Progress 10/01/98 to 06/30/05
Outputs
We have continued to evaluate 21 satsuma, 4 clementine and 2 tangerine selections at the Gulf Coast Research and Extension Center. This was the first year we had sufficient yield to adequately evaluate fruit quality, however, hurricane Katrina caused extensive wind damage on much of the fruit. The damage was characterized by individual juice sacs developing a whitish color and slightly dehydrating. There was no observable damage on the fruit skin. Wind gusts were between 60 to 70 mph during the storm. Fruit quality was determined on undamaged or slighly damaged fruit. Early maturing selections (with soluble solids to titratable acidity ratio > 8 at the end of october) included Armstrong Early, the chinese selection #9, Early St. Ann, LA Early, Okitsu Wase, Silverhill, Clemenules, and Marisol. Selections with 10:1 soluble solids to titratable acidity ratio included Armstrong Early, Early St. Ann, and Okitsu Wase. Peel color was most advanced on Armstrong Early, Chinese
selection #9, Early St. Ann, LA Early, and Okitsu Wase.
Impacts
The most widely planted satsuma mandarin cultivars in the southeastern US are Owari, and late maturing variety, and the early maturing variety Brown Select, which was not included in our study. Early maturing cultivars are highly sought by the commercial industry to broaden the marketing window. The cultivars and selections we are testing have demonstrated excellent and early internal quality, however, their is still significant green in the peel that would require degreening with ethylene.
Publications
- No publications reported this period
|
Progress 01/01/04 to 12/31/04
Outputs
The varieties in the field planting at the Gulf Coast Research and Extension Center in Fairhope, AL produced their first crop in 2004. There are 20 selections in the study, which was planted in 2001. Two clemenine selections (Algerian, Clemenules) and Dancy tangerine were the most precocious as indicated by highest yields (> 13 lbs/tree). Selections that produced moderate yields (2 - 6 lbs/tree) were Dobashi Beni, Kimbrough, Owari, China 9, Marisol clementine, GCS-1 Okitsu Wase, Brown Select, China 2 and China 6. Selections that produced very low (< 2 lbs/tree) or no fruit included LA Early, Port Neches, Early St. Anne, China 7, Silverhill, and Russia #1. Selections that produced average fruit size > 3.0 in. in diameter were Dobashi Beni, LA Early, Port Neches, Armstrong, China 9, Early St. Anne, Okitsu Wase, Brown Select and China 2. All other selections produced fruit < 3.0 in. in diameter.
Impacts
The 18 selections from China were made based on survival to a -12 C freeze and are expected to be more cold tolerant than the current commercial standard cultivar, 'Owari'. Some selections are also earlier maturing. The selections should reduce freeze risk and widen the harvest window than what currently exists in the satsuma mandarin industry along the northern coast of the Gulf of Mexico.
Publications
- No publications reported this period
|
Progress 01/01/03 to 12/31/03
Outputs
Only 4 of the 18 chinese Satsuma mandarin selections have been released from the Citrus Clonal Protection Program in Riverside, CA to date. Of the four released, two, C6 and C7, have been tested for their cold hardiness and compared to 'Owari' for acclimated (10C/4C) and unacclimated (30C/20C) potted trees. In laboratory tests under computer controlled conditions, C6 was more cold tolerant than 'Owari' by about 1 C, whereas C7 demonstrated similar cold tolerance to 'Owari'. Trees were planted in the field 2 years ago. Growth has been similar among the 4 selections and 'Owari'. There has been insufficient fruit to analyze quality.
Impacts
The 18 selections from China were made based on survival to a -12 C freeze and are expected to be more cold tolerant than the current commercial standard cultivar, 'Owari'. Some selections are also earlier maturing. The selections should reduce freeze risk and widen the harvest window than what currently exists in the satsuma mandarin industry along the northern coast of the Gulf of Mexico.
Publications
- No publications reported this period
|
Progress 01/01/02 to 12/31/02
Outputs
We are in the process of removing known viruses of 13 satsuma selections from China. Viruses are being removed using heat treatment and microtip grafting. To date, all selections have been treated with at least one of the techniques and we are currently testing the selections with indicator plants for the known viruses and suspected viroids. Of the 4 chinese selections that have been released from the Citrus Clonal Protection Program in Riverside, CA, we planted these selections along with 16 other named and numbered satsuma selections at the Gulf Coast Research and Extension Center in Fairhope, AL. in the spring of 2002.
Impacts
The satsuma mandarin selections from china were collected after surviving a freeze down to -12 C, which is significantly lower than the -9.4 C level of cold hardiness of current commercial cultivars. These selections should allow the gulf coast satsuma mandarin industry to be located farther north.
Publications
- No publications reported this period
|
Progress 01/01/01 to 12/31/01
Outputs
We have budded 20 selections of satsumas and other closely related citrus and will these will be planted in the field this spring. We have also recently obtained 11 selections of satsumas from the Citrus Clonal Protection Program from Riverside, CA. These selections were originally brought into th U.S. by us as part of this project. These selections contain viruses and are currently isolated from other citrus and closely related species at Auburn University. We plan to conduct heat treatment and shoot tip graftin to eliminate Citrus Tristeza Virus and viroids that were detected by the CCPP, which should take two years. These selections will then be field tested.
Impacts
The chinese selections of satsumas are more cold hardy, earlier maturing or have superior fruit quality compared to current commercial cultivars, and thus should improve the satsuma industry.
Publications
- No publications reported this period
|
Progress 01/01/00 to 12/31/00
Outputs
We received two of the satsuma selections from China and have propagated them on potted rootstocks. We received two more selections early this year and have propagated those as well. A trial with the four selections plus other named satsuma varieties will be planted at the Gulf Coast Research and Extension Center in Alabama this spring. We have conducted several studies to determine the best method of measuring cold hardiness in this study. We used cold-acclimated and unacclimated Owari in these studies and compared tree survival to electrolyte leakage, phenolic leakage, triphenyl tetrazolium chloride staining, callus formation of split stems, and watersoaking of leaves. The trees were exposed to decreasing temperature rates of 2 C/hr and whole plants removed from a computer-controlled freezer at every 2 C interval down to -12 C. An electrolyte leakage level of 50% was a suitable predictor of tree survival. This method will used during the winter months on the field
grown trees to determine differences in cold hardiness among the different cultivars. We also compared several microsprinkler head arrangements and water rates to determine the best method of protecting the variety orchard when planted.
Impacts
This study has been in implementation for only one year. The slow release of the satsuma selections from China has delayed planting the variety block. However, we have conducted studies that will better allow us to study these selections over the next several years.
Publications
- Monte L. Nesbitt, Robert C. Ebel, N. R. McDaniel, W. A. Dozier and D.G. Himelrick. 2000. Performance of satsuma mandarin protected from freezing temperatures by microsprinkler irrigation. HortScience, 35(5):856-859.
|
Progress 01/01/99 to 12/31/99
Outputs
We have just begun to acquire the chinese selections of satsuma orange from the USDA quarentine facility in Riverside, CA. We have also recently collected several named cultivars for evaluation including Clementine, Okitsu Wase, Kimbrough and selections to be released soon from the LSU breeding program.
Impacts
(N/A)
Publications
- Monte L. Nesbitt, Robert C. Ebel, N. R. McDaniel, and W. A. Dozier. 2000. Performance of satsuma mandarin protected from freezing temperatures by microsprinkler irrigation. HortScience, in press.
|
|