Citrus Fruit Cultivation in India – Production Area, Climate, Harvesting and Fruit Handling! Citrus comprises many species of economic importance. In India few species are commercially cultivated, which include grape fruit, lemons, limes, sweet oranges, and mandarins. Kinnow a hybrid between King mandarin x Willow leaf orange produced by H.B. Frost in 1915 and released in 1935 was introduced by Dr. J.C. Bakhshi at Abohar research station during 1954. This is being cultivated throughout North India and even in other citrus growing states. The cultivation of citrus fruits has taken a boost due to the entrance of some private companies, who are providing their own plant material. It is a matter of time that will prove whether the new orange cultivars are a failure or success. If, this venture is successful then monoculture of Kinnow in this region shall be restricted. Efforts are also on to improve the technical knowhow for Blood Red and Nagpuri mandarin. Grape fruits are also being planted to meet the requirement of citrus fruits for sugar patients. Origin: Citrus originated in South East Asia. North East region of India is the home of some citrus species e.g. mandarins. Nagpur Sangtra is grown on a large scale in the Vidharbha region of central India. Similarly in Assam, Brahmaputra Valley and Dibrugarh district are famous for mandarin production. Khasi mandarin is an important cultivar of Nilgiri hills. After manda­rins, limes and lemons are also cultivated throughout India. In India citrus is cultivated over an area of near about 923.2 thousand hectares with an estimated production of 8607.7 thousand metric tonnes. In Punjab citrus occupies 39.198 hectares with annual production of 734699 MT. Kinnow occupies 54.9% of the area under citrus. Botany: Genus citrus belongs to family Rutaceae and sub-family Aurantioedae. While classifying citrus. Swingle has been considered to be a lumper (with 16 species only) and his student Tanaka a spliter (157 species). Hodgson (1967) classified citrus in to 36 species of commercial importance. This classification is the most accepted one. Hybridization in citrus has led to produce a large number of inter-generic and inter-specific hybrids. Most of them are used as potential rootstocks. For example, citranges (trifoliate orange X sweet orange), citrumelo (trifoliate orange X grape fruit), citrandarin (trifoliate orange X mandarin) and limequats (kumquat X West Indian lime). One of the parents trifoliate orange was choosen for its cold hardiness and dwarfing character as a rootstock.

1. Subject – Breeding of fruit crops
Present By : Amrinder Singh
Assistant Professor
Desh Bhagat University

2.  India rank sixth in the production of citrus fruit in the world .
 Other major citrus producing countries are Spain , USA ,
Israel, Morocco, South Africa, Japan , Brazil , Turkey , Cuba.
It occupies third position after mango and banana in the
production of fruits in India.
 Citrus fruits originated in the tropical and subtropical regions
of South East Asia , particularly India and China . North East
India is the native place of juice many citrus species .
 It is of particular interest because of its high content of vitamin
C and refreshing juice .

3.  Citrus plants are members of the Rutaceae family , within which seven
subfamilies have been recognised .
 The orange subfamily “ Aurantioideae” is of main concern because it includes
citrus and it’s nearer relatives represented by 28 genera in the tribe “Citreae” .
 Six of these genera ( Eremocitrus , Poncirus , Clymenia, Fortunella,
Microcuries and Citrus ) comprise the true citrus fruits , evergreen trees with
highly specialised pulp vesicles in the fruit .
 The three most closely related genera are : Citrus , Fortunella and Poncirus.
 Poncirus , a monotype genus , occurs naturally in central and North China ,
sheds it’s leaves in winter and is highly resistant to cold .
 Fortunella is evergreen but owes it’s hardiness to a prolonged winter dormancy .
 Eremocitrus is highly drought resistant .
 The genus Citrus consists of two subgenera : Papeda and Eucitrus.

4. 1. Sweet orange ( C.sinensis )
 Common or round orange
2 . Mandarins
 Common mandarin
( Citrus reticulata )
3 . Grapefruit ( Citrus paradise )
 White fleshed
 Red fleshed
Hamlin , Valencia , Pera ,Delta,
mosambi , pineapple ,Frost
Clementine , fina , ponkan , pongan
, Nagpur , Darjiling , Coorg , khasi ,
Beauty , fortune .
Duncan , Marsh , Walters
Star ruby , Foster , Hudson ,
Thompson Ruby Red .
Citrus group Cultivars

5. 4. Lemons ( C. limon)
5. Pummelo ( C. gradis)
6. Kumquat ( Fortunella spp. )
 Hamlin , Valencia, Netal , Pera ,
Delta, Pineapple, Mosambi,
Frost.
 Chander , Deleema, Kopjar,
Galgal , Mato, Goliath.
 Nagami, Meiwa, Marumi ,
Calamondin .

6. Sweet oranges Mandarins
Grapefruit – white fleshed Grapefruit - red fleshed

7. Lemons

8. Kumquat

11.  Time of flowering in citrus trees is greatly influenced by environmental factors ,
particularly temperature and soil moisture .
 When grown in a Mediterranean or a subtropical climate, the most species have
only one annual period of bloom .
 The time of flower bud induction appears to be initiated by November and may
continue upto early January depending upon climatic conditions .
 In lime and lemons, flowering generally occurs in two major peaks seasonally,
but may also occur continuously at reduced intensity producing crops per year.
 Temperature below 25° C for several weeks appear to be required for induction
of flower buds in significant quantities.
 The flower in Citrus are hermaphrodite borne singly or in small groups in the
axils on the young twigs. They have a variable number of white petals , most
often five and commonly five small, greenish coloured sepals .

14. 1. Citrus fruits are usually grown by budding scions on rootstock. The rootstock
greatly influence the performance of a scion by modifying it’s tree morphology
and imparting resistance to biotic or abiotic stresses. Thus the breeding
programmes have been carried on for both scions and rootstock .
2. Objectives for fruit – quality breeding may vary considerably from one species
to another species . There may be a need to enhance acidity in lemon . Fruit size
has been a limiting characters . Hybrids of good size and flavour have been
obtained but high seed number is a persistent problem.
3. The objectives for breeding a suitable rootstock should include better stock-
scion compatibility , reduction of tree size without affecting yield or scion health
and resistance to pests and diseases . A rootstock with the tolerance of
Phytophthora possessed by sour orange without its susceptibility to the tristiza
virus is needed.

15. Hybridization in citrus has been under practice for over 70 years
with objectives to breed superior cultivars for specific characters
like pests and disease resistance , cold hardiness , better fruit
quality , dearness , thornlessness or salt tolerance . In general ,
much of the hybridization in citrus has been interspecific rather
than intraspecific . This still continues to be the pattern although
the major breeding programmes are now utilizing more second
and third generation hybrids from original interspecific crosses (
Soost , 1987) .

16. • Spontaneous mutation , as evidenced by sudden change
in heritable character , occurs frequently in citrus .
• Mutations are often observed as limb sport or sectors on
fruits ; they are also detected occasionally in nuceller
seedlings or their budded progeny .
• The ‘Washington Navel’ orange ‘Marsh’ and
‘Thompson’ grapefruits are few examples of valuable
spontaneous mutations .
• There are also man – made mutations , , buddwoods
and seeds are treated for short periods with gamma
irradiation to induce mutation without killing the cells .
• The resulting seeds or buds are planted out or
propagated by tissue culture techniques.

17.  Polyploidy involves three or more sets of chromosomes and may occur naturally
or by induction . Nearly all plants and animals probably have some polyploid
tissues .
 Diploidy is the general rule in citrus and it’s related genera but occurrence of
polyploidy has been reported in many cultivars .
 The Hongkong wild kumquat , Fortunella hindsii , swing may have been the first
reported tetraploid .
 Hybrid tetraploid seedlings seldom occur from crossing diploids , but several
spontaneous tetraploids in Citrus and Poncirus have occurred as nuceller
seedlings. Tetraploids grow more slowly and are more compact and generally
less fruitful than comparable diploids . Leaves are broader , thicker and darker.
Fruits usually have thicker rinds , larger oil glands and less juice than diploids .
 Triploids have favourable characteristics and Yield well , but they are sterile .

18.  Biotic stress : Evolving pests and
diseases resistant varieties there by
reducing cost of cultivation ,
environmental pollution and
saving beneficial insects .
 Abiotic stress : It is location
specific problem . Soil factors and
edaphic factors sometimes poses
severe problems . Breeding
resistant varieties is the easy way
to combat abiotic stress.

19.  The RFLP ( Restriction fragment length polymorphism ) method has
also been used to develop maps of the citrus genome that may be
useful in locating genes with a specific function (Gmitter et al. 1996) .
Marker genes are identified on specific chromosomes , some of which
are tightly linked to other genes responsible for factors like disease
resistance or freeze hardiness .
 The RAPD’s ( Random amplified polymorphic DNA) analysis has
been successfully carried out to evaluate polymorphism and genetic
variation between mandarin or lemon genotypes and identification of
somatic hybrids in citrus ( Shi et al. 1998) .