JANUARY, 2010      

VOL. 24, NO. 1                                                                             

IN THIS ISSUE:

FREEZE ALERT
NEW HLB DETECTIONS IN MEXICO
WEATHER AND HARVEST
AREA-WIDE PSYLLID SPRAYING
UTILIZATION STATUS

Freeze Alert

On Monday, the National Weather Service was calling for a hard freeze for the Valley for this weekend, but the severity of the forecast seems to have attenuated somewhat overnight.  As of Tuesday morning, NWS is predicting upper 20s to lower 30s for the end of the week into the weekend.

The Weather Channel is predicting lows of about freezing Thursday morning, 28-32 degrees Friday morning and 33-37 Saturday morning.

AccuWeather is currently forecasting lows of about freezing for Thursday morning, a couple of degrees colder on Friday morning and about freezing again Saturday morning.

Given the above, the best advice is to stay tuned to your preferred weather prognostication service, whether online, radio, TV or paper.

With the exception of extremely cold orchard sites, there does not presently appear to be much danger of temperatures dropping to critical levels for fruit damage.   The conventional wisdom is that it takes about 4 hours at or below 28o to put ice in oranges, probably the same duration at or below 27o for internal icing of grapefruit. 

New HLB Detections in Mexico

In what may be old news by now, on December 10, officials with SENASICA announced the confirmation of HLB on the Pacific Coast of Mexico in the states of Jalisco and Nayarit.  The infections involved 51 positive trees from Puerto Vallarta on the south to San Blas on the north.  All tree detections were in dooryards.
In addition, 17 positive psyllid samples were discovered, including some in commercial orchards in Nayarit.  Officials are actively checking for symptoms within those orchards as well as for additional hot psyllids.  Too, officials are still conducting delimiting surveys all over the area.

The extent of the infections in trees suggests that the disease has been there longer than anyone would like to think.  No source of the infections is known, but there is some belief that contaminated material somehow arrived in the tourist resort of Puerto Vallarta and spread north from there.  Puerto Vallarta is a popular tourist destination, with both air and cruise ship

If you don’t have Google Earth, this area is about 1050 miles due west of the finds over in Yucatan state.  San Blas is about 550 miles southwest of the Valley, but there are a couple of mountain ranges in between.  Of more concern to California and Arizona, San Blas is about 950 miles south-southeast of Yuma, Arizona and about 1050 miles southeast of San Diego—and there is no mountain range in between. 

Weather and Harvest

It seems that the rain gods that so penalized the Valley from October, 2008 to August, 2009 were trying to atone for the long drought by trying to bring the annual rainfall up to near average before 2009 ended. Mostly slow, steady, all day type rains came in on November 30 for a couple of days, returning again and again with the latest on December 26. Through Thanksgiving, my totals were running only about 65 percent of the annual average, but now are closer to 90 percent.

The December rains have created problems for harvest crews, but apparently most packinghouses were finding enough orchards that crews could get into, as shipments since Thanksgiving have been pretty good.  The rains of mid-December were substantial, especially on already wet ground, promising more difficulties for harvest.  Fortunately, the Christmas holiday made for a short week in terms of shipping, so the industry was able to work around the rain and continue to meet customer demand for fruit.

Generally overcast skies and cool conditions have been the rule for December, but nothing serious in the way of freezing temperatures occurred.  One frosty night early in the month resulted in burn to sensitive tropical plants and a little top burn on sugar cane, but no damage to citrus.

Cold weather was experienced in some California orchards, but the reports are that there was no damage to the crop or to the trees.  More recently, a cold spell in Florida reportedly caused no damage to citrus.

Area Wide Psyllid Spraying

With HLB’s jump across Mexico, the threat of greening is becoming more real by the month. We still don’t know when it will reach the Valley, but it does seem more likely that it will—it’s merely a question of time. 

We also don’t know for a fact that greening is not already in Texas; we know only that it has not been detected here.  The experience with greening and psyllid in Florida has provided us the direction to try to limit the spread of the disease—even before it gets here.  That direction is to take proactive steps to control the psyllid vector.  The logic is simple:  without vectors, the disease does not spread, so try to control the vector.

Because the psyllid can and does fly from grove to grove, vector control is best achieved by a coordinated spray effort across all citrus in a short time span, thus killing most of the overwintering psyllids and limiting the number that escape to unsprayed groves where they can survive to later move back into sprayed groves.

The details have been pretty well worked out for a proposed area wide psyllid spraying later this month.  To reach as many growers as possible, a series of meetings has been scheduled across the Valley for next week: 

Monday, January 11—Harlingen.  Noon, with lunch.  Best Western Casa Villa Suites at 4317 S. Expressway 83.  That’s between New Hampshire and Ed Carey, on the north side.

Tuesday, January 12—Weslaco.  Noon, with lunch.  TAMU-K Citrus Center.

Wednesday, January 13—Mission.  Noon, with lunch.  Holiday Inn Express, 901 S. Shary.  That’s about a block or so south of the Expressway, on the east side of Shary Road (FM 494).

Friday, January 15—Mission.  TCM offices, with lunch.  This one is for organic growers.

Registration is essential for whichever of the meetings you plan to attend so that the appropriate number of meals can be provided. There are two ways to register for attendance:  1)  Call Martha or Edith at 956/584-1772 or 2) Go online to http://www.viewpointpro.com/CG_Registration.

Hopefully, work with Texas Department of Agriculture officials will have resulted in much-needed 24C labels for some of the products that we need.  The products are labeled already, but several did not have the necessary label for low volume application.

Utilization Status

Through December 26, the Texas Valley Citrus Committee reports a total fresh citrus utilization volume that Is only slightly behind last season, with about 96.5 percent as much fresh fruit shipped as was shipped to the same period last season.  Perhaps the dropoff can be blamed on the December rains.

In terms of quality, the fruit seems to be better this season, judging by eliminations to processing.  Orange packouts are running about 90.3 percent of harvest; grapefruit packouts are presently at 76.0 percent of the total harvest.  Diversion to processing is down substantially from a year ago, the amount being about 63 percent of last season for oranges and 77 percent of last season for grapefruit.


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