CITRUS
Citrus
◼ Family Rutaceae
◼ Botanically Citrus is a name of genus but in horticulture, following
three genera
◼ Citrus
◼ Poncirus and
◼ Fortunella
◼ These 3 genera are distinguished by leaf and ovary characteristics
Citrus Poncirus
Fortunella
Fortunella
Poncirus
Citrus
◼ Citrus unifoliate & evergreen
ovary 8 or more cells
◼ Fortunella unifoliate & evergreen
Ovary 3-6 celled
◼ Poncirus deciduous and trifoliate
Citrus
◼ Evergreen trees and shrubs
◼ Spiny with thick leathery leaves
◼ Winged to wingless petioles
◼ Flowers white, pinkish from outside in lemon and
Citron
◼ Pentamerous
◼ Axillary or terminal cymes
◼ Scented
◼ Ovary superior with 8-15 carples with few to
several ovules
Citrus
◼ Fruit
◼ Thick leathery rind
◼ Special berry called hesperidium
◼ Globose, sub-globose, ellyptical
◼ Filled with juice sacs and vesicles
◼ Few- many white or light green seeds
◼ polyembryonic
Commercial Citrus Sp.
◼ Mandarins C. reticulata Blanco
◼ S. Oranges C. sinensis (L) Osbeck
◼ Grapefruit C. paradisi Macf.
(Pomelo)
◼ Chakotra C. grandis (L) Osbeck
pummelo
◼ Sweet lime C. limettoides Tan.
◼ Kaghzi Lime C. aurantifolia Swing.
◼ Lemon C. limon (L)
◼ Citron C. medica (L)
◼ Sour Orange C. aurantium (L)
◼ Rough Lemon C. jambheri Lush
Distribution And Importance
◼ Tropical and sub tropical
climate.
◼ In Pakistan citrus grown
in 196 thousand hectare.
◼ Production is 2.3 million
tones.
◼ Only Punjab produces
95% of the crop.
(Pakistan Bureau STAT, 2022)
Area ("000" Hectares)
Production "000" tons
Punjab
Sindh Punjab Sindh KPk Balochistan
Total Area=181.7
(“000” Hectares) Total Production=
2468.7 (“000” tons)
Citrus Area and Production in Pakistan
Citrus Status Among All Fruits In Pakistan
Area Production
Commercial Varieties
◼ Mandarins: Kinnow and Feutrell’s early
◼ Sweet Oranges: Blood Red, Pineapple and
Musambi, Succari.
◼ Grapefruit: Marsh seedless, Foster and Shamber.
◼ Others: Kaghzi Lime, Eureka Lemon and Sweet
Lime.
Kinnow Mandarin
Sweet Orange cv. Musambi
Grapefruit cv. Shamber
Kagzi Lime
(Desi Lime)
Sweet Lime
Rough Lemon
Rootstock
Fortunella
Kumquat
Poncirus trifoliata
(Rootstock)
Successful Hybrid Sp.
◼ Citrange Pon. X Sw. Orange
◼ Citrangequats Citrange X Fortunella
◼ Tangelos Mandarin X Grapefruit
◼ Limequats Lime X Fortunella
◼ Citrumellos Pon. X Grapefruit
◼ Citrandrins Pon. X mandarins
Soil
◼ Soil Requirements
◼ wide range of soil
◼ sandy loam or loamy soil are preferable
◼ do not grow well in heavy, clayey, alkaline and
waterlogged soils.
◼ pH 5.5-8.5
◼ Soil req. depend on type of root stock used
◼ Rough lemon for dry, sandy loam soil
Climate
◼ Tropical and subtropical climate
◼ Cool regions
◼ vegetative growth is slow
◼ ripening is delay
◼ Fruit may be acidic
◼ Can not grow
◼ below13°C
◼ above 40°C.
◼ Max. temp. Tolerante 46-50°C.
Propagation
◼ Both sexual and asexual.
◼ Sexual
◼ Through seeds
◼ Fruit are taken from healthy trees by the first week
of Sept. for seed extraction
◼ Rough Lemon Rootstock in Punjab
◼ Sour Orange Rootstock in KPK
◼ Asexual
◼ Through budding (T budding at commercial scale)
Steps in Propagation of Kinnow Mandarin
Preparation of Scion wood
Preparation of Scion wood
Cultural practices
◼ Cultivation and interculture
◼ light cultivation during early years
◼ to eradicate weeds.
◼ Ploughed five to six times
◼ September ploughing perform better.
◼ Intercropping
◼ Only for early 2-3 years (Leguminous crops)
◼ helpful in adding humus,
Irrigation
◼ Frequency and amount of irrigation depend upon
◼ Soil/ Climatic conditions
◼ Method of irrigation (Flood/Drip/Sprinkler)
◼ Age of tree/ Tree spacing
◼ Fortnightly in summer (for Flood irrigation)
◼ Restricted watering during winter (monthly)
◼ Irrigation Method
◼ Basin and modified basin systems (young trees)
◼ Flood irrigation through wider ridges (old trees)
◼ Modern orchard use drip / low head sprinklers
Fertilization
◼ No general rule
Depends upon,
◼ Soil/ Climate type,
◼ Cultivar and
◼ Root stock
◼ Tree spacing
◼ FYM (50 to 100 kg/plant)
◼ Fully decomposed
◼ Apply during winter season (Dec./Jan)
◼ Inorganic Fertilizer (Per plant)
◼ 1000-1500 g N (In 2-3 splits)
◼ 500 g P
◼ 500 g P
Pruning
◼ Judicious removal
◼ Pruning is done to develop a strong tree skeleton.
◼ To increase production
◼ Pruning of lemon is essential to overcome apical
dominance.
◼ It should be done during late winter or early spring.
◼ Mandatory in High Density Orchards
Citrus
Physiological Disorders
Disease vs Physiological Disorders
◼ Alternate bearing
◼ Granulation
◼ Fruit drop
◼ Unfruitfulness
Alternate Bearing
➢ Frequent in
◼ Mandarin
◼ Kinnow
◼ Sweet orange
◼ Valencia Late
◼ Grapefruit
◼ Periodic bearing
◼ On Year
◼ Off Year
Alternate Bearing
◼ Could be due to
◼ Nutritional imbalance
◼ C:N ratio
◼ Control Measures
◼ Off Year
◼ Heavy pruning
◼ Delayed harvesting
◼ On Year
◼ Fruit thinning
◼ Early harvesting
Granulation/Raciness
◼ Enlarged, hardened and apparently dry juice vesicles
◼ Towards stem end
◼ 1/3-1/2 of fruit is granulated
◼ Pummelo
◼ No external signs
◼ Effected fruits are heavier
◼ Granulated Juice vesicles
◼ Cell walls thicker
◼ Sugar content decreases
◼ Mineral content higher than normal
◼ Water content normal
Granulation (Contd.)
◼ Increases with
◼ Fruit size
◼ Delayed harvesting
◼ Frequent irrigation
◼ Cause is not known
◼ Most effected cvs.
◼ Mosambi, V. Late, Washington navel, pummelo and F. Early
◼ Control
◼ Spot picking of large fruits earlier
◼ Reduce irrigation
◼ Spray 2,4-D
Citrus Canker (Bacterial Disease)
Causal Organism Xanthomonas axonopodis pv. citri
Factors favouring
High humidity
disease
Temperature from 20 – 35oC
development
Use disease free nursery plants for the establishment of new
orchards.
Clip off the infected leaves before monsoon and burn them.
Disinfect the cut ends with Bordeaux paste.
Management
Dispose the infected fruit and processed fruit properly.
Spray copper oxychloride 50 WP (2-3g/L) or
50g Streptocycline + 25g copper sulphate in 500 litre of
water/acre].
Give three sprays in Feb, Oct and Dec.
Spray the nursery plants particularly during Jul-Aug.
Citrus Canker
Citrus Withertip (Fungal Disease)
Causal Organism Collectotrichum gloeosporioides
Factors favouring Neglected and poor management conditions
disease Extreme moisture, temperature around 25oC and Wind
development Disease attack on the branches, leaves and fruits
Prune and destroy the infected twigs during Late
Jan/Early Feb after harvest.
Management
Spray the plants with
Bordeaux mixture or copper oxychloride 50 WP (2-3g/L)
during Mar, Jul and Sept.
Citrus Withertip
(Fayyaz et al., 2020)
Citrus psylla
Damage of Citrus psylla Eggs and adults
Nymphs Waxy Secretions
Leaf miner
Improved phytosanitary conditions
Management Spray with suitable insecticide
(Confidor, Match etc. (1-2ml/L)
Harvesting and yield
❑ It is non-climacteric fruit
❑ Harvest when it is fully ripe (with appropriate colour, TSS, juice
contents).
❑ The best method is to pick the individual fruit by holding it in one
hand and cutting the stalk with a knife (without any leaf)
❑ The average yield expected from different types of fruits in
various species are 500 to 1000 fruit per tree (11-12 tons per
ha).
