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Rainfall in June was welcome indeed. Although the amounts were widely variable, most groves apparently received at least some rain during the month. Very few groves, however, were blessed with sufficient rainfall to postpone irrigation more than a week or two.
Inflows into the reservoirs have more or less kept pace with releases, as some good rains did occur in the Big Bend and downstream. That plus the reduction in irrigation demand in the Valley (partly because of rain and partly because grain sorghum and corn harvesting commenced in June) combined to maintain reservoir levels at about 34 percent of conservation capacity at the end of the month. That level is significantly greater than it has been at this time in recent years.
The tropical storm season is underway with two storms already having been named. TS Bill formed quickly last week in the western Gulf and moved into Louisiana, dumping heavy rains there and along its northeasterly pass through the South. We would like a similar storm to track along the Rio Grande producing lots of rain without the hurricane-force winds.
Meanwhile, July started with lots of clouds and plenty of "light
and sound", but little general rains. The chances for "pops" to
continue daily into next week are favorable, so let's hope these thunderstorms
"pop" where the rains are needed the most.
The citrus canker situation just doesn't seem to get any better-cutting and removal of trees in the buffer areas around canker-infected trees is on a roller coaster of on-again, off-again because of court orders. As June ended, a Broward Circuit Court was being petitioned for a temporary injunction to halt planned efforts by the state to remove approximately 200,000 citrus trees in Dade, Broward and Palm Beach Counties. Meanwhile, new finds seem to keep popping up more or less at random, the latest being in the Immokalee area and in Boynton Beach.
Meanwhile, suspected Mexican fruit fly larvae were detected in May in peppers imported from Mexico into Pinellas County.
And the Diaprepes root weevil, which is still under quarantine treatment in a confined McAllen area where it was detected a couple of years ago-costs Florida growers an estimated $150-200 per acre per year to combat with insecticides and parasitic nematodes. Because eradication of this pest in Florida is not going to occur, this additional cost is an ongoing one. Think about that when you wonder about the efforts currently underway in Texas to eradicate this pest.
For the most part, summer rains have been abundant throughout the Florida citrus belt; with too much rain in only a few areas. Overall, reports are that the groves are in good condition with good fruit set, which latter is to be expected after last season's short crop.
The generally cloudy, sometimes rainy, weather of recent weeks has contributed to citrus rust mite population increases in groves across the Valley. Close monitoring is essential to determine the need for control before economically damaging levels occur.
I was recently called out to look at a heavy infestation of leafhoppers in a grapefruit orchard. I had never seen such numbers of mature leafhoppers. Sooty mold was abundant on the leaves and fruit, but not so severe as is observed with blackfly infestations. Leafhopper is considered to be a minor pest-unless it's in your orchard. The adults hatch in spring from overwintering eggs, then persist into September-usually only the one generation per year. Chances are that if you have them once, you'll have them again the next year unless you can break the life cycle and allow biological controls to regain the upper hand. A number of insecticides will control the adults, but a better approach may be to shoot for control of both adults and their eggs. To that end, materials to be used in the normal summer spray should be chosen based on this and other pest control needs. As a rule, citrus spray oil is still one of the best materials to include in the summer spray; and it is a pretty good ovicide.
The sapote fruit fly quarantine ended in June, as no new detections occurred. Hopefully, that's the end of our problems with this pest.
Irrigation, weed control and the summer spray program are the major grove operations currently underway. Irrigation, of course, varies with rainfall, which has been less than plentiful. Weed control includes spot treatments for escapes, and some growers apply a second round of pre-emergent herbicides during the summer. Too, some growers are forced to spend money on vine-pulling operations.
Vine control has moved to the forefront of weed control problems in the last several years, which leads me to question why this is so. In general, it appears that the current selection of herbicides has proven very effective in reducing traditional weed control problems over the last several years. As is usually the case, about the time you achieve control of most problem weed species, something else emerges to problem status, in part because of the success of the herbicide program (which eliminated competing vegetation). In our case, the new problem is vines.
Control of vines is difficult, at best systemic, non-selective herbicides don't work on some species (such as possum grape). Vines such as goat's beard, on which these materials are effective, are hard to control because you can't just go out and spray the entire canopy of a vine-covered tree the vines first have to be cut off below the canopy, with treatment (and re-treatment!) of the regrowth before it climbs back into the canopy.
Though I could be mistaken, I recall only one citrus herbicide label that lists any of our four major vine species milkweed vine is listed on the Krovar I label. Krovar I is a combination of equal parts of Hyvar and Karmex, neither of which lists milkweed vine. Milkweed vine was once listed as susceptible during the seedling stage to Krovar, Hyvar and Karmex. Morningglory (moonvine) was once listed as partially susceptible to Krovar and Hyvar.
In any case, Krovar and Hyvar were generally considered to be somewhat effective in suppressing most vines when used regularly in the citrus herbicide program. I do know that vine problems have increased in groves in which Krovar or Hyvar has been replaced by other herbicides. While I am not necessarily advocating these materials to the exclusion of other herbicides, I would ask that any grower who used to use these products regularly, as well as those who still do, give me a call to discuss your experience with vines. Perhaps the weight of such anecdotal evidence, coupled with the results of current vine control tests, will suggest a better course of action in the future.
The Texas Citrus Growers League has scheduled its annual meeting for next Thursday, July 10, at noon in the Rio Red Room of the TAMU-K Citrus Center. You must RSVP to 956/584-1772 if you plan to have lunch at the meeting-without a reservation for lunch, you may as well wait until 1:00 to show up!
The notice for the lunch and meeting also included a dues invoice for the coming season-no increase there, and the form and instructions for the annual Citrus Price Survey. I know that the League would like to report the results of the Price Survey for the 2002-03 season at this meeting, so make every effort to return the survey form before the end of this week.
I'll see you there.
JULIAN W. SAULS, Ph.D.
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