1. Classification and Cultivars

4. Leaf Morphology

5. Two Tribes Clauseneae Citreae has 3 Subtribes Triphasiinae
Balsamocitrineae
Citrinae
The Citreae tribe consists of primitive citrus relatives and true citrus relatives
CSubtribe: Citrinae
Citrus halimi: A new species from Malaya and Peninsular Thailand. Biotopica 5(2):
Family: Rutaceae
Subfamily:Aurantiodeae 33 genera
Citrinae consists of 13 genera 1) Primitive 2) Near 3) True Citrus groups-genera
Primitive Citrus: Eg: Severinia bauxifolia (Chinese box-orange)
We will consider True citrus 6 genera
CITRUS
FORTUNELLA
PONCIRUS
EREMOCITRUS
CLYMENIA
MICROCITRUS
All except Poncirus are evergreen
Oil glands in all
Seeds without endosperm i

6. Fortunella Four species - Small trees and shrubs.
Flowers later than Citrus.
Freeze - hardy
Small fruit
‘Meiwa’ and ‘Marumi’ - round
‘Nagami’ ovate
4 species :F. margarita-Nagami: Cultivated in Morocco,Israel,CA and FL.
F. japonica -Marumi: Cultivated in as above.
Show picture from Page 110 from CVW book AND A SLIDE
F. polyandra: Cultivated in Malaya Peninsula
F. hindsii: Wild in China
Meiwa :hybrid between margarita & japonica
Both japonica & margarita are resistant to cold when they are dormant ...
remain dormant during warm spells in winter & early spring … escape injury from spring frosts
See page of volume I. Study how Fortunella & citrus are alike and how they are different.

7. Poncirus Two trifoliate spp. trifoliata ‘Flying Dragon’ poyandra
Deciduous
Thorny, Cold hardy, long thorns
Makes great hedges , rootstocks
Cold hardy:eg: Ornamental in North Carolina
Trifoliate leaves
A valuable rootstock : Resistant to CTV or Xyloporosis but sensitive to blight
Grown as an ornamental and hedge due to their extreme thorniness.
Troyer Citrange/ Carrizo Citrange (Poncirus is a parent of these hybrids)
Crosses with other citrus
paradisi
reticulata
limon
aurantium
Flying Dragon: A dwarf poncirus-mentioned in the root stock chapter.
Fruit Picture: Page 122 Citrus Varieties of the World book (CVWB)

8. Microcitrus Northeastern rainforest Australia Moderate-sized trees.
Leaves are unifoliate dimorphic
Microcitrus australasica
Resistant to burrowing nematode and phytophthora
Micro leaves, flowers, and fruit
6 species .. 5 are native to Australia
2 are adapted tropical rain forest…

9. Clymenia Unifoliate acuminate leaves tapering into very short petiole.
Branches are thornless.
Style shorter than other true Citrus and stigma is larger and flattened
Fruit - ovoid, thin peeled, many oil glands, many small seeds.
One species: C. polyandra
See the detailed description Vol I of Citrus Industry
While it was originally mistaken for sweet lime, it has distinct differences
1) Pulp-vesicles not on slender stalks.
2) Vesicles attached to lateral and dorsal walls.
3) Numerous stamens (50-100) with, slender filaments.
4) Blade and petiole not articulated (perhaps not compound simple leaf).

10. Eremocitrus Xerophytic native of Australia
Spreading long drooping branches
Leaves unifoliate, greyish green, thick, leatherly, and lanceolate.
Sunken stomata, freeze hardy
Ideal xeroscape plant.
Only one species in Genus E. glauca
Since it is adapted to limited water supply, it is called as a AUSTRALIAN DESERT LIME
Sunken Stomata See picture from the fig
Used in breeding program to enhance drought resistance.
Tolerant to Boran and Salt.
When dormant can tolerate low temperature.
See pages for description

11. Citrus - Subgenus Eucitrus
Vesicles - no acrid or bitter oil
C. medica (Citrons)
Uses - candied peel,
Jewish ceremony
Exocortis indicator
16 species as per Swingle, only 8 species are cultivated and 162 species as per Tanaka
Taxonomic problems:
a) Species of citrus hybridize readily
b) Citrus hybridize readily with other genera especially Fortunella & Poncirus
c) Resulting hybrids are quite different from parents and seem to be “True breeding”-- stable entities due to Nucellar Embroyony.
Based on flavonoids,and terpenoids and relative abundance of enzymes, only three important citrus species:
1) Citron (C. medica); 2) Shaddock (C. maxima) and 3) Mandarin (C.reticulata)
Sweet orange: is a hybrid between mandarin and shaddock
Grapefruit: is a hybrid between sweet orange and shaddock
Lemon: Citron and Shaddock
Lime: Citron and Shaddock or Microcitrus
Citron medica: CV. Sarcodactylis. A mutant variety, carpels are not fused and resembles Budda’s hand or Fingered Citron show the page 107 resembles human hand. Cultivated in China, Japan, and India.
Cv. Ethrog: SEE page Fruits lemon shaped…strongly ridged and very firm.
For religious rituals: the Jewish Feast of Tabernacles.

12. Citrus limon (Lemons) Commerce ‘Lisbon’ and ‘Eureka’ Dooryard
Meyer (Lemon hybrid)
Rough Lemon
Rootstock
Italian Lemon: is a hybrid of Citron, Indian Lime and Pumelo (unknown).
Origin: Punjab regions of Pakistan, and India.
Major production areas: semiarid to arid subtropical areas. Lemons are more cold sensitive than oranges, grapefruit, and mandarins, but lemons do not do well in tropical and semitropical areas.
Regions with mild winters and cool summers favor the ever-flowering tendency and more favorable for fruit-setting. This explains why lemons are produced mostly in coastal locations of southern California, Italy, Spain, and Greece.
Rind adheres tightly to the flesh and the rind is highly fragrant. Acid content is at its maximum before the fruit turns yellow. Acidity is higher in coastal than in desert lemons (5.5% versus %) and oil quality is generally higher in coastal than desert lemons.
Everbearing and repeated flowering has been exploited in Italy and Spain, where the tree growth is manipulated by cultural practices in such way that larger than normal crops are produced when fruit is scarcest. Eg: Verdelli lemon (Green Summer lemon). Page 88
Lisbon: Page 93 Common CA, Arizona, Australia, Urguay, and Argentina. More productive than Eureka. Compatible to trifoliate and citrange rootstocks. Less pronounced nipple and slightly rougher rind texture.
Eureka: Page 89-- CA, Australia, S.Africa, and Argentina’s production. Less vigrous, fewer thorns. Shorter life span. Page 89.
Meyor Lemon: ornamentale, hybrid betn. Lemon and Sweet Orange.
Rough Lemon: Rootstock in dessert areas of CA.
Ponderosa Lemon: Hybrid betn. Lemon and Citron. Dooryard ornamental in CA and FL.

13. Lemon Hybrids Lemonage (lemon x sweet orange) Lemonime (lemon x lime)
Lemandrin (lemon x mandarin)
Eremolemon (Eremocitrus x lemon) - Australian Desert Lemon

14. Citrus aurantifolia (Limes)
‘Key’ or ‘Mexican’ limes
‘Tahiti’ or ‘Persian’ limes some are triploids and seedless
C. macrophylla (lime-like fruit)
Rootstock in California
Lemonimes (lime x lemon)
Limequats (lime x kumquat)
1) Acid Limes ( C. aurantifolia): West Indian Lime, Mexican and Key Lime. Small and seedy, Grown only under extremely hot climate free from frost
Mexico, Brazil, Egypt, and India but not known Europe.
West Indian Lime- Page 99 harvested when green.
Persian Lime: C. latifolia. Seedless Page 98. Introduced into USA through SanFrancisco from Tahiti in1850 and Not grown inTahiti or Persia (Iran).
In Florida, Tahiti Lime is propagated as as marcots or air layers and this lime is grown in Dade County, where freezes are rarely experienced.
Seedlings used to produce trees ----because of high degree of polyembroyony.
Acid 7.7 % and sugar 0.3 %.
Sweet Lime: C. limettiodes : See page DEVOID OF ACIDITY ----SWEET LIME. Indian Sweet lime.
ACIDITY LESS THAN 0.1 %. Produced commercially in Portugal, India, Arabic countries, and Latin America.

15. (Citrus latifolia Tanaka)
Tahiti Lime
Persian Lime
Bearss Lime
(Citrus latifolia Tanaka)
Not grown either in Tahiti or Persian (Iran)
Seedless and marketed when still dark green

16. C. aurantium - Sour Orange
‘Seville’ in Southern Europe
Orange marmalade
‘Bouquet’ & ‘Bergamot’
- Italy
Essential oil
Many forms like ‘Bittersweet’
Rootstock - High quality fruit.
Common bitter orange widely used as a rootstock and grown in Spain.
Show the Seville sour orange fruit from page 115.
Show Citrus bergamia species plant from slide group and fruit from page 116 and explain for its disticively perfumed rind oil.
Bergamot oil is used in tea and perfume.
Most widely used rootstock in the world. However, susceptibility of sweet orange on sour orange to CTV has greatly decreased its use for new plantings in Australia, Argentina, Brazil, and California, Spain, S.Africa, and FL.
Most tolerant to Salt, and performs well on Calcarious soils but does not yield well on sand y soil.
LRGV common rootstock.
1. Swingle would include Tanaka’s C. taiwanica in this species. It was originally not susceptible to tristeza, however, recent evidence suggests that it may be susceptible to some strains in California.
2. C.aurantium has been hybridzied with trifoliate orange to from Citradias.
The USDA has a citradia that is reportedly edible and extremely cold hardy.

18. Sweet orange (Citrus sinensis) There are four classes:
Common round orange
Navels
Pigmented oranges
Acidless or sugar oranges

19. C. sinensis - Sweet Orange
Round oranges
‘Valencia’ -Worlds most imp.
‘Parson Brown’, ‘Hamlin’, ‘Pineapple’ - US
‘Shamouti’ - Israel
‘Cadenera’ - Spain
‘Pera’ - Brazil
Sweet orange are composed of four groups:
1. Normal fruits- Hamlin, Pera, and Valencia
2. Abnormal fruits or Navel fruit- “Washington Navel”
3. Pigmented oranges- Sanguinello, Maltaise, Torocco.
4. Acidless or Sugar orange: Succari, Mosambi
Sweet orange… most extensively grown of the citrus species.
Origin in China: Sinensis means CITRUS OF CHINA.
Show the slide- Valencia- from page 23 and explain effect of subtropical and tropical (Cuba). Production in Argentina, Australia, CA, FL, Morocco, S. Africa, Uruguay , Brazil, and Israel.. Valencia orange fruit store well on the tree.. So both crops may be present throughout simmer months in young grooves.
Problems with Valencia: 1) Has tight peel.. Messy to peel. FL- Juice and CA- Fresh market. 2) Alternate bearing 3) Rind Crease: “ ON” year in coastal areas. .. Can be reduced by KNO3 foliar spray at 40 lbs/100gal and gal/acre. EXPENSIVE 4) Regreening: Regreening starts at stem end. A) amplified by warm weather b) fruit stored on tree c) mainly a cosmetic problem d) degreening with ethylene.. Mention problems. 5) small sizes during “ ON” yeas” 6) granulation: Juice vesicles harden & become nearly colorless. Vesicles loose sugar, loose acid, become gelatenous.
HAMLIN: Chance seedling in FL. Slide 1: Early maturing due low acid, size is good in hot and humid semitropics, FL. Size is too small in arid and subtropics. Major variety in FL but mixed with other juice because of poor flavor and color. PARSON BROWN: Slide 2. Seediness and fruit size problem. PINEAPPLE: SLIDE 3. Mid season variety in FL seed.ft. High juice content,good color and flavor. In FL: Harvest starts with Hamlin, then Pineapple and Valencia.
Shamouti: Page 21- best quality in Coastal belt of Israel. Develop delayed bitterness like navels.
Cadenera: No picture: Seedless, Spain, Morroco, Algeria.
Pera: page 20: Frt. Smaller than Valencia. Good for juice industry. Uneven flowering

20. C. sinensis - Navel Oranges
Secondary fruit - easy ID
Fresh fruit - Gift packs
Lower acid thus sweeter taste
Limonin in juice can be removed
Environmental stresses
Best quality in cooler climates
Second most important in the world. Secondary fruit shown in page 11 picture.
Needs high summer to develop good fruit quality. Needs diurnal temp fluctuations for good color. California is a ideal place to grow. Poor processing fruit:
1) Relatively low juice content
2) Bitter compound (LIMONIN).
3) Taste threshold is 4-5 ppm. Frshly extracted juice is not bitter.. Becomes bitter within 24 hrs. Explain later when covering phytochemicals.
Late season navels are suitable for juice market. SEEDLESS:
a) functional pollen lacking.
b) Viable ovules are rare.
Fruit with crisp texture. Peels easily.
Segments separate easily.
An excellent dessert fruit.
Susceptible to enviornmental stresses.
US, Spain, Australia, Morocco, Algeria

21. Sweet orange, Citrus sinensis (Round orange) ‘Valencia’

22. Valencia Orange, Israel

23. Valencia chimera green and yellow

24. Round oranges (for juice)
Fortune
Fremont

25. California Navel Oranges
‘Washington’ most widely grown
Old line replaced by nucellars
‘Atwood’, ‘Fisher’, ‘Newhall’ are earliest navels
‘Lane Late’ - late maturing, fruit hold well on tree.
Show picture from page 15.
Washington Navel orange is the best known navel orange.
Navel originated by mutation in Bahia, Brazil and arrived in CA by two ways.
1) English orangeries via Australia
2) Received by USDA in 1870, propagated in Wash DC. (glasshouse)… sent to CA and FL 3 years later.
Trees planted in Riverside by L.C. Tibbets resulted in Washington. He planted 3 door yard trees. One died.
In 1903 one of the two surviving trees was moved to Mission Inn.. It died. The other was moved from Tibbets place to it s present location (Magnolia and Arlington).
Skaggs Bonaza: A patented variety. Early maturing variety. Problem: Galls on trunk.. Reduced vigor is presumed to be assoiciated with galls.
Lane Late: Low limoni content. Budsport of Washington navel near the property of Lane Curlwaa, Australia. Australia possible to leave fruit on tree until April but in CA regreens late spring and Summer.

26. Navel orange ‘Washington Navel’

27. Spanish Navels
‘Navelina’ sport of ‘Washington’ at Riverside, CA
Early season, smaller tree, and holds well on tree.
‘Navelate’ sort of ‘Washington’ late maturing - vigorous tree.
Navelina: Origin in California.
Early maturing than Washington navel.
Navelate: Spain. Concealed navel.
Erratic performer even in Spain.

28. Texas Navels ‘Washington’ - most widely planted navel in world
‘Marrs’ - limb sport of ‘Washington’ lacks distinct secondary fruit.
Early maturing, low acid.
Lower in limonin.
‘Marrs’- limb sport on a navel tree on O.E. Marrs’ property at Donna, TX 1927.
Reaches legal maturity early because of low acidity. Flavor improves, if left on the tree until November.

29. Florida Navels
‘Summerfield’ early maturing - adapted to humid climate.
Nucellar selection - F most widely used in new plantings.

30. Brazilian Navels ‘Baianinha’ - ‘Bahia’ limb sport
Less vigorous and smaller secondary fruit, thus
Less prone to fruit drop
Adapted to hot, arid climate

31. Australian Navels ‘Leng’ major navel orange ‘Washington’ sport - 1934
Small size, thinner peel.
‘Lane Late’ - late season but subject to regreening and granulation.

32. South African Navels South Africa
‘Palmer’ nucellar seedling of ‘Washington’ s
Vigorous, productive, hold well on tree
‘Robyn’ - cooler location

33. Venezuelan Navels ‘Cara Cara’
Red flesh even in lowland tropics (uncharacteristic of blood oranges)
Show slide of Red Navel

34. Pigmented Oranges
Grown in Mediterranean climates with hot days and cool nights.
Anthocyanin pigment rather than
lycopene as in grapefruit
carotenoid as in oranges
‘Tarocco’, ‘Sanguinello’, ‘Maltaise
Better color: Diurnal fluctations of temp- Low night temp are needed. Red color does not develop in Tropics.
2. Cold storage intensifies color.
3. Color best on partially shaded fruit.
Show pictures of Torocco (Page-29) , Sanguinelli (page 28), and Maltaise (page 26).
Maltaise orange- Queen of oranges
Torocco- Italys’ finest quality orange variety.

35. Acidless or Sugar oranges
Low acid levels
Therapeutic properties
Succari-Egypt
Mosambi-East African/Portuguese
Succari--- Show page 31 picture

36. C. sinensis Hybrids Citranges (sweet x trifoliate)
Citrangors (sweet x citrange)
Citrangequats (citrange x kumquat)
Citrangeremos (citrange x Euremocitrus)

37. Citrus reticulata Highly prized for easy peeling (zipper skin).
Satsuma group
Primarily grown in Japan
Important in Louisiana and for dooryard in Gulf Coast
Tangerine group
Commercial in Fla. - ‘Dancy’ and ‘Clementine’ -deep orange
We will use mandarin to refer to tangerines, mandarines, mandarin oranges, tangelos, tangors, and other hybrids of tangerine with other citrus.
Tangerine…commonly used in market place to refer to the more orange colored members of this group.
Hodgson says 4 species
Tanaka says 26 species
Swingle says species reticulata.
Satsuma mandrin- C. unshiu
Show the picture of Satsuma from Page 35
King mandrin- C. nobilis
Mediterrannean mandarin- C. deliciosa
Coommon mandarin- C. reticulata
Show Clementine from page 41: Famous in Morocco, Spain.
Show the slide next with Dancy tangerine

38. Tangerines are small erect trees that. fruit at the end of branches
Tangerines are small erect trees that fruit at the end of branches. The branches tend to be erect. The skin is loose and is hard to pick without damage but is the highest priced fruit. In Florida 10% of tangerines can be legally added to frozen orange concentrated for color.

39. Tangerines along roadside in Japan

40. Dancy Tangerine Production problems alternate bearing
Susceptible to Alternaria

41. Swingle and Tanaka Differ
Satsuma
C. reticulata - C. unshiu
‘Dancy’
C. reticulata - C. tangerina
‘Cleopatra’
C. reticulata - C. reshni

42. More differences ‘King’ tangor? C. noblis ‘Temple’ tangor? C. temple
‘Calamondin’
(C. reticulata x C. ichangensis)
C. madurensis

43. Breeder’s Delight
‘Clementine’ and ‘Temple’ produce only monoembryonic seeds.
No nucellars.

44. Temple Orange Named after W.C. Temple from FL.
Hybrid of mandarin and orange

45. Murcott or Honey Tangerine
It is hybrid of unknown parentage
Fruits are borne terminally so they are vulnerable to wind.

46. Ponkan (Chinese Honey orange, Nagpur Santra)
Widely grown mandarin in the world
Alternate bearing

47. Tangerine x Grapefruit
‘Orlando’ tangelo
‘Minneola’ tangelo
‘Page’ orange
‘Robinson’ tangerine
‘Nova’ tangelo
‘Ugli’ tangelo

48. Tangelos Commercial - ‘Orlando’ and ‘Minneola’ ‘ Dancy’ x ‘Duncan’
Vigorous
Freeze hardy
Weakly parthenocarpic

49. Tangelos Continued Fruit set by either Cross pollination GA3
Which would be best for fresh market?

50. Orlando tangelo Duncan grapefruit x Dancy tangerine leaves cup-shaped
seedy

51. Orlando Most cold hardy of all comm. citrus except satsuma.
Oblate to subglobose
Seedless to seeds
+ correlation between fruit size and seed number.
Harvest between Dec - Jan NH

52. Orlando Continued Pollinators ‘Temple’ ‘Robinson’
More Nitrogen required than for round oranges because tree is more vigorous.

53. Minneola Tangelo Duncan x Dancy Cold-resistant
Distinct flavor being rich (from Dancy) and tart from Duncan).

54. Minneola Vigorous tree Tree - large and spreading
Leaves - large, pointed laminae
Petioles - moderate size
Fruit - large obovate with neck
Color - Deep reddish orange.

55. Minneola Continued Juice flavor - excellent
Peel moderately adherent - finely pebbled
Seed
Matures - Jan to March - NH
July to August - SH

56. Minneola Continued Pollinators are ‘Temple’ and ‘Robinson’
‘Orlando’ will not pollinate ‘Minneola’
Large solid blocks set seedless fruits with GA3

57. Nova (Clemenvilla, Suntina)
Fina Clementine x Orlando tangelo
Seedless when grown apart from pollinating varieties
Spain and Israel

58. Page Minneola x Clementine Sensitive to Bromacil
Usually referred to as ‘orange’