citrus rootstocks
TRANSCRIPT
Of CITRUS ROOTSTOCKS
Description Identification Multiplication
WAQAS AHMEDM. Sc (Hons.) Agriculture
(Horticulture)
Origin and History
Origin and History
Citrus is considered to be native of Southeast Asia, especially
eastern India.
Phylogenic relationships extends through East Indies,
Australia, central China, Japan and even Africa.
Many present day citrus cultivars have been cultivated
since ancient times and their wild progenitors are not definitely
known.
Origin and History
Citrus is grown in tropical and subtropical southeast regions of the
world, in a belt of approximately;
35° N and S of the equator.
Origin and History
There is a great diversity in citrus;
size
shape
fruit colour
juice contents
The most well known examples are the orange, the lemon, the
grapefruit, the lime and tangerines.
History of improvement
History of improvement
First organized programme was started by USDA in Florida in 1893
by W.T. Swingle and H.J. Webber.
Disease management
(This programme was destroyed due to severe freeze in winter in
1894-95)
History of improvement
In 1908, USDA group produced large number of hybrids from
many combinations of cultivars and species.
‘Troyer’, among these, is an important rootstock
In University of California citrus breeding started in 1914, by H. B.
Frost.
University of Florida started two citrus breeding programmes in
1924 and 1956.
Classification of Citrus
Classification of Citrus
Plantae Kingdom
Magnoliophyta Division
Magnoliopsida Class
Rosidae Sub-class
Sapindales Order
Rutaceae Family
Aurantioideae Sub-family
Citreae Tribe
Classification of Citrus
W. T. Swingle classified sub family Aurantioideae into a very
comprehensive treatment.
Citrus (16 species)
Fortunella (4 specie)
Poncirus (1 specie)
Eremocitrus
Microcitrus
Citrus, Fortunella and Poncirus can be crossed with one another,
and various proven hybrids exist.
Classification of Citrus
Citrus aurantifolia Key Lime
Citrus maxima Pomelo
Citrus medica Citron
Citrus reticulata Mandrin
Microcitrus
Classification of Citrus
Some hybrids are;
Grapefruit X Tangerine Tangelo
Orange X Tangerine Tangor
Grapefruit X Orange Orangelo
Sweet orange
X Poncirus Citrange
Sour orange
X Poncirus Citradia
Kumquat X Citrange Citrangequat
Botany
Citrus Tree
Shrub or small tree
Type
5-15 m Height
Ever green Growth habit
On twigs attachment
Spines
Alternate Leaves arrangement
Shiny, leathery, dotted with oil glands
Leaf characters Citrus tree facts and info.
www.citrustreesnola.com
Citrus Flower
Solitary Type
2-4 cm Diameter
6-14 carpel Ovary
4 X of petals Stamens
4-8 (Thick, Linear) Petalscitrus sinensis. www theflowerexpert.com
Flowers are very strongly scented. The vegetative apical
meristem transforms into a terminal flower bud. Axillary flower
bud develops later than the terminal bud.
Citrus Fruit
Citrus. www.botany.com
A leathery rind surrounding segments or "liths" filled with pulp
vesicles.
Hesperidium berry
Type
Globose to elongated
Shape
Length= 4-30 cmDiameter= 4-20 cm
Size
Technical terms
Usual terms
Juice Sac
Mesocarp
Segment
Zest
Pulp
Rind
Exocarp
Citrus Rootstocks
Citrus rootstocks
The plant or plant part (One of the components of budding or
grating) which provides root system after successful union of bud
or graft with it.
Citrus plants grown in the "normal" way from seedlings have
several problems. Due to the complicated and in part fascinating
reproductive life of citrus plants;
A tree grown from a zygotic seed seldom grows true to
type.
Seedlings grown tree take up to 7-12 years before they
grow a trunk and a
root system strong enough to bear fruit.
Citrus rootstocks
For getting superior true to type plants and reducing the bearing
period, asexual means of reproduction are implemented.
Citrus rootstocks
Different qualities can determine the choice of rootstock;
Tree vigor
Rooting depth
Time to reach fruit maturity
Tolerance to cold and water logging
Resistance to nematodes, foot rot (phytophthora), citrus
blight
Susceptibility to citrus tristezza, exocortis and xyloporosis
viruses
Commercially used Citrus rootstocks in Pakistan
Citrus rootstocks used in Pakistan
However, there are a range of different
rootstocks growing at research stations and
germplasm units but they have not been
commercialized.
Punjab Kinnow mandarins
Rough Lemon
NWFP Orange Sour Orange
Rough Lemon
Rough lemon
Citrus jambhiri
Origin:
Rough lemon originated in the Himalayan
foothills in India.
Rough lemon
Very vigorous Vigor
Spreading Growth habit
Dense Density of branches
Rough lemon. Sweating Canning Growing. 2009
www. chilechews.blogspot.com
Rough lemon
Simple Leaf division
Light Green Leaf colour intensity
Not winged Petiole
Rough lemon.
www.bugsforbugs.com.au
Rough lemon
Advantages:
Tolerant to tristeza
Drought tolerant
Moderate tolerance to salinity
Disadvantage:
Less cold hardy
Intolerant to blight
Susceptible to phytophthora foot rot and burrowing
nematodes
Rough lemon
Uses:
Fully compatible with compatibility with oranges, grapefruit,
tangelos
and most mandarin varieties.
Sour orange
Sour orange
Citrus aurantium
Origin:
The sour orange is native to southeastern
Asia. Arabs are thought to have carried it
to Arabia in the 9th Century.
Sour orange
Vigorous Vigor
Spreading Growth habit
Dense Density of branches
Alexandris, G. Sour orange tree.
www.fotolia.com
Versatile sour orange. www.fincalasbrisas.org
Sour orange
Simple Leaf division
Dark Leaf colour intensity
Winged Petiole
Sour orange tree.
www.bayflora.com
Sour orange
Advantages:
Tolerant to cold
Drought tolerant
Resistance against gummosis
Tolerate salinity and alkalinity
Disadvantage:
Intolerant to tristeza
Susceptible to nematodes
Sour orange
Uses:
Grapefruit and orange yields on sour orange are moderate,
with average fruit size and good quality.
Other rootstocks
Sweet orange
Sweet orange
Citrus sinensis
Origin:
Sweet orange are native to southeastern
Asia, northeastern India or, more likely,
southern China and Indo-China.
Sweet orange
Medium Vigor
Spheroid Tree shape
Spreading Growth habit
Citrus sinensis. Plante E Animali Italiani.
www.digilander.libero.it
Sweet orange
Simple Leaf division
Elliptical Leaf shape
Narrowly winged Petiole
Citrus sinensis-Sweet orange.
www.plantoftheweek.org
Sweet orange
Advantages:
Quite hardy
Resistance against cold
Tolerant to quick decline
Disadvantage:
Sensitive to soil salinity
Susceptible to gummosis
Sweet orange
Uses:
Sweet orange is a good rootstock for all the citrus cultivars,
producing large, vigorous trees. Yields and fruit quality
produced on sweet orange stock are good and unions are
compatible.
Kharna Khatta
Kharna khatta
Citrus aurantium var. khatta
Origin:
Karna is an old Indian fruit of unknown
origin, most probably native to Tropical
Asia, Indo-China.
Almost certainly a natural hybrid. While the
tree and fruit are distinctive, they exhibit
characters of both rough lemon and sour
or bitter orange.
Kharna khatta
Medium Vigor
Spreading Growth habit
Upright Tree habit
Spheroid Tree shape
Kharna sour orange hybrid.
www.citrusvariety.ucr.edu
Kherna khatta
Simple Leaf division
Dark Leaf colour intensity
Winged Petiole
Jaskani, M. J. et al. 2006. Pak. J. Bot.,
38(2): 311-317
Kherna khatta
Advantages:
Tolerant to cold
Drought tolerant
Tolerate salinity and alkalinity
Disadvantage:
Susceptible to tristeza
Susceptible to gummosis
Kherna khatta
Uses:
Grapefruit and mandarins can be grown successfully on Kharna
khatta.
Rangpur lime
Rangpur lime
Citrus limonia
Origin:
Rangpur lime has Indian origin. It is hybrid
involving either the rough lemon or sour
orange in the parentage.
Rangpur lime
High Vigor
Spheroid Tree shape
Spreading Growth habit
Baishaishu Rangpur lime.
www.citrusvariety.ucr.edu
Rangpur lime
Simple Leaf division
Elliptic Leaf shape
Obovate Petiole
Rangpur. Citrus limonia
www.steffenreichel.homepage.t-online.de
Rangpur lime
Advantages:
Drought tolerant
Tolerate salinity
Highly resistant to tristeza
Disadvantage:
Sensitive to cold
Susceptible to phytophthora
Susceptible to burrowing nematodes
Rangpur lime
Uses:
It makes a good union with number of citrus spp. Like sweet
orange, mandarins and pummelo.
Trifoliate orange
Trifoliate orange
Poncirus trifoliata or Citrus trifoliata
Origin:
Trifoliate oranges are native to central or
northern China. It is widely cultivated in
temperate regions.
Trifoliate orange
Medium Vigor
Ellipsoid Tree shape
Spreading Growth habit
Trifoliate orange. www. users.kymp.net
Trifoliate orange
Trifoliate Leaf division
Ovate Leaf shape
Obovate Petiole
Poncirus trifoliata.
www.plantsystematics.org
Trifoliate orange
Advantages:
Resistant to tristeza
Tolerant to cold and water logging
Resistant to phytophthora and nematodes
Disadvantage:
Sensitive to drought
Intolerant to salinity
Slow growing rootstock
Trifoliate orange
Uses:
It is used in high density planting as it is a dwarf rootstock. It is
a good rootstock for sweet oranges, tangerines and grape fruit.
Cleopatra mandarin
Cleopatra mandarin
Citrus reshni
Origin:
Cleopatra mandarin are native to tropical
Asia, Indian subcontinent.
Cleopatra mandarin
Medium Vigor
Spheroid Tree shape
Spreading Growth habit
Cleopatra mandarin. www.users.kymp.net
Cleopatra mandarin
Simple Leaf division
Elliptic Leaf shape
Obovate Petiole
Citrus reshni. www.flora-toskana.de
Cleopatra mandarin
Advantages:
Cold hardy
Tolerate salinity and alkalinity
Resistant to tristeza, gummosis and quick decline.
Disadvantage:
Sensitive to nematodes
Sensitive to water logging
Susceptible to phytophthora
Cleopatra mandarin
Uses:
Blood red and Valencia oranges perform well when budded on
Cleopatra mandarin.
Carrizo citrange
Carrizo citrange
Hybrid of;
Washington navel orange X Poncirus
trifoliata
Purpose was to combine cold hardiness of
trifoliate orange with good traits of sweet
orange.
Origin:
The original crosses were made in the early
1900s by the United States Department
of Agriculture with the intention of
producing cold tolerant scion cultivars.
Carrizo citrange
Moderate Vigor
Ellipsoid Tree shape
Spreading Growth habit
Dense Density of branches
Oklahoma Cold Hardy Citrus Hybrid Project.
www.okcitrus.com
Carrizo citrange
Simple Leaf division
Dark Leaf colour intensity
Winged Petiole
About1418 citrus.
www.citrus.forumup.org
Carrizo citrange
Advantages:
Cold tolerant
Tolerant to tristeza
Tolerant to Phytophthora and nematode
Disadvantage:
Adversely affected by high pH
Sensitive to soil salinity and water logging
Carrizo citrange
Uses:
Fully compatible with navel and Valencia orange varieties.
Troyer citrange
Troyer citrange
Hybrid of;
Washington navel orange X Poncirus
trifoliata
Origin:
It was originated as a hybrid of the
Washington navel orange crossed with
trifoliate orange pollen that was made at
Riverside, California in 1909. In 1934,
Swingle named it for A. M. Troyer, on
whose place at Fairhope, Alabama, it first
fruited.
Troyer citrange
Moderate Vigor
Spreading Growth habit
Moderate Density of branches
Citrange, 'Troyer‘. www.woodlanders.net
Troyer citrange
Medium Leaf size
Trifoliate Leaf division
Dark Leaf colour intensity
Citranges.
www.homecitrusgrowers.co.u
k
Troyer citrange
Advantages:
Cold tolerant
Tolerant to tristeza
Tolerant to Phytophthora and nematode
Disadvantage:
Adversely affected by high pH
Sensitive to soil salinity and water logging
Troyer citrange
Uses:
Troyer citrange is the major rootstock used for mandarins.
Citrange-35
Citrange-35
Hybrid of;
Poncirus trifoliata X Citrus sinensis
Origin:
The cross was made by J.W. Cameron & R.C.
Baines in the Citrus Research Center,
Riverside, CA, in 1951.
Citrange-35
Medium Vigor
Spreading Growth habit
Spheroid Tree shape
Citranges‘. www.woodlanders.net
Citrange-35
Elliptic Leaf shape
Trifoliate Leaf division
Obovate Petiole shape
Citranges‘. www.woodlanders.net
Citrange-35
Advantages:
Cold tolerant
Drought tolerant
Tolerant to tristeza
Tolerant to Phytophthora and nematode
Disadvantage:
Sensitive to soil salinity
Adversely affected by high pH
Citrange-35
Uses:
Citrange 35 is used as rootstock for navel oranges, grapefruit
and valencia oranges.
Breeding in Citrus
Breeding in Citrus
W. T. Swingle classified sub family Aurantioideae into a very
comprehensive treatment.
Citrus (16 species)
Fortunella (4 specie)
Poncirus (1 specie)
Eremocitrus
Microcitrus
Citrus, Fortunella and Poncirus can be crossed with one another,
and various proven hybrids exist.