Everything you need to learn about cultivating sapota organically. Learn about:- 1. Introduction to Sapota 2. Climate and Soil Required for Cultivating Sapota 3. Propagation and Planting 4. Training, Pruning and Canopy Management 5. Nutrient Management 6. Interculture and Intercropping 7. Harvesting 8. Pest and Disease Management.
Contents:
- Introduction to Sapota
- Climate and Soil Required for Cultivating Sapota
- Propagation and Planting of Sapota
- Training, Pruning and Canopy Management of Sapota
- Nutrient Management of Sapota
- Interculture and Intercropping of Sapota
- Harvesting of Sapota
- Pest and Disease Management of Sapota
1. Introduction to Sapota:
Sapota or sapodilla (Manilkara sapota), is an important fruit crop grown in India. It is cultivated for its delicious sweet fruits. It is native to tropical America where it is grown for its latex, which is used in chewing gum.
The fruit is a good source of digestible sugar (12-18%) and an appreciable source of protein, fat, fibre and minerals such as Ca, P and Fe. Sapota is cultivated in an area of 1,63,900 ha, with a total production of 14,95,000 tons (2012-13). Major sapota growing states are Karnataka (24.96%), Maharashtra (24.41 %), Gujarat (20.72%), Tamil Nadu (16.07%) and Andhra Pradesh (8.81%).
2. Climate and Soil Required for Cultivating Sapota:
It is a tropical fruit, which likes warm and humid (>70% RH) climate. It grows well up to an altitude of 1000m above mean sea level, however, coastal climate is ideal for sapota cultivation. Temperature range of 10-38°C and annual rainfall between 1250-2500mm is suitable for its cultivation where it flowers and fruits throughout the year. Temperature exceeding 43°C leads to flower drop.
It can be grown in a variety of soils but deep alluvium, sandy loam and well- drained medium black soils with pH 6.0-8.0 are ideal for its cultivation. However, shallow clay soils under-laid with hard pan or high calcium contents are unsuitable for sapota cultivation.
3. Propagation and Planting of Sapota:
Propagation of sapota by inarching using Manilkara hexandra (Rayan) as rootstock is the most accepted method of its commercial cultivation. One to two years old potted rayan plants with pencil thickness are utilized and grafting is done in December-January. The plants are ready for separation in June-July of following year. This method is tedious, cumbersome and time consuming. Also, plants raised through air layering establish poorly and are vulnerable to wind damage.
The technique of soft wood grafting is similar to that of cleft or wedge grafting and has been found very successful. Soft wood grafting using rayan as rootstock gives up to 93% success in-situ. July-August is ideal time for it. Grafted rootstock seedlings are covered with polythene bags. One year old rootstock plants are used for soft wood grafting. Selected scion is defoliated prior to grafting. Soft wood grafting is economically viable, faster and efficient method of propagation.
Preferably take seeds of Manilkara hexandra (Khirni or Rayan). Seeds can be taken either of rainy season crop or winter crop. To make seedlings quickly ready for grafting it will be appropriate to germinate and grow seedlings in plastic trays of 45cm x 30cm size and 10-12 cm depth and are kept in a green house.
After raising seedlings in plastic trays, seedlings are transplanted in plastic/polythene bags (12.5cm x 25cm). The main advantage of containerization is that these can be taken/shifted to green houses in order to have quick growth.
The land should be ploughed at 30-45cm depth and levelled properly to avoid water stagnation. Pits of 1mx1mx1m size are dug at a spacing of 10 m x 10 m. System of planting generally adopted is square system. The pits are allowed to weather for 15 days before planting. Planting is done preferably during early monsoon period but it can be extended up to the end of August month. Fill the pits with topsoil mixed with 30-40kg of well decomposed FYM and 500gm neem cake per pit.
Drench the soil in the pit with Trichoderma viride and Psendomonas fluorescens @10 gm/litre of water. After a gap of 2-3 days take out plant with intact earth ball from the soil in the nursery or polythene bag. Soil is scooped out in the centre of the pit and the plant is placed straight in this pit and small basin is made around the plant for regular watering. Care should be taken to see that the graft joint is at least 15cm above the ground level.
Sapota plants make uniform all round growth and square system of planting is recommended. However, in lands with 5-15% slope, contour planting is recommended. Depending on growth habit, sapota orchards are planted at 10 x 10 m. However, sapota plants being slower in growth, take longer period to occupy allotted space. Therefore, high density plantations having 5 m x 5 m spacing up to the age of 13 years are commonly planted.
Alternatively planting density of 10m x 5m or 8m x 5m can be adopted for higher returns. However, under organic management system high density planting of 5m x 5m spacing is not advisable. Wide spacing available between the rows is required for growing green manure crops, pulses and short duration vegetables and then spacing of 10m x 6m or 8m x 6m may be more appropriate for organic management conditions.
4. Training, Pruning and Canopy Management of Sapota:
Sapota plants require training for appropriate shape and frame work development. Mostly sapota trees are trained in central leader system. No regular pruning for sapota is required but regulation of vegetative growth to improve productivity and quality of fruits is necessary.
When trees become quite old, thinning of branches for opening the trees for penetration of light and aeration is necessary. Removal of diseased, criss-cross and dead branches is also required. If required topping and side dressing, can also be done for attaining the desired success in organic management system.
Sapota is grown both under irrigated and rainfed conditions. Under irrigated systems drip irrigation system is most effective and beneficial. This system needs to be laid out with 2 drippers spaced at 50 cm from plant during initial 2 years and requires to be modified to 4 drippers at 1m from plant until 5 years of age.
With dripper discharge rate of 4 litres/hr, the system should be operated for 4 hr during winter and 7 hr during summer on alternate days under Gujarat and Maharashtra conditions. Total water requirement per day will vary from location to location and will depend on soil type, prevailing temperature and evapo-transpiration.
5. Nutrient Management of Sapota:
Fully grown sapota orchard of 7-10 years of age and with 10-12 tons/ha average yield removes about 90-120 kg nitrogen, 45 kg phosphorus as P2O5 and about 100-120 kg potash as K2O. Out of this nearly 70% of N, 85% of P and 70% of K is returned to the soil in the form of fallen leaves, fruits, twigs, pruning’s etc. As sapota is evergreen and grows well round the year, luxuriant intercrop growth is possible only during the early years of planting up to 6th or 7th year.
In subsequent years intercrops can be taken mainly during rainy seasons and that too with lesser growth and biomass. One cycle of green manure crop (sunhemp, mung bean, urad bean, cowpea or Sesbania) when incorporated into the soil adds about 50-80 kg nitrogen per ha during early years of planting while in later years it may add only about 30-40 kg of nitrogen.
Keeping the soil covered with green cover from July till February-March and frequent drenching of biomass with Jivamrit can ensure sustained biological activity in the soil. In rainfed areas where irrigation facilities are not available, and taking intercrops during winter is difficult, ensure that soil remains covered with biomass mulch for moisture conservation, sustained microbial activity in the soil and for effective weed control.
As sapota flowers and fruits twice a year, application of manures is preferred twice a year, but in rainfed situations manuring is done only once just before the monsoon. For working out organic nutrient requirements of sapota, fertilizer schedule under conventional management needs to be considered which suggests for application of 50 kg FYM, 1000 gm nitrogen, 500 gm P2O5 and 500 gm K2O per fully grown plant.
Keeping all these situations in mind two different nutrient management protocols are proposed, one for rainfed dry areas, and second for irrigated humid areas where irrigation is available. For easy application prepare concentrated manure mixture by mixing 70 kg vermicompost or BD compost with 14 kg concentrated chicken manure or poultry manure, 10 kg neem cake, 5 kg wood ash and 1 kg of bio-fertilizer mixture comprising of Azotobacter/Azoispirillum + PSB + KMB + Trichoderma viride. Mix all the ingredients with some water and apply after incubating it for 48 hours. Concentrated manure mixture is most effective within 7-8 days of preparation.
For meeting the nutrient requirements at later stages plants are fed through leaves. A foliar feeding solution comprises of Vermiwash (5%) or Panchagavya (3%) or farm made protein hydrolysate (4-5 ml/lit of water). Any one or combination of two or all can be used depending upon the requirement.
6. Interculture and Intercropping of Sapota:
Frequent weeding or mulching is necessary for first few years. In established orchard, pre-monsoon and post monsoon inter-cultivation is recommended for better aeration and effective weed control.
Sapota has long pre-bearing age and till the trees cover the entire area with canopy, intercrops can be grown. This period may be as long as 5-6 years. Short duration vegetables can also be profitably grown. Legume vegetables and pulses benefit in several ways.
Later when the plants have become fully grown only legume green manure crops can be taken during rainy seasons with high seed rate. This helps in effective control of weeds in addition of biologically fixed nitrogen and substantial biomass incorporation.
For the success of intercrops please remember to apply necessary manures as basal dose needed for the growth of intercrops in specified areas at the time of field preparation for sowing. Soil and foliar application of liquid manures applied for sapota crop should also be applied on the intercrops. Similarly pest and disease management needs of intercrops must be taken care of.
7. Harvesting of Sapota:
Sapota is a climacteric fruit; it has to be ripened artificially. Fruits are highly perishable and they undergo rapid ripening changes within 5-7 days during which the fruits become soft, sweet and develop excellent aroma with decline in tannins, latex sapotin, aldehydes and acidity.
Bearing starts from 4th year onwards and economical yields can be obtained from 7th year. It takes 4-6 months from flowers to fruit maturity. March to May and September to October are the two distinct seasons of harvest. Depending on management level, location and variety, 15-20 tons of fruits are harvested from a hectare.
Harvested fruits should be cleaned of latex and scurf by washing in clean water to make them look attractive. Alternatively, harvested fruits can be placed upside down on racks for delatexing for half an hour to one hour period as is done in mango for production of quality sapota fruits. It may not be easy to remove latex stain by washing unless it is done immediately after stopping of exuding latex.
Fruits are graded into big, medium and small sizes. Fruits should be tightly packed in cardboard boxes of 10 kg capacity with rice straw as padding material and with ethylene absorbents and transported quickly to wholesale markets. Refrigerated vans should be utilized for long distance and export markets. Modified storage with 10% CO2 can help in storing fruits up to 21-24 days.
8. Organic Pest and Disease Management in Sapota:
Pest and disease management in sapota organic fanning is an integrated approach combining cultural, mechanical and biological strategies in first place and using botanical and organically acceptable chemicals only as last resort.
First and foremost strategy for organic pest and disease management in sapota is creation and maintenance of diversity, which includes permanent diversity plantation on boundary and internal bunds, (such as Gliricidia, Leucaena leucocephala, perennial pigeon pea etc. on borders) and pesticidal value plants such as Adathoda, Ipomea, Calotropis, nirgundi etc. randomly in between border plantation and aromatic grasses such as lemon grass on internal bunds and seasonal diversity through intercrops (mainly leguminous crops), flowering plants and trap crops (such as marigold, basil etc.)
Second strategy involves manipulation of cultural practices to ensure a balance in natural processes, which in turn keep the pests below the economical threshold limit.
Important cultural practices include:
1. Proper spacing, mulching and green manuring and adequate use of organic manures.
2. Do not follow close spacing or high density planting.
3. Use of resistant cultivars and disease free planting stock.
4. Growing legumes as cover/intercrop and its incorporation in soil.
5. Keeping soil covered with living vegetation and or crop residue.
6. Use of neem cake and drenching of tree basin with Trichoderma viride, T. harzianum and Pseudomonas fluorescens.
7. Do not uproot weed plants those are growing naturally and act as nectar source for natural enemies (such as Tridax procumbens, Ageratum sp, Alternanthera sp etc.)
8. Collect egg cards of beneficial insects for release such as Trichogramma, Chrysoperla, Telenomus etc. which are available from State Bio-control Labs.
9. Install pheromone traps.
10. Install yellow pan water trap/blue sticky traps 15 cm above the canopy for monitoring and mass trapping of moths.
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. Grow flowering plants along the crop border by arranging small plants towards the crop and taller plants towards border. Important insectary plants that can also be grown as intercrops and also on internal bunds include mustard, sunflower, alfalfa, marigold, carrot, French bean, cow- pea, maize, spearmint, peppermint, coriander, Ocimum etc. After flowering these plants can be used as green manure/mulch.