Loading variety overview…
World of CitrusWorld of CitrusTroyer Citrange
University of California, Riverside — Citrus Variety Collection
https://citrusvariety.ucr.edu/crc1459 (opens in a new tab)
Accessed
The Mulberries · The Mulberries · 2025-12-20
https://www.youtube.com/watch?v=iTe5XvCuDCY (opens in a new tab)
Near-full auto-generated transcript reviewed with the matching scorecard archive. This citation supports only the presenter’s stated, unscored comparisons; it does not identify a current tree, prove a pedigree, or establish measured hardiness.
Accessed
Jim (Cloud Forest Gardener; embedded post #3) · UBC Botanical Garden Forums
The thread was started by SoCal2warm on March 27, 2019; the relevant passage is an embedded post by Jim (Cloud Forest Gardener), November 22, 2014, lines 215–240. Jim lists an own-root Troyer Citrange among five unprotected citrus that died during the winter discussed. The post also describes two 113-hour freezes in 2013–14, a December 2013 low of 10.8°F and a February event with three lows around 19°F, but does not tie the Troyer loss to one particular event or state the temperature at the tree. Jim says the Troyer was rootstock of a Kishu that died the previous winter; do not transfer that Kishu loss or exposure to Troyer.
Accessed
The Mulberries
https://themulberries.org/wp-content/uploads/2026/01/Troyer-Citrange.png (opens in a new tab)
Individual scorecard image for Troyer Citrange. The printed preference ratings are sweetness 5/10, sourness 3/10 and bitterness 7/10; the linked fruit reference preserves these original ratings alongside catalog numeric scores. Sweetness is stored as printed; sourness and bitterness use 10 minus the printed score. Any Brix or pH printed on the card is a separate reading, not derived from ratings. Sample method and harvest date are not stated unless noted in the reference.
Accessed
Israa Rifaat Khairi; Muhammad Abbass Salman · Diyala Agricultural Sciences Journal 8(2):58–71 · 2016-12
https://journal.djas.uodiyala.edu.iq/index.php/dasj/article/view/1524 (opens in a new tab)
The journal archive lists this 2016 study of in-vitro propagation of Sacaton citrumelo and Troyer citrange; its abstract reports both rootstocks separately. This source concerns tissue-cultured rootstock material, not orchard growth or Troyer fruit.
Accessed
L. D. Batchelor; W. P. Bitters · California Agriculture 6(9), printed pp. 3–4 · 1952-09-01
Reports California field plantings of named scion/rootstock combinations, not Troyer as a fruiting scion. Campbell Valencia on Troyer was described as more vigorous than the comparison stocks in 1944–45 plantings, with greater young-tree production and slightly larger fruit in the 1944 planting. A 1945 Fillmore Valencia planting on old citrus land reported more, larger and slightly better-quality fruit from Troyer-rooted trees than sweet- or sour-orange comparators. Monroe Lisbon growth on Troyer was similar to or slightly greater than sour orange; authors advised limited use and further Eureka-on-Troyer trials. Scan table OCR is unreliable; no numbers transcribed. These historic scion- and site-specific results do not establish generalized quick-decline resistance or Troyer fruit quality.
Accessed
S. Sen; V. Dhawan · Acta Horticulturae 839 (2009) · 2009
https://www.actahort.org/books/839/839_5.htm (opens in a new tab)
Abstract only; enhanced PDF/full paper not reviewed. Reports laboratory micropropagation of Troyer rootstock material from field-grown single-node explants, including 3.86 shoot-multiplication fold per four weeks, rooting on half-strength MS with NAA, 100% hardening survival, and DNA fingerprints consistent with stability of regenerated plantlets. This is propagation evidence, not orchard yield, scion performance, fruit quality or cold tolerance. Broad background comments in the abstract about tristeza resistance and acidic-soil adaptability lack a specific test design and are not recorded here as supported outcomes.
Accessed
K. Vinayak; D. J. Bagyaraj · Biology and Fertility of Soils 9 (1990):311–314 · 1990-08
https://link.springer.com/article/10.1007/BF00634107 (opens in a new tab)
Publisher abstract only; full paper is subscription access. It reports a screen of 18 vesicular-arbuscular mycorrhizal fungi with Troyer rootstock in unsterilized soil. Five named fungi gave the strongest reported growth and nutrition response; inoculated Troyer seedlings reached pencil-thickness for budding in about 13–14 months versus 18–19 months without inoculation. The abstract does not provide accession, replicate count, or sufficient growing conditions for orchard claims; no scion fruit was evaluated.
Accessed
Citrus ID, Edition 2 · 2011-10
https://idtools.org/citrus_id/index.cfm?packageID=1179&entityID=8879 (opens in a new tab)
General Citrus ID morphology fact sheet; no individual page author, accession, observation date, sample count or fruit-testing method is stated. It gives coded descriptions including compact/dense crown, glabrous first-year twigs, straight thorns, trifoliolate leaves, slightly rough/leathery rind, no navel, orange/yellow flesh and sour taste. Image captions identify pictured material as Riverside, but the page does not establish that all coded traits belong to one documented accession. Its taxonomic formulae and literature references remain attributed to the page; they do not replace the catalog’s named parentage.
Accessed
L. G. Weathers; E. C. Calavan; J. M. Wallace; D. W. Christiansen · California Agriculture 9(11), printed pp. 11–12 · 1955-11
Publisher article page rendered the full scan; supplied attachment 219071 was not directly accessible. Reports serious decline/disorder in Eureka lemon on Troyer, first detected in 1954 in a Ventura County experimental planting: heavy crop followed by yellowing/decline, disturbed and gumming bud union, and rootstock necrosis in some trees. Old-line and nucellar Eureka on Troyer were affected while the same tops on other stocks were not similarly affected. Wider affected lemon lines/sites are listed; cause remained undetermined and virus/incompatibility were hypotheses, not conclusions. Authors said Lisbon lemons and oranges on Troyer had not then shown the disorder. This qualifies compatibility only for the cited scion combinations and historical observations; it does not establish a general Troyer disease response.
Accessed
G. Conti et al. · Journal of Biotechnology 324 (2020):99–102 · 2020-12-20
https://www.sciencedirect.com/science/article/pii/S0168165620302467 (opens in a new tab)
Publisher abstract/highlights only. Describes transgenic Troyer rootstock lines engineered to constitutively express potato antimicrobial peptide Snakin-1 and challenged with virulent Xanthomonas citri. Detached-leaf and in-planta tests found fewer/smaller canker lesions in some lines; the page highlights reductions around 75% but does not identify the lines or expose underlying comparisons. This result concerns engineered lines and cannot be generalized to conventional Troyer resistance.
Accessed
Jean Marchal; Jacques Cassin; Pierre Martin-Prével · Fruits 30(5) (1975):329–337 · 1975
https://agritrop.cirad.fr/414588/ (opens in a new tab)
Agritrop metadata and French abstract only; supplied PDF timed out and article body was not reviewed. The title and abstract identify a Corsican Clementine leaf-mineral study including trees grafted on Troyer citrange alongside sour orange and Poncirus trifoliata. The abstract says mineral content varied with leaf age, climate and fruit load and identifies October as the most stable/reproducible sampling period; it supplies no rootstock-specific comparison values or effect direction. Cite only study participation and abstract context.
Accessed
Maria del Carmen Rivera-Cruz et al. · Terra Latinoamericana 38(3) (2020):519–528 · 2020
English publisher abstract only; linked article XML/full methods and results were not retrieved. Reports randomized greenhouse testing of Troyer rootstock seedlings across 14 fertilizer treatments with six replicates. The abstract reports particular soil and microbial changes under specified sugarcane-residue, manure and cachaza treatments; cachaza-1 at 2% increased mycorrhizal colonization and plant growth. Treatment-specific growth magnitudes and site details are not in the abstract. These findings do not establish orchard performance, fruit quality or cold tolerance.
Accessed
J. A. Menge; W. M. Jarrell; C. K. Labanauskas; J. C. Ojala; C. Huszar; E. L. V. Johnson; D. Sibert · Soil Science Society of America Journal 46(4) (1982):762–768 · 1982-07-01
Publisher abstract only; supplied PDF redirected to the abstract and full text was not retrieved. Greenhouse experiments report Glomus fasciculatus significantly increased Troyer seedling growth in 20 of 26 methylbromide-fumigated southern California citrus soils. The abstract also reports nutrient responses and correlations between mycorrhizal dependency and soil properties. This concerns inoculated seedlings/rootstock in greenhouse soils, not orchard yield, fruit quality, general soil recommendations or Troyer as a fruiting scion.
Accessed
The Mulberries · The Mulberries · 2024-11-21
https://www.youtube.com/watch?v=ti0ZfBFeVco (opens in a new tab)
Summary from transcript: In an English auto-captioned 2024 taste-test video, the speaker identifies the sampled fruit as Troyer citrange and describes very difficult peeling, moderate-to-high seed count, some juice, pale-yellow flesh, and sour, metallic, slightly bitter, woody/cardboard and floral/trifoliate flavor notes at the cited timestamps. He reports a sample mass of 65–66 g, unlike the 85 g printed on the existing Troyer scorecard; no explicit sample/card match was found. Spoken pH and Brix readings also overlap the card, but calibration/method and sample identity are unresolved, so they remain transcript context, not structured measurements. This is a single attributed tasting, not a cultivar-wide result; do not duplicate the existing scorecard ratings.
Accessed
M. Khelifi-Slaoui; N. Zianc; L. Khelifi · Algerian Annals of Agronomy 17(1):109–119 · 1996-06-01
https://asjp.cerist.dz/en/article/4304 (opens in a new tab)
Official ASJP landing-page summary only; the supplied direct PDF was blocked and full article unavailable. The English title spells the name Troyar; the summary and study context identify Troyer Citrange. Abstract-level methods concern in-vitro microcuttings from two-year-old greenhouse seedlings. Herbaceous microcuttings responded more than woody; the page summary reports 100% rooting with the M5 medium and 100% acclimation under its stated protocol. These are controlled plant-propagation findings, not orchard performance, fruit, or field hardiness.
Accessed
M. H. Edriss; D. W. Burger · Scientia Horticulturae 23(2):159–162 · 1984-06
https://www.sciencedirect.com/science/article/pii/0304423884900190 (opens in a new tab)
Publisher abstract only; full text was not retrieved. The abstract compares regeneration from Troyer epicotyl, root-meristem and root-segment tissues and describes hormone media used for shoot induction and rooting. Authors characterize the protocol as a rapid propagation method. This is controlled in-vitro propagation, not orchard/rootstock field performance or fruit.
Accessed
H. E. I. Yacoubi; A. Rochdi · Acta Horticulturae 911, paper 39; I All Africa Horticultural Congress
https://www.actahort.org/books/911/911_39.htm (opens in a new tab)
Publisher abstract only; exact publication date is not stated on the landing page. Selected Troyer callus lines exposed to increasing NaCl retained morphology and growth similar to control callus at 8 g/L NaCl, unlike sensitive wild-type calli. This is selected cell-line salt response in vitro and does not establish whole-plant or orchard salt tolerance.
Accessed
Ertuğrul Turgutoğlu; Şenay Kurt; Gülay Demir · Author-uploaded conference poster/full text, 30th ISTA Congress Seed Symposium · 2013-06
Author-uploaded conference poster text; peer-review status is not established. Its Troyer row reports 100% germination after two-day hydropriming or four-day osmotic priming of seeds with coats intact; the denominator is not stated. This is treated-seed germination evidence, not a general germination guarantee or fruit evidence.
Accessed
The Mulberries · The Mulberries · 2023-12-24
https://www.youtube.com/watch?v=70GS8zU0qno (opens in a new tab)
Summary from transcript: In an English auto-captioned video, the presenter identifies mail-order fruit as Troyer and reports low sweetness (‘pretty low’, 7:19–7:34), medium-high acidity (6:29–6:34), quite low flesh bitterness (6:38, qualified through 7:18), and juiciness (6:01–6:29). The captioned sample mass is uncertain (‘1005 G’); spoken 10.5 °Bx is unverified. These are attributed impressions of mailed fruit in a 2023 assessment with unknown tree, site, harvest date and maturity. The 2024 video is a later assessment; no direct pairing to the existing scorecard was established.
Accessed
Jagan Singh Gora; Ramesh Kumar; Brijesh Dutta Sharma; Chet Ram; Mukesh Kumar Berwal; Deepak Singh; Ram Swaroop Bana; Pradeep Kumar · South African Journal of Botany · 2022-01
https://www.sciencedirect.com/science/article/pii/S0254629921003598 (opens in a new tab)
The 2017–2019 Bikaner trial compared four rootstocks under Fremont mandarin scions. The abstract reports dwarfing of the Fremont scion on Troyer citrange. This is a graft-combination result, not a description of Troyer as a fruiting scion.
Accessed
Turgut Yeşiloğlu; Bilge Yılmaz; Berken Çimen; Meral İncesu · Turkish Journal of Agricultural and Natural Sciences · 2014
https://dergipark.org.tr/tr/download/article-file/142266 (opens in a new tab)
The paper reports a 2013 Adana trial using Henderson grapefruit as the scion on Troyer citrange, among five rootstock treatments. Trees were planted in 1997; six replicates per combination were used, with random samples of 25 fruit per tree at optimum late-November or early-December harvest. Results concern the Henderson–Troyer citrange graft combination, not Troyer citrange fruit or a universal rootstock trait.
Accessed
Dennis Peck · The Oregonian/OregonLive · 2022-01-13
The article’s “ONE GREEN WORLD FAVORITES” block says descriptions are from OneGreenWorld.com. The Troyer profile calls it a Washington navel/poncirus hybrid, more cold-hardy but less sweet than Washington navel, with lemon-like tart fruit said to remain edible; it advertises hardiness to at least 5°F and possibly lower once established. These secondary claims do not document an accession, field trial or cold exposure and are not new pedigree evidence.
Accessed
W. P. Bitters · Journal of Citrus Pathology (digital special topic) · 2021 (digital edition; manuscript circa 1986)
At printed p. 82 (PDF p. 88), Bitters summarizes Moreira et al. (1965), who placed Troyer Citrange among the “fair” rootstock drought-resistance group. The source describes nucellar Bara and Valencia Late orange, Dancy tangerine, and Eureka lemon scions budded on 77 tristeza-tolerant rootstocks under nonirrigated conditions in Brazil. It does not identify the accession or clone of any listed rootstock, provide a variety-specific sample count, or report a measured threshold.
Accessed
Sefa Polatöz; Murat Şeker; Çağlar Kaya · KSU Journal of Agriculture and Nature · 2025
https://dogadergi.ksu.edu.tr/en/pub/article/1475151 (opens in a new tab)
The study examined seedling populations from open-pollinated rootstock fruits collected in Adana, Türkiye. Two hundred seeds per rootstock type were sown and 100 seedlings per population were analyzed by flow cytometry. The authors report diploid genome sizes for all assessed populations. The study measured ploidy/genome size, not embryo origin or clonal identity, and does not establish a zygotic-seedling percentage.
Accessed