June, 2008       

VOL. 22, NO. 6                                                                             

IN THIS ISSUE:

         AND THE FAT LADY SANG

         MOISTURE

         CURRENT SITUATION

And The Fat Lady Sang—

According to the Texas Valley Citrus Committee, the 2007-08 Texas citrus season ended in early May.  TVCC issued its final report on fruit utilization through May 17.  Even though the estimated crop was down substantially from the 2006-07 season, fresh utilization of this season’s crop was essentially the same as that of the prior season—9.35 versus 9.34 million carton equivalents, respectively.
 
The final tally does show about 5.1 percent of the estimated grapefruit crop to be “remaining” which implies that the periodically re-adjusted estimate was still too high.  However, the substantial difference in processed grapefruit (down some 1.82 million carton equivalents) is about three times more than the supposed “remaining” supply.

If you had navels, you already knew that they were seriously off from the prior season, in part because of the failure to set in some groves and in part because of postharvest decay issues.  Grapefruit utilization was up slightly for the year, and early orange utilization was much higher for the year.
 
Valencia utilization was unbelievably low—both in comparison to the previous season and in comparison to the estimated supply.  Indeed, the Valencia “remainder” is almost 40 percent of the estimate.  Fresh utilization was only about three-fourths as much as the prior season, and processed utilization was only about one-fourth as much as the year before.  Aside from the obvious overestimation, Valencias experienced serious regreening problems that kept them out of fresh channels.

So, with total utilization down nearly 14 percent—but fresh utilization essentially unchanged from last year’s numbers—the difference had to come in the volume of processed fruit, and that number was down over 25 percent.  Obviously, there had to be substantial volumes of fruit that were unharvested, dumped, fed to the cows, and/or otherwise not directed into traditional reporting channels.

Even so, it is good to be through with 2007-08 fruit.  The major fruit drop periods for the 2008-09 crop have passed, so the new crop will size up and mature over the next few months, with a new shipping season to begin in September (hopefully).

Moisture—

I think about everybody got at least some rain back in mid-May, but there wasn’t a whole lot of it in most places.  Consequently, irrigation is probably the number one priority for grove operations until more rain comes.  At least now the crop is set, so irrigation is not quite so critical as it was for the first half of the year. 

By “not so critical”, I mean that cell division and fruit set have ended, so the maintenance of higher soil moisture levels is not as critical for the second half of the year when growth focuses on enlarging the fruit and sustaining the tree for the next season. 

All of this is based on the classic research by Dr. Bob Koo at Lake Alfred in which he amply demonstrated that soil moisture levels should be maintained at or above one-third depletion of field capacity during the first half of the season, but could be depleted to two-thirds before reapplication during the last half of the year. That program consistently produced optimal fruit size and total production, while maintaining overall tree development from year to year.

I know that it is tough to maintain the higher soil moisture levels with our typical flood irrigations, but the point is that from this time forward, you can likely go a few days longer between irrigations than you were doing earlier in the season.  By the same token, the greatest evapotranspiration loss occurs from now into early September, so don’t push it to the point of temporary wilting in the middle of the afternoon, as you really do not want to go there.

Current Situation—

Mites are starting to populate in some groves, so they should be closely monitored in coming weeks to be able to provide control measures before damaging levels occur.  I have not heard any reports that early-applied Temik is starting to break—and it normally continues to provide good control into at least late June and often well into July.

Scale crawlers should be appearing now, but if you wait until they settle permanently, lose their legs and secrete the waxy covering (in the case of armored scales such as Florida red and California red), you will only be able to kill them with oil sprays.  The usual contact materials simply cannot penetrate the waxy covering to kill the scale underneath.  Oil doesn’t penetrate the waxy covering either—it simply spreads out nicely over the waxy covering to smother the scale insect underneath.

I witnessed a unique failure to control guinea grass which had been mown down and allowed to regrow to six to 10 inches before the application of 1.5%  glyphosate in combination with 1% Citri-King oil, at a total rate of almost 60 gallons per treated acre.  Haven’t figured out the problem, but it appears that the grass was initially weakened (evidenced by a light chlorosis), but then apparently recovered (for the most part) with continued irrigation.  My best guess is that the grass was stressed (from the mowing and possibly insufficient soil moisture) at application, which would have limited uptake and control.

Since glyphosate has always been effective on guinea grass and since Citri-King has been reported to be effective on some species as a surfactant at 0.1%, as well as effective at 1.0% in combination with vinegar, I was surprised with the above situation.  If you know of a similar problem with guinea grass control this spring, I would like to hear from you so as to try to come up with a better theory (or support for this one) and a possible solution.  After all, the cost of mowing, the costs of the materials and the cost of the application were essentially wasted, as it all has to be done again.

And if you’re into college baseball, the NCAA College World Series will finish up regional action tonight, as six teams playing out of the losers brackets won yesterday, forcing rematchs today.  The six winners of the rematches will join the ten teams that won out yesterday to advance to the eight super regionals this weekend. A super regional is simply a two-team head-to-head best-of-three series; the eight winners will travel to Omaha for the finals a week later.  My alma mater (LSU) is in the super regionals. The Aggies lost a heartbreaker yesterday, but they took care of business tonight and will advance to meet Rice in the super regional.  My other alma mater, the University of Florida, unfortunately went two and out.

On the ladies’ side of the tournament (they play softball, but you might be amazed at how good some of those underhand lady pitchers are) up in Oklahoma yesterday, the fifth-seeded Lady Aggies came back in the second game of a doubleheader with the top-seeded University of Florida Lady Gators to make the finals against six-seeded Arizona State, which had previously knocked out third-seeded University of Alabama.  In today’s opener, the Lady Aggies were beaten 3-0 by Arizona State, but they get another shot tomorrow.



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