JUNE, 2010      

VOL. 24, NO. 6                                                                             

IN THIS ISSUE:

VALLEY RESIDENTIAL SURVEY UPDATE
MEXICAN FRUIT FLY MEETING
FUNGICIDES FOR BLACK SPOT
CITRUS GREEENING IN THE VIRGIN ISLANDS
DEVELOPING NURSERY PROTOCOLS
THE 2009-10 SEASON

Valley Residential Survey Update

USDA-APHIS-PPQ has expanded the residential survey for citrus greening to include additional sites in Brownsville, Harlingen, Rio Hondo and Lyford, as well as in small communities along US 281 where it parallels the Rio Grande.  Total plant samples collected since the program began in 2008 are 17,883, with 4,639 of those forwarded for PCR testing.  Psyllid samples number 22,284 to date—all to tested by PCR for the presence of the citrus greening bacterium.

Combined with other tissue and ACP samples, to date there have been 5,411 tissue samples that did not pass screening and have been tested by PCR, with a few still in the process.  Also, a total of 21,349 of the total ACP samples have been tested, with a few still in the process. 
No sample—plant tissue or ACP—has tested positive for the citrus greening bacterium to date.

Citrus Greening in the Virgin Islands

On April 21, APHIS confirmed citrus greening disease in the US Virgin Islands.  The hosts were apparently all key limes (Mexican limes) located at an agricultural experiment station near St. Croix and on adjacent residential properties.

There have been no additional detections reported in Mexico since the discovery of the disease in Colima.

Annual Mexican Fruit Fly Meeting

The Annual Mexican Fruit Fly Meeting will be conducted June 16 at the Texas AgriLife Auditorium (what we used to know as Hoblitzelle Auditorium) in Weslaco, starting at 8:30 in the morning.  The program will include a report on the season just ended, and will address fruit fly activities in Mexico, Arizona, Florida and California.  In addition, there will be a discussion of the citrus protocols for the coming season.

Fungicides for Black Spot

Bayer and Syngenta have announced Section 2(ee) labels for GemR and AboundR fungicides, respectively, for use against the citrus black spot disease that has been detected in Collier County, FL.  What a 2(ee) label is is an “exception to use a product in a manner not permitted”, meaning that the product is allowed to be used on a non-label-specified target pest so long as the product is labeled for the crop in question. 

In other words, a Section 2(ee) label allows a manufacturer to make an update before the federal label has been amended.  In this case, citrus black spot is not identified on the GemR or AboundR labels as a targeted pest (since the disease was not present when the labels were approved by EPA), but the labels are for use of the products on citrus.  Ergo, EPA created the Section 2(ee) label exception to permit such use until the federal label has been revised or amended.

Developing Nursery Protocols

APHIS is presently developing  a series of nursery protocols aimed at regulating the interstate movement of citrus nursery stock from states that are under quarantine for citrus canker, citrus greening and/or Asian citrus psyllid to non-quarantine areas.  Essentially, the protocols would ultimately allow the movement of citrus nursery stock from quarantined states to all other states—under compliance agreement with APHIS and the protocols for growing, treating and inspecting/testing of subject nursery and its stock. 

A key issue here seems to be “all other states”: the title says to “non-quaratine areas” but the wording inside the draft document does not make that distinction. Hopefully, this will be clarified or better stated when the telephone conference is concluded and the final version of the protocols is implemented.

There is an exception protocol for nursery stock grown in states which are under federal quarantine for the psyllid only, which includes Texas.  If a Texas citrus nursery wants to ship citrus plants into states that do not produce citrus commercially, it would be business as usual under existing compliance agreements—but the plants cannot pass through a citrus-producing state enroute to the final destination. 

The 2009-10 Season

The season is over, but it’s not in the books as yet.  TVCC expects to produce its Final Utilization Report in the next couple of days, so my usual recap of the season will have to wait until next month in order to get this newsletter into the email and on the web.

JULIAN W. SAULS, Ph.D.
Professor & Extension Horticulturist
2401 East Highway 83
Weslaco TX 78596