Introduction to papaya
| Common name | Papaya |
| Scientific name | Carica papaya |
| Another name | Apple of paradise |
| Family | Caricaceae |
| Origin | Tropical America |
| Chromosome number | X = 9, 2n =18, 36 |
| Fruit Type | Berry |
| Edible portion | Mesocarp |
Also read: Grape Cultivation: Varieties, propagation, and diseases
Importance
- It is highly nutritive and has medicinal value.
- Tropical or sub-tropical crop.
- It is fifth most important fruit crop grown in India.
- Papain is a protein digestible enzyme. Immature papaya is the source of papain.
- Enzyme pepsin is found in papain.
Climate and soil
- Topography: It can be grown up to 1000 m above MSL.
- Summer season: Temperature range is 30-37 °C.
- In winter, temperature below 10 °C is not suitable for this crop.
- The crop is very much sensitive to frost, strong winds and water stagnation.
- Well drained sandy loam soil with high organic matter is ideal for its cultivation.
Soil
- Optimum soil pH is 6.5-7.0.
- Upland areas should be preferred.
- Waterlogged condition is not suitable.
Propagation and planting
- Commercial production: Seed.
- Tissue culture or micro propagation is also used.
- Seed rate: 250-300 gm/ha.
- Planting time
- Spring season: February to March.
- Monsoon season: June to July.
- Autumn season: October to November.
Also read: Scientific Cultivation of Pineapple
Spacing
- General spacing: 1.8 × 1.8 m.
- Coorg Honey dew: 1.33 × 1.33 m.
- Pusa delicious: 1.4 × 1.4 m.
- Pusa Nanha: 1.2 × 1.2 m.
Interculture operations
Intercropping
- In intercropping, it can be grown with tobacco, gram, pea etc.
- In intercropping, crop like chilly, tomato, brinjal, okra should not be taken as they act as a virus host.
Weed control
- Application of Butachlore, Alchlorine, Plachloralin (2 gm/ha) as pre emergence herbicides after 2 months of transplanting for effective control of weeds.
- Removing of unwanted male plants is necessary for good pollination where dioecious varieties are cultivated.
- The male plant in a papaya orchard for good pollination should be 10%.
Manure and fertilizers
- NPK: 200 to 250 gm per/tree/year.
- For papain yield, dose of N is 300 gm.
Irrigation
- Soil moisture is essential for growth, yield and quality of fruits.
- If moisture is less, floral sex shifts towards female sterility those results in poor yield.
- Over irrigation results root rot disease.
- Number of irrigation depends upon soil type, variety and weather conditions.
- Irrigation are generally given at 15 days interval in winter and 10 days interval in summer.
- Commonly used irrigation system is asin system.
- Under water scarcity condition sprinkler or drip system is a better option.
- Papaya plants are susceptible to water stagnation condition.
Thinning
- It is an operation of removal of undesirable fruits to obtain better quality of fruits.
- Fruits (undesirable) are removed when they are 3 cm long.
- Thinning should be done in such a way that no fruits touch each other.
- Excess thinning reduce yield.
Optimum thinning increases quality fruits yield and market value.
Also read: Mango Plantation: Cultivation Practice and Orchard Management
Harvesting
- Papaya plant start flowering in 5-6 months after transplanting.
- After flowering, they take another 5 months for harvesting.
- Fruits are harvested when they are firm (hard) and latex is no longer milky and watery.
- Change of colour of fruits from dark green to yellow is another parameter of harvesting stage.
- Economical bearing for papaya crop is 3 years, so after every 3 years papaya orchard should be replaced.
- On an average, improved variety gives 30-45 fruits per tree.
- On an average, yield 60-75 tones/ha.
Varieties
Some important varieties are
Pusa Delicious, Majesty giant, Nanha, Dwarf, honey dew, Coorg Honey dew, Washington, CO 1 and CO 2.
Varieties for specific purposes
- Pusa delicious: Excellent taste and flavour.
- Pusa majesty: Best for papain production.
- Pusa nanha: Suitable for HDP.
- CO-3: high sugar content and suitable for desert region.
- CO-4: Suitable for home gardening.
- CO-6: Selection from Pusa majesty and used for both papain and desert purpose.
Gynodiocious variety
Pusa delicious, Pusa majesty, CO-3, Coorg Honey dew (selection from Honey dew, Hermaphrodite, for South India), Sunrise, Taiwan (Blood red Colour), Surya.
Dioecious variety
Pusa giant (Used in Canning industry), Pusa dwarf, Pusa Nanha (extremely dwarf), CO-1, CO-2, CO-5 (Cultivated mainly for papain extraction), CO-6 (selection from Pusa majesty), Pant C1, Sunny bank, Improved petron.
Hybrid varieties
- CO-3 = CO-2 × Sunrise Solo
- CO-4 = CO-2 × Washington
- CO-7 = CO-3 × Pusa delicious × Coorg Honey dew.
- On an average TSS value of papaya is 12-14 Brix.
Insect-pest
Papaya stem borer
- Dasyses rugosollus a caterpillar bores into the stems.
- Cut and destroy the affected parts or spray 4 % carboxyl.
Fruit fly
- Dacus diversus
- Female flower attract male of this fly.
- Use 20 gm malathion 50 % WP or 50 ml Diazenone with 200 gm molasses in 2l of water.
Disease
Papaya mosaic virus
- Vector is aphid. It is always advisable to control vector instead of controlling virus directly.
- Remove and destroy infected plant parts.
Papaya leaf curl virus
- Vector is aphid.
- It is always advisable to control vector instead of controlling virus directly.
- Remove and destroy infected plant parts.
Miscellaneous
- Seed rate for gynodiocious variety is 250 to 300 gm/ha.
- Seed rate for diocious variety is 400 to 500 gm/ha.
- Yellow pigment in papaya is due to caricaxanthin.
- Test weight of papaya seeds is 50 gm.
- Most serious disease in papaya is damping off.
- Papaya is a thermosensitive crop.
- sunrise sols does not produce any male plant
- It is the second rich vitamin A fruit after mango.
- Satellite chromosome in papaya controls the maleness.
- Seeds can be stored at 10 degree celcious in an air tight bottle for 9 months.
- Seed treatment with thiourea (100 to 200 ppm) or GA3 improve seed germination.
- Pusa nanha is a mutant developed variety produced through gamma radiation.
- Drip irrigation in papaya saves 50 to 60 % of water.
- Water requirement in papaya is 1800 to 1900 mm.
- Carica qucrcifolia is the hardiest spp. of papaya.
- Carica monoica is a monoecious spp.
- Carica cauliflora, Carica microcarpa, Carica candamarcensis are cross incompatible variety with Carica papaya.
- Powdery mildew is due to oidium caricae.
- Stem and foot rot disease is due to phytopthora aphanidermatum and rhizoctonia solani.