Everything you need to know cultivating papaya organically. Learn about:- 1. Introduction to Papaya 2. Climate and Soil Required for Papaya Cultivation 3. Plant Propagation Technique 4. Planting and Spacing 5. Intercropping and Interculture 6. Organic Nutrient Management 7. Thinning and Harvesting 8. Insect Pest and Disease Management 9. Varieties.
Contents:
- Introduction to Papaya
- Climate and Soil Required for Papaya Cultivation
- Plant Propagation Technique of Papaya
- Planting and Spacingof Papaya
- Intercropping and Interculture of Papaya
- Organic Nutrient Management of Papaya
- Thinning and Harvesting of Papaya
- Insect Pest and Disease Management of Papaya
- Varieties of Papaya
1. Introduction to Papaya:
Papaya (Carica papaya) belongs to the family Caricaceae produces fruits throughout the year. Papaya is a native of tropical America. It is now grown in all the tropical and subtropical countries. Papaya is cultivated in India in an area of 132 thousand ha and the production is around 5,382 thousand tons.
The main papaya producing states in India are Andhra Pradesh (30.7 %), Gujarat (22.1%), Karnataka (8.6%), Madhya Pradesh (7.7%), Maharashtra (6.7%), West Bengal (6.2%), Chhattisgarh (5.4 %), Tamil Nadu (3.4%), Assam (3.2%), Kerala (1.8%) and other states (8.2%).
Papaya being very heavy nutrient feeder, papaya cultivation under organic management is not recommended as sole crop and is best cultivated under mixed crop strategy. Small and marginal farmers in south India grow papaya as shade crop in nurseries, coffee plantations, as an intercrop between coconut and with pineapple.
Papaya can also be grown as mixed crop with cassava and elephant foot yam as intercrops. In other parts organic papaya can be grown as main crop and various green leafy vegetables and legume crops as intercrops. Some vegetables such as green pod legumes can also be taken as intercrops with papaya.
2. Climate and Soil Required for Papaya Cultivation:
Papaya is a tropical fruit; however, it also grows well in the mild subtropical regions of the country up to 1,000m above mean sea level. Temperature is one of the most important climatic factors, which determines the success of papaya cultivation. Night temperatures below 12.0- 14.0°C for several hours during winter season affects its growth and production severely. It is very much sensitive to frost, strong winds and water stagnation.
It can be grown in a wide variety of soils, provided these are well drained and aerated. A rich well drained sandy loam soil is ideal for its cultivation. It can also be grown in calcareous and stony soils provided with heavy dose of organic manures. Soils with pH 6.5 to 7.0 should be preferred for its cultivation.
3. Plant Propagation Technique of Papaya:
Papaya is commercially propagated by seeds. The seed rate is 250-300 g/ha. It is possible to raise sturdy plants in the nursery. In the case of papaya, a good nursery can supply healthy seedlings free from diseases or disorders and having uniform and true to type character.
Extraction of Seeds:
Since papaya is a cross-pollinated crop, seeds should be obtained from reliable sources where controlled pollination is practiced. Select the seeds from plants, which are healthy and vigorous, and bear good quality fruits, having thick flesh with attractive size, colour and shape.
Fruits should be harvested for seed production at 110-129 days after anthesis when fully matured. Seeds used for raising the seedlings should be fresh. Sowing of seeds immediately after extraction, but after full cleaning and drying in the shade, gives maximum germination.
The seeds should be rubbed with wood ash and dried in shade. They can be stored for months retaining their viability, if they are kept in clean and airtight bottles. Storage of seeds at 10°C is also effective for maintaining seed viability.
Preparation of Nursery Bed:
In general, papaya seedlings are grown in raised beds under open conditions. Papaya seedlings raised in the open get infected from soil born diseases like Pythium sp., Fusarium oxysporum etc. Also rains and frost affect such seedlings during winter. Moreover papaya seedlings usually also get infected with virus diseases because of infestation of vectors i.e. aphids and white flies.
Therefore, best alternative is to raise papaya seedlings in containers placed in a net house/green house in order to obtain disease free quality papaya seedlings. Plastic trays of the size 45 x 30 x 12 cm are used for sowing of seeds.
Media for germinating seeds can be prepared by mixing virgin loam soil, sand and F.Y.M./compost (1:1:2) and sterilizing it by covering with a white polythene sheet (200 gauge) in summer (April to June) months for 3-4 weeks. It can be further treated by drenching with Pseudomonas fluorescens and Trichoderma viride solution @ 250 g each in 20 litres of water to eliminate remaining infection if any. This media can be filled in plastic trays or polybags.
Sowing of Seeds and Seed Germination:
Fill the plastic trays/plug trays with sterilized media. Plastic trays of the size 45x40x12 cm and plug trays of 74 to 82 holes of 4.5 cm each in diameter can be used for the purpose and 250-300 g seed is enough for one hectare. Soak the seeds overnight in Beejamrit and treat the seeds with Trichoderma viride and Pseudomonas fluorescens @ 18-20 g for 250 g seeds.
Alternatively seeds can also be treated with garlic, clove and cinnamon extract or dry turmeric powder + Asphoetida powder mixture. Seeds need to be sown 1cm deep and in 8-10 cm wide rows. Keep the trays in net house/green house and irrigate as per requirement. To control diseases, drench the seedlings with Trichoderma viride and Pseudomonas fluorescens @5-10 g/litre of water.
Transplanting Seedlings in Polybags:
Transplant the seedlings in polybags when these attain the height of 5-6 cm. Polybags of the size 25 x 15 cm of 150-200 gauze thickness can be used and these can be filled with sterilized media and are kept in screen house/green house after transplanting.
Treat them with bio-fungicide solution (by drenching) against diseases and with neem oil (3-5%) against insect pest if any. Polybags must be kept in net-house/greenhouse to protect against vectors. When the seedlings reach the height of 20-25 cm they are fit for planting in the field.
4. Method of Planting and Spacing of Papaya:
Papaya can be planted during spring (February-March), monsoon (July- August) and autumn (September-October). But during July -August months infestation of virus diseases takes place because vectors are pre-dominant during this season. Therefore, planting either during September-October or during February-March should be preferred.
Pits of size 60 x 60 x 60 cm are dug in summer months to expose to sun. Topsoil of the pit is mixed with 5 kg well rotten FYM, 1 kg vermicompost, 500 gm neem cake, 500 gm bone meal, 1000 gm wood ash and 25 gm each of Trichoderma viride and Pseudomonas fluorescens. All the manures are properly mixed and a light irrigation is given. After 1 -2 days, papaya seedlings are planted. In case of dioecious plants 2 or 3 seedlings per pit are planted and for gynodioecious, one seedling per pit is planted.
As high density plantation is not a preferred mode under organic management, seedlings are planted at a distance of 1.6-1.8 mt from plant to plant in a row. Row-to-row distance is maintained at 2.5 to 3.0 m, leaving a strip of about 1.5 meter for intercrops. This will provide a planting density of about 1800 to 2500 plants per ha.
5. Intercropping and Interculture of Papaya:
Deep hoeing is recommended during first year to check weed growth. Hoeing should not be done in rainy season or after fruiting since its plants are shallow rooted. Overgrowth of weeds also causes waterlogging condition and makes the plants vulnerable to root rot and foot rot in rainy season.
Therefore weeding should be regularly done, especially around the plants. Growers may mulch the bed with the plastic film before transplanting or with rice/sugarcane straw before or within a few days after transplanting to control the weeds, soil erosion and water loss. Earthing up is done before or after the onset of monsoon to avoid water logging and also to help the plants to stand erect.
Intercropping between papaya is an important strategy under organic management and to facilitate intercrops the spacing between two rows is kept at 2.5-3.0 meters. With remunerative intercrops this distance can be increased even up 3.5 meters. In south India papaya is generally grown as an intercrop with arecanut and coconut.
Cultivation of papaya as main crop and elephant foot yam/cassava or colocasia as an intercrop has been found to be profitable. Papaya can also be grown as shade crop in nurseries to provide protection for young plants of various orchard species.
In central Indian plains, cultivation of papaya as main crop and cowpea, French bean or cluster bean and lab as intercrops have been found highly profitable and at par with sole papaya plantations under conventional management. Another intercrop combination found highly profitable with papaya is soybean/cowpea followed by onion on raised beds or green pod legumes followed by green leafy vegetables such as Trigonella (methi) or coriander for leaves between two papaya rows.
Some other crops which can be taken up as intercrops with papaya during first 3-5 months are – sunhemp, radish, French bean, carrot, beet root, leafy vegetables such as spinach and chaulai (Amaranth). However intercrops requiring frequent irrigations need to be avoided as it may result in infestation of Phytophthora foot rot. Intercrops also require due care for nutritional and pest management point of view and must be taken care of.
Cucurbitaceous vegetables such as cucumber, long gourd, ridge gourd, round gourd, sponge gourd etc. need to be avoided not only from the fields of papaya but also from the close vicinity as they can increase the risk of virus diseases. Cucurbits also serve as alternate host to virus vectors, therefore keep all cucurbits away.
The planting of intercrops follows planting of papaya. Care must be taken that intercrops are planted at least 0.50 meter away from the papaya seedlings. In cases where row-to-row distance is 3.0 meters then intercrops can be grown in 1.5 meter strip and where distance is 3.5 meters the intercrops can be grown in 2.0 meter strips between two rows during first three months and then in strips of 0.5-1.5 meter strips.
Besides the intercrops some insectary plants such as marigold, Hibiscus, tuberose etc. may also be inter-planted in between and on the borders all around the papaya field. Two rows of citronella grass all around the papaya field repels aphids and other flying insect pests.
Irrigation:
Papaya responds well to better water management by rapid development of fruit and supply of fruits regularly. Regular irrigation helps in fruit development and induces the tree to bear a number of fruits with larger size. Irrigation may be given once in 8-10 days in winter and 6 days in summer. Manure application should be done in presence of moisture.
However, excessive water leads to waterlogging conditions, which are very harmful for the plants. The ring system of irrigation is better than the bed or basin system as it prevents collar rot disease. Trenches may be dug between plant rows during monsoon to avoid water stagnation in the field. In areas having low rainfall, sprinkler or drip system can be adopted.
6. Organic Nutrient Management of Papaya:
With optimum productivity each papaya plant removes approximately 160- 175 gm of N, 60-70 gm of phosphorus and 300-350 gm of potassium, out of which nearly 75% of N and 90% of phosphorus can be returned back to the field in the form of leaves, flowers and thinned fruits, which can be recycled back through composting and/or mulching.
In case of potash nearly 50% is permanently lost in the form of harvested fruits. In case of calcium and magnesium, although removal is almost 120 gm and 70gm respectively but over 90% of Ca and Mg are recycled back to the field through fallen leaves, flowers and fruits etc. This removal pattern is to be kept in mind while calculating the need for nutrient management from external sources.
Recycling of biomass and mulching should act as the major nutrient source and it is to be ensured that waste biomass of papaya and the left over biomass of intercrops is recycled back either as compost or as mulch. Care should be taken to mulch the space between rows at least 50 cm away from the papaya plants. Drench the mulch layer with Jivamrit @ 200 litres/acre.
As organic farming systems emphasize on feeding the soil rather than feeding the plant, in nutrient management, stress is laid on recycling of biomass, using open spaces for leguminous cover crops for green manuring, using liquid manure such as Jivamrit and bio-fertilizers for hastening microbial process and compensating the shortfall with the use of FYM/compost, vermicompost, concentrated manures and wood ash (or sulphate of potash in case ash is not available). To ensure high use efficiency of applied manures, neem cake is also applied mixed with organic fertilizers.
Calculating the Nutrient Needs from External Sources:
Considering the quantity of biomass and nutrients being recycled the short fall is calculated and applied as combination of various organic inputs. For calculating organic nutrient requirement, application of fertilizers under conventional management should also be considered. Usually under conventional management 250-300 gm nitrogen, 200-250 gm P2O5 and 400-500 gm K2O per plant per crop are added.
After considering all aspects and taking into account that entire intercrop biomass and later papaya waste biomass is recycled approximately 20-25 kg of FYM/compost is to be added in two splits and 12-15 kg nutrient rich organic manure mixture is to be provided in 4-5 split doses per plant. Foliar feeding in the form of foliar sprays is also essential at frequent intervals starting from 150 days of planting till 9th month of planting.
Preparing Organic Manure Mix:
For preparation of every 100 kg of nutrient rich organic manure mixture, mix following organic nutrient materials in quantities mentioned against each:
Mix all ingredients thoroughly using about 5-10 lit of water. Keep aside for 24-48 hrs for incubation. Use the mixture within 4-5 days of preparation. If available 100 gm of CPP can also be mixed with the above mixture for better results.
In case if wood ash is not available then use sulphate of potash. 150 gm sulphate of potash equals 1 kg wood ash.
7. Thinning and Harvesting of Papaya:
Thinning of fruits becomes essential in papaya when several fruits set in a cluster instead of a single fruit at each node. The operation is performed immediately after fruit set and involves thinning or removal of the fruit clusters, leaving not more than two fruits at each node. This prevents the damages to fruits due to over- crowding and their competition for nutrients and fruit drop.
Harvesting:
Papaya fruits will be ready for harvest by about 9-10 months after planting depending on cultivar and prevailing temperature during the course of fruit development. The change of colour from green to yellow and the consistency of the latex from milky to watery indicate that the fruit is ready for harvest. This stage is also called colour break stage.
The ripe fruit is harvested individually by hand picking taking care to avoid all possible injuries. The mature fruit easily gets detached from stem either by turning it upwards or by twisting. The fruit should be harvested early in the morning and kept in shade for grading.
Average yield is about 50-55 tons per hectare.
Post-Harvest Handling:
Papaya is a very delicate fruit and due to its perishable nature it is very prone to post-harvest injuries. Therefore careful handling must be adopted during harvesting, handling and transportation.
Papaya fruits are easily damaged after harvest due to dropping in crates or due to overfilling in crates and fruits get bruised. Cushioning material needs to be used in crates at the base and sides to avoid it. Only one layer of fruits needs to be used. Papaya fruits in crates are kept in shade and shifted to pack house as soon as possible.
For long distance transfer or export, the papaya fruits are washed in the pack house with chlorinated water (75-100 ppm chlorine) and then rinsed in clean water. After this the fruits are sorted and damaged and bruised fruits are rejected. Good fruits are treated with hot water at 49°C (in a hot water bath) for 20 minutes. Immediately after this fruits are dipped in cold water at 12-15°C for 10 minutes.
After shock treatment with cold water fruits are cured and then graded and packed in cardboard boxes and pre-cooled. Fruits can be stored for 1-3 weeks in a cold store at 10-12°C and 85-90% relative humidity.
8. Organic Insect Pest and Disease Management of Papaya:
Organic pest management in papaya is an integrated approach combining cultural, mechanical and biological approaches with major emphasis on problem avoidance, pest repellence, and biological strengthening of control agents and keeping the soil healthy with adequate manuring. Healthy soils, use of resistant varieties, using disease free seeds, raising seedlings in disease free environment are some of the important preventive strategies.
Seed treatment with Trichoderma viride and Pseudomonas fluorescens and solar sterilization of potting medium followed by drenching of medium with T. viride and P. fluorescens prevents all seed borne and soil borne diseases.
Maintenance of proper spacing, mulching and manuring at scheduled intervals also helps in effective management of pests and diseases.
Some of the important ecological and cultural strategies found effective in containing the pest and disease problems below economical threshold level (ETL) are as follow:
1. Do not allow cucurbit vegetables in and around papaya plantations
2. Frequent growing of legumes as intercrops and mulching of their biomass along with some other crop residue and weed residue
3. Adequate use of organic manures followed by biomass mulching and drenching of biomass with fermented dung-urine slurry (such as Jivamrit) ensures high activity of beneficial microbes that act as deterrent to harmful microorganisms and insects.
4. Ensure creating biodiversity by planting of nitrogen fixing plants like Gliricidia, Leucaena leucocephala etc., fruit plants like ber etc. on borders and pesticidal plants such as Ipomea, Vitex (nirgundi) etc. and aromatic grass like citronella planted randomly in between border plants.
5. Ensure natural habitat and survival conditions for natural pest enemies such as pest predators, parasites and pathogens.
6. Raise the flowering plants as trap/insectary crops along the field border by arranging shorter plants towards main crop and taller plants towards the border to attract natural enemies as well as to avoid immigrating pest population. Important insectary plants that can be used as intercrops and also can be planted on bunds include mustard, sunflower, buck wheat, alfalfa, marigold, carrot, French bean, cowpea, maize, coriander, spearmint etc. After flowering these plants can be used as green manure/mulch.
7. Select and plant appropriate companion plants, which could be trap crops and insect attractant plants. The trap crops and insect attractant plants will also recruit natural enemies as their flowers provide nectar and the plants provide suitable microclimate.
8. Release and protect beneficial insects such pest predators and parasitoids such as ladybird beetle, hover fly, green lacewing, spiders, predatory mites, Bracon hebetor and Trichogramma.
9. Pheromone traps for fruit fly @ 4-5/acre for each species separated by a distance of >75 feet in the vicinity of the field. Fix the traps to the supporting pole at a height of one foot above the plant canopy. Lures need to be changed at 2-3 weeks interval (regular interval). During each week of surveillance, the number of moths/trap should be counted and recorded. The trapped moths should be removed and destroyed after each recording.
10. Install yellow/blue water pan and sticky traps at a height of mid canopy @ 4-5 traps/acre for observations and 20-25 traps/acre for control.
11 Set up light traps @ 1 trap/acre 15 cm above the crop canopy for monitoring and mass trapping insects. Light traps with exit option for natural enemies of smaller size should be installed and operate around the dusk time (6 pm to 10 pm).
12 Apply mycorrhiza and plant growth promoting rhizobacteria (PGPR).
13. Apply Trichoderma viride/harzianum and Psendomonas fluoresceins as seedling and pit/soil treatment
14. In case if there is problem of nematodes then also apply Paecilomyces lilacinus as soil treatment along with neem cake.
Keep on watching the pests to defender ratio, which is generally maintained at 2:1.
9. Varieties of Papaya:
A large number of varieties or types are found in papaya due to its propagation by seed and cross-pollinated nature, resulting in wide variation in varieties. However, through controlled pollination and selection, few varieties true to the type have also been evolved. Two types of varieties are available in papaya, which are dioecious and gynodioecious.
Dioecious types produce male and female plants in 1:1 ratio when multiplied by seeds. Whereas gynodioecious types produce female and hermaphrodite plants in a ratio of 1:2. Usually gynodioecious varieties are preferred as in such varieties all plants are bearing plants.