Fungus halts Texas citrus shipments
by Chip Carter | November 23, 2010
Texas citrus growers have voluntarily placed a temporary hold on shipping to
other states as they deal with an outbreak of sweet orange scab first reported
Oct. 12 in The Produce News.
Texas growers voluntarily halted citrus shipments to other states Nov. 4, and
the ban was to be lifted Nov. 19 but has been extended indefinitely.
Ray Prewett, president of Texas Citrus Mutual in Mission, TX, said that the
voluntary quarantine was a good-faith effort by the Texas industry to
investigate the infestation further before potentially putting other states at
The U.S. Department of Agriculture's Animal & Plant Health Inspection Service
confirmed the presence of Elsinoë australis, or sweet orange scab, in Texas
and Louisiana in August. It was the first time the fungal pathogen had been
detected in the United States, though it is prevalent in South America, Fiji and
Samoa. Infected citrus trees were found on residential properties in Harris and
Orange counties in Texas, and in Orleans Parish in Louisiana. The pathogen
results in scab-like lesions on fruit rinds and sometimes on leaves and twigs;
the damage is superficial, does not affect quality or taste, and poses no threat
to humans, but infected fruit may drop prematurely and the disease may stunt
Even though confirmation of the outbreak did not come until August,
researchers believe the initial infection in Texas took place in June. Since
then, the fungus has been found in Willacy, Cameron and Hidalgo counties in
Texas' Rio Grande Valley, as well as in some research orchards.
Texas shippers are working with APHIS to determine if the fungus poses a
threat to other growing regions. Sweet orange scab is rare enough that most
of the literature regarding it is woefully out of date. Mr. Prewett said that the
most recent scientific study Mutual could find was published in 1937.
The temporary quarantine will affect California more than other states
because Texas ships about 25 percent of its orange crop to the Golden State
this time of year.
"The early detection of this disease clearly demonstrates the effectiveness of
the Citrus Health Response Program," said Rebecca Bech, deputy
administrator for APHIS' plant protection and quarantine program. "We have
taken swift action by issuing emergency action notifications requiring that
fruit, leaves, branches and other plant parts remain on these properties to
prevent the spread of the disease. We are communicating closely with our
partners in Texas and Louisiana as we continue to survey to determine the
boundaries of the infected areas."