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NEW SEASON-NEW CHALLENGES
The 2000-01 Texas citrus season got underway in early September, and is fast approaching full-speed-ahead. While the estimated crop size is yet to be made public, most observers anticipate at least a modest increase over last season. As many growers learned, overall quality, especially in grapefruit, was not so good last season, particularly during the last half of the season.
The grapefruit juice market was perhaps better than anticipated-but it may have been too good, as Florida's grapefruit crop utilization was substantially above what had been anticipated. Undoubtedly, anticipated positive returns for processed grapefruit resulted in the harvest of groves that had previously been considered economically abandoned. That and lower than normal packouts in Texas have combined to dampen the processed grapefruit market for this season, as the market is resisting higher prices by reducing purchases.
Growers must do everything possible to maintain fruit quality as high as is economically possible-for both grapefruit and oranges, as the processed orange market is expected to be down substantially because of the anticipated record crop in Florida. Unfortunately, the late winter rust mite problem carried over into spring, resulting in grade-lowering blemishing before the weather cooperated with grower efforts to get the problem under control.
A DISCOURSE ON RETURNS-
Although most growers tend to look at returns in terms of dollars received per ton of production, you should be aware that processed grapefruit (until last season) has been a cost (i.e., negative return), Choice grapefruit has been barely above breakeven, leaving Fancy grapefruit to provide the only positive return. Since choice fruit contributes little to the bottom line and processed grapefruit losses are made up from the returns to Fancy, the price per ton is not so good as we would like to see.
The challenge, then, is to grow more Fancy fruit while also increasing the returns for Choice fruit and decreasing both the volume of and (usually) losses from eliminations. Given the vagaries of weather and pests, among other factors, the overall packouts may not be so easily improved.
Choice grade was adopted to signify a better quality than U.S. No. 2 in hopes of commanding a better price-although I doubt that many buyers accept the difference. In basic economics, supply and demand establish price. Obviously, if supply is higher than demand, prices fall-usually to a level that will increase demand. Equally obvious, we already produce more than enough Choice grapefruit-much more than we are able to market.
When a packinghouse cannot sell all of the Choice grapefruit it has, the unsold fruit has to go somewhere before it decays. That 'somewhere' is the juice plant. Since that destination has usually brought a negative return, it follows that the overall return per ton is also diminished in accord with how much Choice fruit is diverted. How much Choice fruit ends up at the juice plant? I don't know, but if my presumption (that Choice fruit returns are barely above the costs for pick-pack-and-sell) is valid, the percentage may be a third to half or more.
Back to the lesson in basic economics-are we asking to much for our Choice grapefruit? Would a lower price per carton boost demand volume sufficiently that overall returns would be improved from more cartons sold and fewer cartons diverted to juice? I don't know the answers; I only pose the questions as food for thought as we enter into the new season.
I have to updated the web listings for commercial packinghouses and gift fruit shippers. If you are in either category, you can help by going on line to http://aggie-horticulture.tamu.edu/citrus/market to check the accuracy of your listing. Notify me at email@example.com of changes or not.
Another pest has been discovered in Texas citrus-it still has not been positively identified, but all indications are that it is the citrus root weevil (Diaprepes). Its larvae feed along the bark of larger roots of citrus trees, opening the tissue to infections by Phytophthora. I expect that Dr. French and Dr. Skaria will have extensive discussions on this in the upcoming Citrus Center newsletter.
I've been called upon to examine a couple of Rio orchards exhibiting a significant droppage of mostly smaller than normal fruit. In most cases, the twigs on which such fruit are borne are either dead or dying-though some such twigs showed no evidence of dieback. Generally, the trees are quite large and exhibit what I would describe as significant deadwood inside the canopy. The location and amount of deadwood strongly suggest natural dieback from excessive shading, in part from the large tree size and thick canopy typical of Rio trees. Tree spacing and inadequate hedging/topping may also be involved. Diploidia twig dieback has not been ruled out. If you have the above symptoms, I would appreciate a call so that we can better define the problem and possible solutions.
The U.S.D.A will release its citrus crop forecast at 7:30 am CDT on Thursday, October 12.
The September rainy season did not materialize, making this about the second driest September of my 21 in the Valley. Without the rains, irrigation demand continues and reservoir levels are still dropping (about 32% of capacity). At this point, it looks like the new year will start with about the lowest volume of water in storage since the reservoirs were constructed.
Finally, there is some indication from Florida of California red scale populations flaring after some applications of NexterŽ (BASF). Phil Stansly described a field trial in Citrus Industry (Sept. 2000) on pages 25-26. The summary is that June and June plus September applications of NexterŽ resulted in significant populations of California red scale, while application only in September had essentially no impact on subsequent scale populations. I know that a lot of growers have used NexterŽ this season, so be advised to pay especially close attention to California red scale numbers right now.
I just received notice of a grower education seminar (and golf tournament) for Wednesday, October 4, at Cimarron Country Club in Mission starting at 8:30. The seminar is titled "Exploring Irrigation Water Supply Strategies" and features three speakers.
First, Bob Brandes will discuss the 1944 treaty and debt repayment status. That should really be interesting to those who heard the talk by John Bernal of the IBWC at the TPA convention.
Second is a strategy for agricultural water conservation for the next half-century by Guy Fipps. The final discussion explores the partnerships between municipalities and irrigation districts in California, by Kirk Dimmitt of the Metropolitan Water District of Southern California.
Registration for the golf tournament had to be in today (September 29), so it's already too late for those getting a hard copy of this newsletter.
CITRUS PEST UPDATE-
Citrus rust mites and California red scale continue at relatively low levels but most orchards have warranted or will warrant a spray application for either of these pests since the isolated September rains. Therefore, keep a careful eye if no spray applications targeted these pests in September. The citrus leafminer continues to increase in the new growth flushes but only on isolated small trees have they entirely damaged the new growth flushes.
Greasy spot and melanose problems have been a problem but has been less severe than last year. This may partially be due to the use of EnableŽ which has been under a section 18 for grapefruit. This section 18 expires on October 1, but it has been renewed by EPA for grapefruit for another year. Use on oranges was denied. It is recommended that copper applications be made in the spring for melanose and fungicide applications be made in the fall for greasy spot. This will also provide a rotational approach so these diseases do not become resistant to these products.
Melanose symptoms on leaves first appear as small, circular, dark depressions with a yellow margin. Later, these spots become raised and turn dark brown to black and they feel rough (sandpapery) to the touch. The fruit can also be affected with large areas of the fruit surface cracking in more or less irregular patterns, resulting in "mudcake" melanose. Greasy spot symptoms appear as large yellow spots which turn dark and appear slightly raised and greasy. Often this greasy symptom is observed on the underside of the leaf but can be found on the topside late in the infection process. Like melanose, it can also affect the fruit, causing a rind blemish consisting of black necrotic specks.
The problem with these diseases is that one fungicide application is not going to solve the disease problem immediately and indefinitely. These diseases have to be managed in a manner that incorporates a strategy that looks at the health of the trees for the next year or so. This may mean spring, summer and fall applications based on what you observe this year. It may also include a summer application of oil. Location and rainfall amounts also impact disease severity, which also should be factored in when deciding how stringent a disease prevention program is going to be needed to manage these diseases so they do not impact quality and production.
JULIAN W. SAULS, Ph.D.
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