trees and other plants. Once a tree is infected, there is no cure; it typically declines and dies within a few years.

“Every year we're closer to a solution,” Batkin said of the dread disease. “But we're still 20 years away from the development of resistant trees. That is the ultimate solution.”

In the meantime, it's up to people to do what they can to prevent the spread of the disease through detection and control of the psyllid and by not importing citrus tree materials from other states or countries, he said.

“Buying trees from local suppliers is the best source if people want to plant citrus,” Batkin said.

He noted that the infected tree in the backyard of a home in the LA area was brought in from another country. “We see a lot of that.”

So far there is only the one confirmed finding of the disease but there other suspect trees within a three- or four-block area that officials are continuing to test, he said. “By the nature of the disease, we expect to find it in other parts of LA. But before we can take legal action, we need to find the bacteria's DNA in the tree.”

Efforts to control the psyllid have also been stepped up, he said.

This is a critical time to look for the psyllid, he said, as the insect lays its eggs on the new growth of citrus trees now through December or January.

“If homeowners have citrus trees, they should check for the presence of the psyllid,” Batkin advised.

One obvious indication of the insect's presence is white threads on the tips of the new leaves. If found, he advised the homeowner to call the Arizona Department of Agriculture.

To date, the insect has been found in citrus trees in the Yuma County, but none has tested positive for the disease.

At stake is Arizona and California's Southwest's $2.2 billion lemon industry, Batkin said.

Arizona is the second-leading state in the U.S. for lemons and third for tangerines, much of that produced in Yuma County, according to the 2010 Arizona Agricultural Statistics. In 2009, lemons were grown on 7,155 acres in Yuma County for a value of nearly $19 million.

Reach Joyce Lobeck at jlobeck@yumasun.com or call at 539-6853.