SEASON ENDING
RAINFALL/WATER
BLOOM, FRUIT SET AND FRUIT DROP
GREENING AND CANKER
TRANSGENICS
PSYLLID SEARCH

SEASON ENDING-

The 2005-06 citrus season ended last month, but the final numbers from TVCC will not be available until later this week. Total grapefruit utilization through April 15 exceeded the crop estimate by a small percentage with approximately 195,880 tons, but that number could go a little higher when the final data are in. By comparison, the 2005 season produced 263,780 tons of grapefruit.

Early and navel oranges finished at 54,485 tons total in comparison to the previous year's total of 63,300 tons. However, despite the 14 percent drop in production, fresh utilization of all early oranges was roughly the same as in the 2005 season. Though shipments of earlies were down about 97,000 cartons, navel shipments were up by about 100,000 cartons, so the combined total fresh utilization was up just slightly (about 1.0 percent).

Valencias were at about 75 percent of the estimate on April 15, that is, at about 7,500 tons of an estimated 9,800 tons. By contrast, last season's Valencia crop finished at 11,300 tons.

Overall, it appears that the industry shipped about the same total volume of all citrus. The final volume last season was 8,168,953 carton equivalents; the April 15 total for this season was 8,128,432.

RAINFALL/WATER-

I've done everything I know that usually causes it to rain; played golf, gone camping, barbecued, washed the truck, irrigated (and irrigated and irrigated), watered the lawn (again and again), removed all wet weather gear from my truck, did a little bit of house painting, et cetera. Still, it just can't seem to rain, although it is rumored that a little rain might have fallen out to the west last week.

The reservoirs are showing the effect of the lack of rainfall, as the U.S. share of water in storage has fallen below 90 percent of Conservation Level, which means that we have used about a tenth of the water that was available at the beginning of the year. While most vegetables are finished now, overall water use in the Valley should continue at about the current level until sufficient rains come along-hopefully, we won't have to wait until September for that to happen.

Maybe somebody should plan a parade-

BLOOM, FRUIT SET AND FRUIT DROP-

The lack of consistently cool weather during the winter has resulted in some multiple blooms, which also means some later-than-normal bloom this spring (some trees were still opening flowers in late April). Still, it is too soon to tell the possible impact on fruit set for the coming season, as the final cycle of fruit drop usually does not end until the latter part of May.

Normally, a reduced crop in one season would be followed by increased production in the next season. Since overall production in 2005-06 (about 258,000 tons) was only about 76 percent of what was produced in 2004-05 (338,368 tons), we should expect production in the coming season to climb back above 300,000 tons. With adequate water, even without rains, fruit set should not be a problem. We'll just have to wait and see the effects of the multiple blooms on overall fruit set.

GREENING AND CANKER-

There have been a lot of meetings, discussion and work on Asian citrus greening and Asian citrus canker in the last month, and planning is on-going still.

In the meantime, fruit fly inspectors (those folks who check and service the various kinds of fruit fly traps that are in your orchards) are also looking for unusual chlorosis symptoms every time they inspect the fly traps.

Citrus Center personnel are checking local nurseries, and we are all looking outside the Valley for psyllids and the occurrence of any unusual symptoms.

The absolutely best scenario one could hope for is that 1) there is no greening (or canker) in Texas, and 2) there are no psyllids from Kingsville to Mississippi (or further). The simple fact is that without the psyllid, there is no greening, as the disease is self-limiting in the absence of a vector.

TRANSGENICS-

You might recall that Dr. Eric Mirkov's lab has some transgenic Rio Reds that may provide insect resistance with a lectin gene from snowdrop lily and citrus tristeza virus resistance with a coat protein gene from CTV. Now, Eric tells me that some transgenic work in his lab, in cooperation with some folks in Florida, with Rio, Ruby, Duncan grapefruit and Hamlin orange may have some promise for combating canker, greening (and greasy spot). The new work involves the bovine lysozyme gene and a spinach defensin gene.

Because we don't have either canker or greening in Texas, the challenge work will be carried out in Florida where both diseases are present. The greasy spot challenge work will be done here, since we have greasy spot.

Aside from the scientific effort involved in obtaining the transgenic plant materials (and proving that the genes were, in fact, successfully transcribed), there are other problems that sometimes seem insurmountable. First to be solved was appropriate authority to take the transgenic materials to Florida-on the one hand, the feds were highly involved because of restrictions on what can be done with transgenic materials and on the other hand, one cannot just move citrus plant materials from Texas (or elsewhere) into Florida.

Once those hurdles were cleared, both canker and greening are on Homeland Security's lists of bioterrorism agents, which requires researchers to obtain the appropriate permissions to even work on those diseases. Whether or not one sees it as fortuitous, the greening work apparently can now be carried out in the Fort Pierce area because the disease has been confirmed there.

"Challenge", by the way, is the procedures in which the transgenic material (and appropriate non-transgenic controls) is exposed to or inoculated with the disease organisms to ascertain whether the particular gene provides resistance to the disease(s).

PSYLLID SEARCH-

Dr. Vic French indicates that the team from the Citrus Center that went up to Uvalde and points in between a couple of weeks ago found psyllids everywhere except in the Carrizo Springs area. Samples were collected in Zapata, Laredo, Catarina and Uvalde.

There are several orchards in the Carrizo Springs area, but the team only went to the one which the late Floyd Everhard managed for many years. So, it cannot necessarily be concluded that there are no psyllids in Carrizo.

Tomorrow, they are going up to Port Aransas where Dr. John Fucik has arranged to show them around. Next week, they will be heading on to the Houston area.

Surprisingly, there have been no additional reports of psyllids outside the Uvalde to Kingsville to the Valley area, excepting the single report up in Cherokee County (and those were found on lemon trees in a retail nursery). On the one hand, that could mean that there are no psyllids in SE Texas; but it could also mean that the folks we are counting on to locate it may not be looking too hard. Hopefully, Citrus Center personnel will not find it from Corpus on into Houston on their upcoming reconnaissance trips over the next week.

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