@Phlogopite
Looks interesting Satsuma, Xie Shan - Brite Leaf Citrus Nursery
Descriptions of new varieties recently distributed from the Citrus Clonal Protection ProgramToni Siebert, Robert Krueger, Tracy Kahn, John Bash and Georgios VidalakisThe Citrus Clonal Protection Program (CCPP)is operated through the Department of PlantPathology and Microbiology at University ofCalifornia (UC) Riverside and is funded in large partby The California Citrus Research Board (CRB). TheCCPP processes citrus propagative material in twophases. First, during the quarantine phase, citrus budwood of potentially important commercial varieties isintroduced from any citricultural area, germplasm orbreeding program of the world under the authority ofa permit which is issued to CCPP by the United StatesDepartment of Agriculture (USDA) Animal and PlantHealth Inspection Service in cooperation with the California Department of Food and Agriculture (CDFA).While in quarantine at the Rubidoux Facility in Riverside (approximately 2.5-3 years), newly imported varieties are tested extensively and any detected pathogens(such as viruses and bacteria that cause the tristeza,exocortis, stubborn, or Huanglongbing (HLB) diseaseof citrus) are eliminated via therapy. The second phaseincludes the production of budwood source trees whichare moved out of quarantine in Riverside and to theUC Lindcove Research and Extension Center (LREC)in Exeter, California, where the CCPP Protected Foundation (screenhouse) and Evaluation Blocks (field) arehoused. Trees established in the Evaluation Blocks areevaluated for trueness to type by scientists, growers,and nurserymen and are accessible to the public duringfield and fruit testing days (aka “walkthroughs”). Treesestablished in the Protected Foundation Blocks are offlimits to the public, they are regularly tested for a variety of pathogens and are registered with the CDFA asbudwood source trees.Over the past several years, many varieties havebeen through the rigorous “Variety Introduction-VI”disease testing and therapy program under quarantineat the CCPP. Varieties that successfully complete the VIprocess receive a unique VI identification number thatpermanently accompanies the budwood that is madeavailable to growers, nurseries, researchers, and others.Little information about many of the CCPP VI varieties is accessible to the public, or may take a great dealof effort to find. As a result, the UCR-Citrus VarietyCollection (CVC), USDA-National Clonal GermplasmRepository for Citrus and Dates (NCGRCD), and CCPPhave compiled information on the 18 most recently distributed varieties.20 CitrographMarch/April 2010Protected Foundation Block Budwood “Protected Foundation Block Budwood”is budwoodprovided from CDFA registered CCPP citrus trees from theLREC screenhouses and is available from the University ofCalifornia in accordance with the CDFA regulations for citrus registration and certification. Protected Foundation BlockBudwood is produced by trees grown in pots and in groundunder protective screen and is intended for individual nurseriesor growers to produce their own registered budwood sourcetrees or for the production of nursery increase blocks fromwhich additional budwood may be harvested in accordancewith CDFA (or other appropriate) regulations and used forthe production of certified nursery stock. A signed “Waiverand Release” form must accompany all orders for ProtectedFoundation Block Budwood. The “Waiver and Release” formis available on the CCPP website (http://www.ccpp.ucr.edu).SRA 337 or C54-4-4 Mandarin (VI 672):First distributionof buds from the CCPP: September 2009‘C54-4-4’ was selected for introduction to California in1997 by members of the California Citrus Nurserymen Society(CCNS) during a tour of the INRA-CIRAD Station de Recherches Agronomiques in San Giuliano, Corsica, associatedwith the Congress of the International Citrus Nurserymen’sSociety. C54-4-4 is actually a product of California, beinga cross of ‘Clementine’ X ‘Murcott’. The cross was actuallymade at the USDA Horticultural Research Laboratory in‘C54-4-4’ mandarin: Citrus Variety Collection, Riverside,California, 16 Feb 2010.Photo by T. SiebertOrlando, Florida, by Dr Phil Reece but the seeds were sentto Dr Joe Furr at the USDA Date and Citrus Station inIndio for testing and development. In 1963, budwood wassent from California to Texas for evaluation by Dr HeinzWutscher, USDA, Weslaco. The characteristics of ‘C54-4-4’under Texas conditions is presented in a paper in the Journalof the American Society for Horticultural Science, 103:124-127(1978). Those results indicate that ‘C54-4-4’ is a late maturingmandarin with uniform exterior color with 20 % granulation.The fruit was large with an average of 22 seeds per fruit. Brixwas intermediate in the varieties reported upon, but acid wasamong the lowest reported. Therefore, the brix/acid ratio wasthe second highest among the varieties evaluated. Yields wereintermediate. This data was based upon harvest in January orFebruary for the years 1969 – 1974. Dr Wutscher introducedthis selection into Florida when he transferred to Orlandoin 1975, and evaluated it in Florida conditions. In Florida, itproved susceptible to scab (a disease that we do not have inCalifornia). Dr Wutscher later made a scab-resistant selection of ‘C54-4-4’ that has recently been released by FloridaDivision of Plant Industry (DPI) as ‘Furr’ mandarin. Notethat this isnotthe ‘Furr’ trifoliate hybrid rootstock recentlyreleased by UC Riverside. In the 1980’s, prior to making thescab-resistant selection, Dr Wutscher sent budwood of ‘C54-4-4’ to Corsica. This is the source of the recent introductioninto California and hence doesnotrepresent the scab-resistantFlorida selection ‘Furr’.Imperial Mandarin (VI 684): First distribution of budsfrom the CCPP: January 2008‘Imperial’ is reported to have originated in Emu Plains,near Sydney, Australia, as a chance hybrid of ‘Mediterranean’or ‘Willowleaf’ and another mandarin, possibly ‘Emperor’ inapproximately 1890. ‘Imperial’ is one of Australia’s most important and long-established mandarin selections. It is widelyplanted throughout existing mandarin-growing regions, withabout 361,000 bearing and 26,000 non-bearing trees in 1999,mostly in Queensland. ‘Imperial’ is an extremely early maturing mandarin, equivalent in this regard to ‘Owari’ satsuma.Brix:acid ratio reaches 7:1 around mid-March in the earliestregions of Australia, with later regions reaching this ratio inearly June. ‘Imperial’ can be harvested up to July or Augustin Australia, depending upon the region. Fruit quality is considered good with a good balance of sugar and acid and goodinternal color. The skin is thin and soft, and although adherent,it peels easily. Juice levels are at least 35 % and fruit are firmwhen peeled. Granulation is sometimes a problem becauseof the low juice content. There are usually 4 or less seeds perfruit in both solid and mixed plantings. The fruit is mediumsized (or small in heavy crop years). The external color isyellow orange, but is more intense in regions where fall temperatures are cool. Fruit generally must be clipped from thetree rather than plucked. De-greening is necessary when fruitare harvested early and the post-harvest life is short at 2 - 4weeks. ‘Imperial’ responds poorly to heat and cold treatmentsfor pest disinfestation, which makes it unsuitable for export(from Australia). ‘Imperial’ performs adequately on a varietyof rootstocks, although incompatibilities have sometimesbeen noted on ‘Carrizo’ and ‘Troyer’. ‘Cleopatra’ produceshigh quality fruit. ‘Cleopatra’ and ‘Troyer’ are the most commonly used rootstocks in Queensland, whereas ‘Carrizo’ ismore popular in southern areas. There is a tendency towardsalternate bearing, which sometimes is managed by thinning.The tree’s habit is vigorous and upright. Cross-pollinators mayhelp with set, yield, and size. This variety is currently beingevaluated by Toni Siebert and Tracy Kahn. This informationwas summarized from The Citrus Industry, 1967, I:516; andSaunt, 2000, ‘Citrus Varieties of the World’, pp 65-66. A downloadable factsheet developed by Australian Citrus Limitedis available at http://www.australiancitrusgrowers.com.au/aspdev/resources/documents/ImperialB.pdfHickson Mandarin (VI 685):First distribution of budsfrom the CCPP: June 2008‘Hickson’ is reported to have originated near the town ofRoma, Queensland, Australia, as a sporting limb on ‘Ellendale’tangor. ‘Hickson’ is similar in many respects to its ‘Ellendale’progenitor. In Australia, it is a mid-season variety, maturingstarting in late June, about 2 weeks earlier than ‘Ellendale’.‘Hickson’ is considered to hang better than ‘Ellendale’, withthe harvest date extending through August. In August, it isusually slightly puffed but the juice content is satisfactory.Hickson mandarin: Citrus Variety Collection, Riverside,California, 16 Feb 2010.Photo by T. SiebertThe general appearance of the tree is similar to ‘Ellendale’,although there are some differences in leaf shape. The fruitis similar in appearance to ‘Ellendale’ but the rind is not assmooth and it peels more easily. The fruit averages 6 cm X 5cm, has a slight neck, and a smooth, yellowish-orange rind withsome gloss. The orange-fleshed fruit is juicy with good flavorand has 12-15 seeds. ‘Hickson’ is resistant to brown spot andwas initially considered a promising alternative to ‘Ellendale’.However, ‘Hickson’ declines when propagated on rough lemon rootstock probably due to genetic or physiological reasons.It is also susceptible to a crotch rot associated with Phomopsisand in addition does not perform well on trifoliate. For thesereasons, it is no longer as popular in Australia. This varietyis currently being evaluated by Toni Siebert and Tracy Kahn.Information summarized from: Jorgenson, 1972, QueenslandCitrus Bulletin, 1972:23-24; Cox, 1975, NSW Dept of Agriculture, Bulletin H2.2.6; Broadbent et al, Proceedings, ISC,March/April 2010 Citrograph 211978:207-208; Forsyth et al, 1985, NSW Dept of Agriculture,Agfact H2.1.4.). A factsheet developed by Australian Citrusunlimited is available at http://www.australiancitrusgrowers.com.au/aspdev/resources/documents/HicksonB.pdf.Sudachi Ichandarin (VI 693): First distribution of budsfrom the CCPP: June 2007Thought to be a hybrid of a papeda and a mandarin, ‘Sudachi’ arose as a chance seedling in the Tokushima Prefectureof Japan, on Shikoku island, where it has traditionally beengrown. When harvested young, ‘Sudachi’ is considered tohave a distinctive fragrance that is different from ‘Yuzu’. Theyoung fruits are used for cooking while still green, often beingincorporated into vinegars or flavoring many different entrees,especially fish. The flavor is now also used in soft drinks andalcoholic beverages. Fruit of ‘Sudachi’ was formally evaluatedby Ottillia Bier, Toni Siebert and Tracy Kahn in Septemberand October of years 2003 to 2007 at Riverside, California.Significantly smaller than ‘Yuzu’, the average fruit size has amean width of 3.8 cm and a height of 3.4 cm. The fruits have anoblate (spherical and flattened at both poles) shape, althoughsome fruits can be round. ‘Sudachi’ has a mean weight per fruitof 27.2 grams. Color break was reached between the first andthird week of September. The rind texture is slightly pebblywith a mean thickness of 1.9 mm. The number of seeds perfruit averages 9. The mean juice weight is 9.6 grams and theaverage juice content is 34.4%, which is fitting as ‘Sudachi’ isprimarily used for juice. The juice weight and juice contentincreased during the sampling dates. The internal flesh colorof ‘Sudachi’ in the green stage is light green to green-yellow.‘Sudachi’ is slightly more acidic than ‘Yuzu’ with an average of5% citric acid. ‘Sudachi’ trees tend to have a spreading habitof moderate vigor, but can be considered a small to mediumSudachi ichandarin: Citrus Variety Collection, Riverside,California, 15 Nov 2002.Photo by D. Karp.sized tree, as 26-years-old trees on Carrizo and C-35 citrangerootstocks are only approximately 8 feet tall, with no indications of rootstock-scion incompatibility. Thorns up to 5 mmin length are present in each leaf axil. Leaves are ellipticalin shape, with a small winged petiole. The tree canopy hasdense branching. (Kawada, K., and Kitagawa, H. “Storage ofSudachi (Citrus sudachiHort. ex Shirai) in Japan”. Pro. Int.Soc. Citriculture, 1084-1085. 1992. Kawada, K., and Kitagawa,H. “Citriculture, Marketing are Different in Japan”. FreshCitrus Fruits. Avi Publishing Company: Connecticut. 1986.)22 CitrographMarch/April 2010Australian Finger Lime (VI 697):First distribution of budsfrom the CCPP: June 2007The ‘Australian finger lime’, a citrus relative also knownasMicrocitrus australasica, is one of six different species ofcitrus considered to be native to Australia. This VI is one of 8different accessions ofMicrocitrus australasicain the CitrusVariety Collection, and was imported from Sydney, Australia,in 1965. Depending on the type of rootstock used (The CVChas used several: Schaub rough lemon, Cleopatra mandarin,Australian Finger Lime: Citrus Variety Collection, Riverside,California, 5 Dec 2008.Photo by D. Karp and T. Siebert.C-35 citrange, Carrizo citrange, Calamondin,Citrus macrophylla), the ‘Australian finger lime’ can be a very small (about5 feet on Schaub rough lemon) to large-sized tree. The leavesare tiny at approximately one-half inch long and the branchesbecome very dense and spiny with about 1 thorn set in everyleaf axil. New growth is purple in color and the one-quarterinch wide flowers are white and pink during the main floweringseason of February to April. The finger limes are about threeinches long and roughly the size of an average person’s indexfinger, but fruit from juvenile trees can be less than one inchlong. The skin of the finger lime is usually a greenish black tovery dark purple and thin, but durable. Once the fruit is cutopen the tiny round juice vesicles will slowly seep out of thefruit without squeezing, and resemble what we like to call“citrus caviar”. The round vesicles are usually a clear-green,but can be very light pink. The juice is very tart, much like aMexican lime. Although the tree produces fruit year round,the main fruiting season in California is November-Decemberwhen the fruit falls off in your hand. Australian finger lime isreported to fetch approximately 40-50 dollars per pound. Thefruits are technically edible, but this is not commonly done.Its most common use is as a garnish or flavor component inculinary creations.Persian Lime SPB-7 (VI 708):First distribution of budsfrom the CCPP: June 2007This selection of Persian-type lime is said to be free of thegenetic disorder called wood pocket, which is found in manyof the large-fruited acid limes. Wood pocket was formerly verycommon in Florida and caused extensive losses. The industryrequested help from researchers and after screening morethan 100,000 trees, 10 trees were identified that were apparently free of wood pocket, based upon their survival. Thecurrent selection (SPB-7) was entered into the program inPersian lime: Citrus Variety Collection, Riverside, California,3 Nov 2009.Photo by D. Karp and T. Siebert.1954 as Li-38-1-1-X. This selection was apparently erroneouslyidentified as being wood pocket positive and was dropped butlater reinstated and never showed wood pocket symptoms. Thecurrent selection was entered into the Florida DPI foundationprogram about 1961 and was imported into California in theyear 2000. The current screenhouse bud source descendedfrom a tree planted in the Haines City Foundation Grove.Because of this budsource, the Florida Persian lime industrybecame virtually free of wood pocket by the early 1970s. (Thisinformation redacted from an email from Mike Kesinger,06/25/2006) Trees of this selection have been planted at variousplaces in California for evaluation as to the development ofwood pocket. One of these locations is the Coachella ValleyAgricultural Research Station in Thermal, CA. Since woodpocket develops more rapidly at high temperatures, the treesin Thermal should be the most susceptible to development ofwood pocket. More information on these observations will beprovided as it becomes available.Lemonade (VI 734): First distribution of buds from theCCPP: September 2008‘Lemonade’ is reported to be a sweet lemon hybrid of unknown parentage with a very pleasant taste, and can be readilybut not easily peeled. The fruit is small-medium, and not veryseedy. The trees are semi-dwarfed (on trifoliate rootstock), butquite productive. The main crop matures in early spring in NewZealand, with much smaller summer crops also occurring. Unfortunately there is no commercial production in New Zealand,although it is a popular home garden tree. It is susceptible tocitrus scab disease; however, in a drier climate this should beless of a problem. (This information redacted from an emailfrom Andrew Harty via Peter Chaires, 12/07/2005) Althoughthe budsource trees are derived from trees at the CCPP thattested negative for all known graft-transmissible diseases,trees of ‘Lemonade’ propagated in Riverside have shown atendency to develop small brown to black lesions on the bark.The reason for these lesions is currently unknown. ‘Lemonade’trees propagated at Riverside are not particularly vigorous butthe relationships of this to the observed lesions is not known.Lemonade: Citrus Variety Collection, Riverside, 3 Nov 2009.Photo by D. Karp and T. Siebert.Early Release Budwood“Early Release Budwood” is budwood provided from selected cultivars that have been recently out of quarantine andare maintained by the CCPP at the LREC Protected Foundation Blocks for the “Early Release” program. These cultivarsare grown in pots under protective screen producing limitedamounts of budwood. Therefore, supply of Early ReleaseBudwood will be limited. A signed “Waiver and Release” formmust accompany all orders for Early Release Budwood. The“Waiver and Release” form is available on the CCPP website(http://www.ccpp.ucr.edu).Valentine Pummelo Hybrid (VI 597): First distribution ofbuds from the CCPP: September 2009‘Valentine’ is the most promising of the seedy pigmentedlow-acid pummelo hybrids selected by Drs. Soost and Cameron in 1986 from a cross of ‘Siamese Sweet’ pummelo xValentine pummelo hybrid: Citrus Variety Collectionlaboratory, Riverside, California.Photo by O. J. Bier.March/April 2010 Citrograph 23(‘Ruby’ blood orange x ‘Dancy’ mandarin). It received itsname from former Staff Research Associate for the CitrusVariety Collection Ottillia ‘Toots’ Bier, who nicknamed it‘Valentine’ not only because the fruit matures in mid-Februarynear the Valentine’s Day holiday, but also because often whenthe fruit is cut lengthwise and turned upside down, the fleshof the fruit resembles a vibrant red heart. ‘Valentine’ fruitsare round to somewhat pyriform (pear-shaped). The averagefruit size is large with a mean width of 10.8 cm (4.25 inches)and a height (including the neck) of 11.0 cm (4.33 inches).The mean weight per fruit is 531.1 grams (18.7 ounces). Rindcolor is medium to dark yellow. The rind texture is moderately smooth with a mean thickness of 8.8 mm (0.35 inches).Fruit samples from Lindcove generally have a thicker rindthan samples from Riverside. The number of seeds per fruitaverages 27.6. However, the mean number of seeds per fruitamong 36 different 10-fruit samples ranged from 2.6 seedsper fruit to 51 seeds per fruit. The mean juice weight is 201.8grams (7.1 ounces) and the average juice content is 38.6%.The red flesh color of ‘Valentine’ can be somewhat variablein its distribution and intensity inside the fruit. Color formation first appears in mid-January and becomes more intensein early to mid February when the solids to acid ratio is anaverage of 16:1. Please see “’Valentine’, A Recently ReleasedAnthocyanin-pigmented Pummelo Hybrid Developed at UCRiverside” from Topics in Subtropics, 2009, 7(3): 2-4, for amore detailed description of this variety.Xie Shan Satsuma (VI 621): First distribution of buds fromthe CCPP: June 2007‘Xie Shan’ was originally imported from the Institute ofSubtropical Crops of Zheijiang Academy in China in 1992.Dr. Fred Gmitter, University of Florida, who was responsiblefor the collection of this variety, reported Xie Shan to be“extremely early ripening in comparison to other Chinesesatsumas”. In a California trial, Dr. Thomas Chao, UC Riverside, reported that ‘Xie Shan’ developed high brix levelssomewhat earlier than other early Satsuma cultivars tested(‘Armstrong’, ‘Miyagawa’, and ‘Chinese S-9’). However, highacid levels kept the sugar/acid ratio within about the samerange as the other cultivars. ‘Xie Shan’ and ‘Miyagawa’ wereconsidered the earliest cultivars in this trial. Additionally, itwas reported that ‘Xie Shan’ was completely seedless, easypeeling, and had a unique taste and flavor. Projected harvestin the San Joaquin Valley was mid-September. (Informationfrom Topics in Subtropics, 2005, 3(2): 3-5). This variety is currently being evaluated by Toni Siebert and Tracy Kahn.China S-9 Satsuma (VI 636):First distribution of budsfrom the CCPP: June 2007‘China S-9’ was part of the first of two different sets ofseveral satsumas collected in the Hubei Province of China,by Dr. H. Huang, Auburn University, in 1995 and given to theCCPP for introduction and quarantine. Each selection in thefirst set was given the “S” signifier and a number, and wasdescribed in a letter from Bill Dozier, Auburn University, tothe late Dave Gumpf on August 28, 1995. They were selectedfrom fields in Hubei and Sichuan that had been devastatedafter a very bad freeze. Each selection was from brancheson satsuma trees that had survived the freeze, and the threeselection characteristics they looked for were cold hardiness,fruit quality and tree vigor. Huang rated the tree vigor andfruit quality of ‘China S-9’ as ‘acceptable’, and cold hardinessas ‘good’. The second set of satsumas were brought back byDozier in either 1996 or 1998 after he visited these same areasof China where the freeze occurred. Preliminary observationsby Thomas Chao at Santa Paula (see citation in previous description) suggested that ‘China S-9’ should mature early inthe San Joaquin Valley (about the same time as ‘Miyagawa’and ‘Xie Shan’). In addition, preliminary observations atLREC showed that ‘China S-9’ has a smoother peel than mostother satsumas. This variety is currently being evaluated byToni Siebert and Tracy Kahn.Pehrson #3 Valencia Orange and Pehrson #4 ValenciaOrange (VI 749 and VI 750): First distribution of buds fromthe CCPP: September 2008These VI’s are two of a group of 8 Valencia clones selected by University of California Cooperative ExtensionSpecialist Emeritus John Pehrson. These were included in aValencia Strain Trial established at LREC. In a letter sent byJohn Pehrson on April 13, 2009, to the CVC, he described theXie Shan satsuma: Citrus Variety Collection, Riverside,California, 27 Nov 2007.Photo by T. Siebert.24 CitrographMarch/April 2010China S-9 satsuma: Citrus Variety Collection, Riverside,California, 27 Nov 2007.Photo by T. Siebert.complex history of the Valencia clones. The objective was tosalvage propagative material from high production Valenciatrees of good quality fruit because urban growth was shrinkingValencia acreage in Orange County, CA. Some of the strainswere reported to be from the Smith Family Ranch and theWagner Family Ranch in Placentia, CA, and the Gilman Grove,Fullerton, CA. Seedlings were grown from collected fruits andbudded onto Troyer citrange. These were planted in cooperation with a grower in a Brea area oil lease that would not lastanother 15 years. The time frame was from the late 1950’s to themid 1960’s for collection, growing and planting. Shortly afterplanting in Brea, Pehrson was moved from Orange County toTulare County, so efforts were made to save these selections.With propagating material from the plot Pehrson had established with the grower in Brea, CA, Ed Nauer cleaned up 8 ofthe clones in Riverside, CA, and moved them into a Valenciastrain trial at LREC in 1986 where they were compared withCampbell, Cutter, Frost, Olinda, and Chapman Valencias. The8 Valencia clones were put through the VI index as VI’s 747 to754 with budwood taken directly from the nucellar block inNovember 2006. ‘Pehrson Valencia #3’ and ‘Pehrson Valencia#4’ were selected as being the most promising out of the 8clones. ‘Pehrson Valencia #3’ was selected for having good peelcolor, minimal regreening, having a good yield, and is latermaturing. ‘Pehrson Valencia #4’ was selected as having thehighest cumulative yield and weight, and a good distributionof fruit size (information from M.L. Arpaia).FairchildLS Mandarin (VI 762):First distribution of budsfrom the CCPP: January 2010‘FairchildLS’ is an irradiated selection of ‘Fairchild’mandarin developed at UC Riverside. The distinctive traitof ‘FairchildLS’ is that it is considered to be low seeded (2.4seeds per fruit) despite any cross-pollination. ‘FairchildLS’fruit are deeply oblate in shape with no neck. The fruit ismedium sized for a mandarin (classed as Large by State ofCalifornia standards) averaging 64 mm (2.5 in.) in diameterand 56 mm (2.2 in.) in height with a very smooth, deep orangerind color. The rind is relatively thin and at maturity is considered moderately easy to peel. The fruit interior has fine fleshtexture with 10-11 segments. The fruit are juicy averaging 47%juice with an average weight of 110g. ‘FairchildLS’ matures inwinter (late January) and holds its fruit quality characteristics through late March. Fruit from trees on Carrizo citrangerootstocks average 12.1-13.0% soluble solids and 0.85-1.17%acid in January increasing to 13.2-14.5% soluble solids withdecreasing acid of 0.76-0.93% by mid-March at four triallocations. Fruit from trees on C-35 citrange rootstocks average 11.2-12.8% soluble solids and 0.94-1.23% acid in Januaryincreasing to 13.1-14.0% soluble solids with decreasing acidof 0.78-1.01% by mid-March. ‘FairchildLS’ averages 2.4 + 0.6seeds per fruit in the presence of cross-pollination at all triallocations throughout California compared to 15-25 seeds perfruit for regular ‘Fairchild’. Pollen of ‘FairchildLS’ has verylow viability, therefore it has a very low likelihood of causingseeds in other citrus, particularly mandarins, when plantednearby. Fruit production for ‘FairchildLS’ begins in the thirdyear after planting. Four-year-old trees averaged 62-88 lb,and five year old trees averaged 92-108 lbs. Alternate bearingcan be a problem by years seven and eight (information fromM.L Roose and T.E. Williams). Patent and/or propagationFairchildLS mandarin:Photo by M. Roose.rights for Fairchild LS Mandarin are held by the Regents ofthe University of California. Budwood is available only tonurserymen who have a License Agreement for these cultivars.Tango Mandarin (VI 765):First distribution of buds fromthe CCPP: June 2007Tango is a patented (Plant Patent #17863) irradiated selection of W. Murcott mandarin developed at UC Riverside. Fruitof ‘Tango’ are similar to W. Murcott in all appearance, qualityand production characteristics with the exception of seednumbers. ‘Tango’ fruit are deeply oblate in shape with no neck.The fruit is medium sized for a mandarin (classed as Large byState of California standards and size 28 by industry packingstandards) averaging 59 mm (2.32 in.) in diameter and 48 mm(1.89 in.) in height with a very smooth, deep orange rind color.The rind is relatively thin and at maturity is easy to peel. Thefruit interior has fine flesh texture with 9-10 segments and asemi-hollow axis of medium size at maturity. The fruit are juicyaveraging slightly over 50% juice with an average weight of90.6 g (3.2 oz.). ‘Tango’ matures in winter (late January) andholds its fruit quality characteristics through April into May.Production is excellent averaging 800-900 cartons/acre whenplanted at densities of 250-300 trees/acre. Fruit from treeson Carrizo and C-35 citrange rootstocks average 11.1-13.1%soluble solids and 0.97-1.19% acid in January increasing to13.5-15.4% soluble solids with decreasing acid of 0.54-0.82%Tango mandarin: Citrus Variety Collection, Riverside,California, 21 Feb 2007.Photo by D. Karp.March/April 2010 Citrograph 25in April. ‘Tango’ averages 0.04 + 0.2 seeds per fruit in the presence of cross-pollination at seven trial locations throughoutCalifornia compared to 11.6-22.6 seeds per fruit for W. Murcott.Pollen of ‘Tango’ has very low viability consequently it has avery low likelihood of causing seeds in other citrus, particularlymandarins, when planted nearby. Like ‘W. Murcott’, trees of‘Tango’ have a tendency to overbear and therefore need to beregularly pruned to maintain good, but not excessive production and to maintain fruit size and prevent alternate bearing.Crop yields should be limited to about 150-170 lbs/tree (6-7mandarin boxes) through a combination of pruning and, ifneeded, fruit thinning and should be harvested on time, not lefton the trees as this can lead to alternate bearing (informationfrom M.L Roose and T.E. Williams). Patent and/or propagation rights for Tango Mandarin are held by the Regents ofthe University of California. Budwood is available only tonurserymen who have a License Agreement for these cultivars.Primosole Mandarin (VI 777):First distribution of budsfrom the CCPP: September 2009‘Primosole’ mandarin is a hybrid of ‘Carvalhais’ mandarinand ‘Miho wase’ Satsuma produced at the University of Catania, Sicily, in 1980. It is described as being seedless in isolationand matures very early (at the beginning of October in southern Italy or early April in Australia). Coastal FruitgrowersNewsletter (Australia, August 2005) reported, upon release of‘Primosole’ from quarantine, that it reached maturity about10 days before Okitsu satsuma. Fruits are oblate in shapeand average 150 grams in weight in southern Italy. The treesare said to be vigorous and productive with an open growthhabit. They do not exhibit alternate bearing tendencies. Thebranches do not have spines, and the lanceolate (long, widerin the middle or lance-shaped) leaves tend to fold as if underwater stress. According to an article published in Plant Disease,December 2001, pg. 1291, called “Extreme Susceptibility of Primosole Mandarin to Alternaria Fruit Rot in Italy”, ‘Primosole’is extremely susceptible to Alternaria fruit rot due to growthcracks at the stylar end (blossom end of fruit) and sensitivityto sunburn. Citrogold reports that this variety has orange rindcolor, a good to large fruit size, and a good to very good cropload. The peel separates easily. The flavor is said to be betweensatsuma and mandarin. The variety handles degreening well,stores well, handles cold sterilization well, and has a firm rindin comparison to satsumas. It tends to have a ricyness in thecore of the fruit that lessens with tree age and characteristicleaf wilting. ‘Primosole’ is a self-incompatible variety, but willpollinize compatible varieties such as clementines. Cross pollination is managed by a buffer of 10 rows. It does not requirea plant growth regulator to increase fruit set or size. It is verysensitive to strong winds and can defoliate under windy conditions. Swingle is reported to not be suitable as a rootstockfor ‘Primosole’ mandarin, but it does well on C-35, Carrizo,and Troyer citranges. (Aznar and Fayos, Citricos. Variedades ytecnicas de cultivo. Mundi-Prensa Libros. 2006. pg 128)Bitters C-22 Citrange (VI 792), Carpenter C-54 Citrange(VI 793), and Furr C-57 Citrange (VI 794): First distributionof buds from the CCPP: September 2009According to the report provided by Claire Federici,Ricarda Kupper, and Mikeal Roose, “‘Bitters’,‘Carpenter’and ‘Furr’ trifoliate hybrids: Three New Citrus Rootstocks”26 CitrographMarch/April 2010(information can be found at BPSC Faculty | Department of Botany & Plant Sciences), all threeare hybrids ofCitrus sunkiand Swingle trifoliate orange.John Carpenter and Joe Furr made all three hybrids as partof the USDA breeding program at Indio, CA. Professor W.P.Bitters tested the hybrids for Citrus Tristeza Virus tolerancein a trial established at the South Coast Research and Extension Center in Irvine, CA, in 1966 and 1968. All three hybridsshowed good tolerance to the virus. Details about subsequentfield trials, soils, management, and results compared to othervarieties can be found at http://plantbiology.ucr.edu/faculty/Summary-of-Active-Rootstock-Trials-5-09v5.pdf• ‘Bitters’ produces a small tree, with high yield per canopyvolume. Young trees on this rootstock showed good toleranceto freezing. Fruit quality of late navels was good and granulation was no worse than fruit on ‘Carrizo’ or ‘C-35’. It is tolerant to CTV, moderately tolerant ofPhytophthora parasitica,not very tolerant of citrus nematode, and very tolerant ofcalcareous soil. It was reported that this rootstock is the bestcandidate in Texas to replace sour orange due to its toleranceof calcareous soil conditions.Bitters C-22, Carpenter C-54, and Furr C-57 citrangerootstocks:Photo by M. Roose.• ‘Carpenter’ produces medium to large trees, with goodyield. Young trees on this rootstock showed moderate tolerance to freezing. Fruit quality of late navels was good andgranulation was no worse than fruit on ‘Carrizo’ but wasslightly worse than on ‘C-35’. It is tolerant to CTV, moderatelytolerant toP. parasitica, very tolerant of citrus nematode, andmoderately tolerant of calcereous soil.• ‘Furr’ produces medium to large trees, with good yield.Young trees on this rootstock showed good tolerance to freezing. Fruit quality of late navels was good and granulation wasno worse than fruit on ‘Carrizo’ or ‘C-35’. It is tolerant to CTV,very tolerant toP. parasitica, very tolerant of citrus nematode,and moderately tolerant of calcareous soil.Please visit the Citrus Clonal Protection Program websiteat http://www.ccpp.ucr.edu for more information about howto obtain budwood of these varieties. Registered users of theonline budwood ordering system may visit CCPP - Budwood. If you are not a registered useryou can e-mail ccpp@ucr.edu with your name, address, e-mail,and phone number or call (951) 684 8580 and the CCPP willgenerate a username and password for you. After becoming aregistered user of the budwood ordering system you will alsoreceive announcements about fut
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