Citrus Greening Disease Confirmed In Rio Grande Valley For First Time Ever - NYT
On Jan. 13, the first-known case of citrus greening disease in Texas was confirmed on a Rio Grande Valley orange tree. The tree showed the telltale signs: undersize, discolored fruit and curled, mottled yellow leaves.
The one case in a San Juan grove became 14, and the outbreak brought the Valley’s citrus harvest season to a halt, as the United States Department of Agriculture investigates how far it had spread. After getting the go-ahead, quarantined growers, pressed to move the last of the year’s oranges and grapefruits to market, cautiously resumed harvesting on Feb. 1. But they fear the disease could spread and seriously damage their industry.
Steve Lievens, who grows Rio Star grapefruits and Valencia oranges in the groves his father established in 1950, worries about being able to identify the disease. “There’s a lot of difference between looking at the greening on a slide show or on some laminated cards and looking at it out in the field,” Mr. Lievens said. “We’re going to have to really school ourselves hard to say with confidence we feel like a tree does or doesn’t have greening.”
Greening disease is caused by a bacterial pathogen that is transmitted to the trees by an insect, the Asian citrus psyllid. The disease, which is harmless to humans, starves citrus trees by clogging their vascular systems with bacteria, preventing the transport of sugars and other nutrients. The tree eventually dies.
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http://www.nytimes.com/2012/02/12/us/greening-disease-in-rio-grande-valley-has-texas-citrus-growers-on-alert.html?_r=1