IN THIS ISSUE:

HIGHLIGHTS OF TPC, CITRUS SESSION
KATRINA
VALLEY CONDITIONS
VINE CONTROL PROGRESS
POTENTIAL CITRUS GREENING
ENVIDORŪ
2005-06


HIGHLIGHTS OF TPC, CITRUS SESSION-

The Citrus Session at this year's Texas Produce Convention was a most informative one and quite well-attended. Because the industry includes a whole lot of people who were not there, I'll recap some of the highlights.

The leadoff speaker (my apologies for having forgotten his nam-he's a Floridian who will be involved in the marketing of Texas citrus this season) told us that the number one growth product in fresh citrus in the US in the last five years is Clementins-small, easy-to-peel, seedless, with separable segments. Since Clementines are not seedless, he clarified that by stating that they are actually seedless mandarins that are marketed under the Clementine name. Doesn't say much for the future of grapefruit, as I think many of us understand after the slackening of demand over the last several years.

Florida reportedly lost nearly five million trees between 2001 and 20-that's considerably more than we even have in Texas. In fact, the grapefruit tree losses alone are about the same as our total citrus. And those data do not include losses, mostly to citrus canker-since last year.

We were also updated on the citrus canker situation in Florida by Dr. Parker of USDA, who collaborates with Dr. Gottwald in Florida. Of particular interest is one idea to combat the relatively slow removal of infected trees and all others within a 1900-foot radius-the idea is to kill the trees with diquat herbicide so that they will no longer be a source of inoculum, thereby preventing further spread while providing more time to remove the trees later.

Texas Department of Agriculture updated us on the Diaprepes citrus root weevil quarantine and eradication. Since its discovery in 2000 in Texas, it is still confined to approximately 10 acres of mostly residential property in north McAllen. It was pointed out that the weevil costs approximately $70 million annually in Florida. Unfortunately, eradication efforts in Texas are apparently insufficiently funded. Problem is, if Diaprepes is not eradicated, it will inevitably spread throughout the Valley and into other parts of the state, and will ultimately cost Texas many millions of dollars annually, as this is not just a citrus pest-it affects hundreds of species, including sugar cane, woody ornamentals and cotton.

Dr. Louzada updated us on his work with alternative citrus rootstocks. Most interesting to me was the Swingle "C-" stocks such as C-22, C-57 and C-146. These are not Swingle citrumelo, rather they are Swingle trifolia X Sunki mandarin. What is exciting is not only that these stocks appear to be adapted to Valley soils and conditions, but also that they are substantially more productive than sour. Current trials are located in both the western end of the Valley as well as the Mid-Valley. It doesn't take high math to understand that if you can produce more fruit for the same cost of production, you should be able to increase returns.

There were additional talks, but I don't want to make this too long.

KATRINA-

Florida's citrus industry got a glancing blow from Hurricane Katrina, but what she did to Louisiana, Mississippi and Alabama is almost beyond comprehension. A lot of folks in Texas have family and friends in the affected areas, some we have heard from, others have not been reached. We can only hope that they will be able to report in once communications and electric power are restored, which may take several days to several weeks. Others in the area are checking on their friends and neighbors, especially in small towns and rural areas where the restoration of phone and electric service is normally delayed until after larger cities and towns are back on line.

It is understood and accepted that while one downed line on a country road may affect service to a couple of dozen houses, one in town can affect several city blocks of houses or entire neighborhoods. This area of southeastern Louisiana and southwestern Mississippi is heavily wooded, so aerial utility lines are vulnerable to an awful lot of trees and/or tree limbs that cannot withstand winds such as accompanied the passage of Katrina. Hopefully, those unaccounted for are safe and are simply holed up with ample supplies of food, water and other necessities which they know from past experience to be necessary under such circumstances.

During the 60's, the same area was affected by at least three hurricanes that I recall. Each of those resulted in my mother having to dump our large deep freeze when the frozen foodstuffs began to thaw out after several days with no electricity. The water well got a good workout before the storm as they filled up practically everything that would hold drinking water. Hopefully, the younger generations learned from their elders and were as well prepared.

VALLEY CONDITIONS-

The Valley continues to experience very high temperatures as we move into September. Rains are still somewhat lacking, though severe storms have moved across the area during this week. But then, this weekend is the opening of whitewing dove season, so some kind of storms and rainfall almost had to occur this week to push many of them across the river! Too bad, as I had never seen so many whitewings as there were in the weeks after Hurricane Emily went through Mexico to the south of us.

Fruit size has begun to increase at last, and navel orange splitting appears to have subsided somewhat-though that could change with increased rain. Rio Red grapefruit shape is varied, with both normal looking fruit as well as some that does appear to be sheepnosed-but I haven't seen any significant numbers that appear to be severely sheepnosed.

VINE CONTROL PROGRES-

As you know, I have been working on the control of several vine species that are present in area groves. The end is not in sight but some of my recent tests are looking much better than anything that I have accomplished in the last couple of years of trying. With possum grape, I first broke them off below the canopy, and then treated the regrowth. Unlike in previous efforts, the treated growth yellowed, desiccated and died within about a week-and that is something I have never been able to achieve. Seedling possum grapes (those which had not yet begun to climb into the tree) under the canopy did the same. Directed sprays to milkweed vines (which pretty much stay on the ground) and goat's beard have also resulted in apparent death of the sprayed portions within a week.

I am waiting to see if the underground portion of possum grape sends up new growth-and I do expect that to occur with older, larger vines which have rather large underground storage organs. Then, I'll work on repeat applications necessary to kill it out. In addition, I hope to learn whether I can skip the initial breaking and just spray the bases of the vines.

One test is not enough, so additional tests were to be implemented this week-but were postponed on account of rain. It is still too early to discuss the materials that I am testing, but I did want to share my enthusiasm that there is reason to be tentatively hopeful. Once I figure it all out, including materials rates, then I can get down to economics.

POTENTIAL CITRUS GREENING-

Two trees in the Miami-Dade County area of Florida have been reported to exhibit symptoms that are common to citrus greening disease, which has never before been reported in the US. The primary vector is the Asian citrus psyllid, which arrived in Florida in 1998. Since that time, state and federal officials have been actively surveying citrus trees in certain targeted areas for the presence of citrus greening symptoms.

I reiterate that the suspect plants are just that-suspect. Samples are presently undergoing verification analysis in Beltsville, and the results should be known by early next week. We should all keep our fingers crossed, inasmuch as the psyllid has been in the Valley for a couple of years.

ENVIDOR-

I was talking with Steve Frazier earlier this week and he indicated that Envidor has been well-received by Valley growers, and that many growers are opting to hold off on its use into September or October when a final mite cleanup spray is required. He also indicated that its "rainfastness" is apparently better than what growers were told at Bayer's introductory luncheon back in July, i.e., that once it dries on the leaf or fruit, it will not wash off.

2005-06-

The first load hasn't been picked yet, but you can almost count on the papers to run a picture of orange harvesting somewhere in the Valley in the next week or so. And with that first harvest, the 2005-06 season will slowly begin to build momentum until it hits full stride by the first of November, weather permitting.

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


THE INFORMATION GIVEN HEREIN IS FOR EDUCATIONAL PURPOSES ONLY. REFERENCE TO COMMERCIAL PRODUCTS OR TRADE NAMES IS MADE WITH THE UNDERSTANDING THAT NO DISCRIMINATION IS INTENDED AND NO ENDORSEMENT BY THE COOPERATIVE EXTENSION SERVICE IS IMPLIED.


| Valley Citrus Notes Index | Aggie Horticulture |