FEBRUARY, 2007       

VOL. 21, NO. 2                                                                            




After an atypical early winter that saw record highs in much of the northern and eastern states, things turned around dramatically during January.  First, there was the severe freeze in California that destroyed an as-yet undetermined amount of this year’s citrus crop.  As this is being written, the reports are still conflicting as to whether or not any significant volume of either navels or Valencias will be suitable for the fresh market.  Too, there is also the question as to whether the trees were damaged enough to impact next season’s production.

This week, there were freeze warnings through much of Peninsular Florida, though cloud cover attenuated the minimum temperatures such that neither durations nor minima were sufficient to damage the crop.  Florida growers were concerned that previous weather had been so mild as to trigger the growth of a new flush, including flower buds.  Naturally, a new flush could be damaged at temperatures that are barely freezing.   Fortunately, it is sufficiently early in the season that should minor damage occur, the trees should be able to recover quickly and flush and bloom normally.

Locally, much of Texas had snow and/or icy weather, but all of the significant cold stayed to the north of the Valley.  That is not to say that the Valley did not experience freezing temperatures.  I have seen frost a couple of times last month, but neither time did it damage citrus trees.  Personally, I’m about ready for the Spanish daggers to bloom, as I have enjoyed about as much of this cold, drizzly weather as I can stand.

Speaking of drizzle, the total rainfall that my gauge at home in Weslaco has accumulated this month is 1.3 inches.  The gauge at the orchard northwest of La Feria had 1.1 inches for the month.  Not bad for January.

Of course, the ill wind that hit California groves resulted in tremendous price increases for oranges.  Higher consumer prices will benefit Texas and Florida growers, so long as the prices do not go so high that consumers quit buying.  California will soon exhaust its supply of citrus that was picked before the freeze.   

And I don’t even want to think about the Cowboys…


I offer my apologies if you tried to contact me during the recent cold weather scare that we had.  About mid-month, I managed to get so sick that I didn’t even argue when my wife took me to the hospital where I spent the next week plus.  Following that, I spent another week recuperating at home and I’m only working half days this week. Basically, I was knocked down by bronchitis and the flu on top of COPD (chronic obstructive pulmonary disease).


Assuming that the weather cooperates, it is time to start thinking seriously about grove care for the coming season.  Fertilizer applications are among the least expensive of all grove practices, and February is a good time to get the spreaders going.  It may be unnecessary, but I would remind you again that Rio Red grapefruit may benefit from split applications of nitrogen—depending on the amount of fruit that will be set.

While it is a bit early to make blanket conclusions about the overall volume of the current Rio crop, the estimate suggests that the next crop might be a little lighter.  If that is the case, the amount of nitrogen fertilizer this season should be reduced so as to preclude next season’s crop from having a bad case of sheepnosing.

If your grove was harvested a bit wet this last month, you may need to do some soil rehabilitation work as soon as it is sufficiently dry to allow it.  Deep ruts from the passage of heavy fork lifts are more than just unsightly and hard on grove equipment, soil compaction should be quite severe.  In such cases, the damage is worse than that which would be caused by the use of deep chiseling followed by disking.  In some cases, the soil isn’t rutted—it is just badly compacted.  Either way, I would be inclined to chisel those middles to avoid long-term consequences such as poor root (and tree) growth, increasing soil salinity, and other complications from soil compaction.

When everything else is caught up, the herbicide program should kick in to maintain the weed control that you already have.  In addition, any soil rehabilitation as described above will pretty well knock out the existing herbicidal control in the middles, so attention needs to be given to regaining control in that area.

Finally, it is not too early to think about the use of Temik in the grove.  Too many growers wait too long to apply Temik, but almost no one puts it out in February.  Basically, early application is far and away better than late application.  It may be that some growers just don’t feel comfortable putting Temik out until harvest is done, but Temik is not translocated into mature fruit, so there’s really no reason to delay so long.

The earlier Temik is absorbed into the tree, the sooner it goes to work controlling rust mites and other pests before they can migrate from the twigs onto developing fruit.

There is no claim (to my knowledge) that Temik controls flower thrips in citrus, but I cannot help but believe that the use of Temik before bloom will reduce their numbers and the damage that they do.  Our blossom thrips is not supposed to be the species that causes the “halo” scarring around the button, but the fact remains that we sometimes have some pretty severe scarring.


Believe it or not, the price of FCOJ has retreated from the $2.00 levels that have prevailed since early fall. The price is currently down in the $1.85 range.  The drop coincides with passage of this week’s freeze scare in Florida, but may also have to do with the fact that some of California’s freeze-damaged crop may be salvageable to juice.  As you know, California is in the fresh citrus business, not the juice business, so I am not really sure of the industry’s capacity to salvage fruit to processing.


Soon after the alarms sounded regarding the interaction between grapefruit juice and certain prescription medications, I suggested that perhaps researchers should take a look at using grapefruit juice as a means to lower the dosages (and costs) of some of these medications, thus keeping the other beneficial health effects of grapefruit juice and fruit available to consumers.

It is about to happen—at least in one instance.  Researchers at the University of Chicago are embarking on the first phase of a clinical trial to study the use of rapamycin—an anti-rejection drug used in kidney transplants—in combination with grapefruit juice in volunteers having advanced, malignant tumors (cancer).

You can read more about it at http://clinicaltrials.gov/ct/show/NCT00375245?order=1. The study involves a weekly dose of the med and two glasses of grapefruit juice daily.


Ph.D. Professor & Extension Horticulturist
2401 East Highway 83
Weslaco TX 78596


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