California Ag inspector checks for ACP in residential neighborhood

California's vigilance in HLB fight could reap rewards

The recent dust-up of Huanglongbing (HLB) discoveries in southern California could arguably be a good thing for commercial citrus growers. Before you confuse this with the premise that a lethal bacterial disease in citrus is a good thing, let me explain.

Local and state officials found HLB in early July in California’s San Gabriel Valley because they were looking for it. Why were they looking for it and how did they know where to look?

The short answers to both deal with the discovery of HLB in Hacienda Heights in 2012 and the fact that Asian citrus psyllids, the flying bug that moves the disease around by feeding on infected plants, is widespread in southern California.

There are other reasons southern California is a hot-spot for the ACP and HLB.

Southern California’s urban landscape is full of citrus. This creates plenty of opportunities for the psyllid to feed, breed and spread HLB.

Because urban residents tend not to treat their trees with pesticides like commercial growers, pests and disease can become a problem in urban centers. A good example of this can be seen in a city park in Redlands where small citrus trees are covered with pests, including ACP, scale and ants.

According to officials with the California Department of Food and Agriculture’s Citrus Pest & Disease Prevention Program, testing protocols employed by state and federal officials, coupled with the knowledge of what to look for, led inspectors to the infected trees in San Gabriel.

The problem is the disease apparently has a period of latency – a time in which trees are not visibly symptomatic but the bacteria is moving through the tree. This may have led to some complacency on the part of some citrus growers.

Several weeks ago I was at a citrus meeting in the heart of California’s citrus belt. An unscientific survey of about 200 attendees in the room by a University of California professor queried attendees through a series of question-and-answer responses via computer program on HLB and how important an issue they thought it was.

The answers were not encouraging as some in the room did not think HLB was as big a problem as portrayed by the citrus industry.

This is why Florida has lost considerable citrus production and juice plants are printing financial ledgers in red ink. Growers and industry leaders there simply thought the ACP was an inconsequential bug during the flush period.

Most of us have likely heard the English proverb “Necessity is the mother of invention.” If that’s true, then the discovery of HLB in California’s urban neighborhoods should be the wake-up call the industry needs to leave no stone unturned in battling this insidious disease.

Science and technology aside, it would seem from the citrus grower meeting in Exeter that more effort is needed to convince growers, farm managers and others in the citrus industry that the problem is very real and they have a role in addressing its challenges.

Commercial growers and backyard gardeners alike should know how to treat for the psyllid and what to do if they find it. They also need to be aware of the disease symptoms and who to call if they suspect a problem.

The CDFA has information online, as does the University of California, about the ACP and HLB. 

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