Everything you need to learn about cultivating pomegranate organically. Learn about:- 1. Introduction to Pomegranate 2. Climate and Soil Required for Pomegranate 3. Propagation 4. Planting Technique 5. Training, Pruning and Canopy Management 6. Organic Nutrient Management 7. Orchard Management Practices 8. Intercropping and Grading 9. Insect Pest and Disease Management.
Contents:
- Introduction to Pomegranate
- Climate and Soil Required for Pomegranate
- Propagation of Pomegranate
- Planting Technique of Pomegranate
- Training, Pruning and Canopy Management of Pomegranate
- Organic Nutrient Management of Pomegranate
- Orchard Management Practices of Pomegranate
- Intercropping and Grading of Pomegranate
- Insect Pest and Disease Management of Pomegranate
1. Introduction to Pomegranate:
Pomegranate (Punica granatum L.) belongs to the Punicaceae family and is one of the oldest edible fruits. It is being cultivated extensively in mild temperate and subtropical regions under arid and semi-arid conditions. Pomegranate does best under hot dry summer and cool winters. Pomegranate fruit is consumed fresh or as processed into juice and syrups. The edible part of the fruit is called arils.
The total area under cultivation of pomegranate in India is 1,13,000 hectares with a production of 7,45,000 tons (2012-13). Maharashtra is the leading producer of pomegranate (54.8%) followed by Karnataka (20.2%), Gujarat (10.6%) and Andhra Pradesh (8.3%).
2. Climate and Soil Required for Pomegranate:
Pomegranate can be grown up to an altitude of 500 m. above sea level. The tree requires hot and dry climate during fruit development and ripening. Pomegranate tree is deciduous in areas of low winter temperature and an evergreen or partially deciduous in tropical and subtropical conditions. For proper fruit development, maturity and sweetness, a temperature of 35-38°C is needed. It can tolerate frost to a considerable extent in dormant stage.
The pomegranate is not very particular about its soil requirement and can be grown on diverse types of soils. The plant gives very good yield in deep loamy and alluvial soil and it can tolerate slightly saline soils and does well even in calcareous or rocky shallow soils. It can also be grown in medium or light black soils of at least 60cm depth.
3. Propagation of Pomegranate:
Propagation by seed is discouraged because the plants raised from seeds do not bear fruit of uniform quality. Propagation by air layering method is commonly used for multiplying the pomegranate plants, however with air layering only a limited number of plants can be multiplied. Propagation by hardwood cuttings is another method of multiplication of plants in pomegranate, but success is low in the absence of mist house facilities having high humidity.
Apart from this there is problem of infestation of soil borne pathogens like Rhizoctonia sp., Fusarium oxysporum and root knot nematode (Meloidogyne incognita) in both detached air layers as well as hardwood cuttings, when plants are multiplied in open beds. To avoid this, polythene bags of the size 12.5 cm x 25 cm filled with solar sterilized media (virgin soil, sand and vermicompost 1:1:2) need to be used for detached air layers as well as hardwood cuttings.
Further for good root development, the polythene bags having air layers or hardwood cuttings are required to be kept in green house having mist facilities. Both for air layers as well as for hardwood cuttings, plants, which are healthy, and having record of high yields need to be selected. For hardwood cuttings, 7- 9 inches long cuttings having 2-3 nodes are prepared from one year old wood.
Cuttings can be taken in January or May-June or October-November months. Air layering should be done during rainy season and November-December, which results in better success with more number of roots/layer. It is expected that with robust root growth the air layers as well as rooted cuttings raised under mist facilities will show high percentage of survival in the field.
With the intensive cultivation of pomegranate, problem of diseases like bacterial blight, wilt etc. have increased manifold. Thus there is a huge demand for disease free planting material of pomegranate, especially free from bacterial blight.
Considering the situation, protocol for in-vitro propagation of cv. Bhagwa pomegranate has been standardized by National Research Centre on Pomegranate, Solapur using green nodal segments of 2-2.5 cm length. Later tissue culture raised plants are bio-hardened followed by secondary hardening to achieve better success in establishment in the field.
4. Planting Technique of Pomegranate:
Spacing, Planting Density and Planting Technique:
Land Preparation:
The land selected for pomegranate cultivation is thoroughly and deeply ploughed followed by 3 to 4 cultivations and harrowing.
As diversified, mixed and intercropping is the rule of organic management, planting density needs to be ascertained with the cropping mix selected. Although, under conventional system 5m x 5m (400 plants/ha) is a normal spacing for the pomegranate cultivation and under high density planting a spacing of 5m x 2m (1000 plants/ha) is also adopted.
Mostly plant spacing and planting density at 4.5 m x 3 m (740 plants/ha) or 4.5 m x 2.5 m (888 plants/ha) are being adopted. But in organic system pomegranate planting is generally interspersed by other fruit plants such as sweet orange, drumstick, ber, custard apple etc. Adequate space is also kept for aeration and light penetration for intercrops.
In Andhra Pradesh some organic farmers are planting one row of mosambi after every two rows of pomegranate with random planting of drumstick plants in mosambi rows. Distance between pomegranate plants is kept at 4 m, mosambi plants at 5 mt and between two rows at 4.5-5 meters. Although high density plating with 700-800 plants per hectare in mono-cropping is also possible but in such cases the requirements for organic nutrient sources will be high.
Moreover, with intensive cultivation, disease intensity, particularly of bacterial blight and leaf and fruit spots increases, therefore high density planting under organic management is not advisable. A spacing of 5.0m x 4.0m with planting density of 500 plants/ha is most ideal under such situations. With this spacing, legume crops such as green gram, black gram, green manure crops like sun-hemp and cluster bean can be grown. Green manure crops can be ploughed in soil at tender stage for keeping the soil biologically active.
Fill the pits with top soil mixed with 30-40 kg well rotten FYM per pit. Pseudomonas fluorescens and Trichoderma viride @ 100 gm/pit is also mixed with FYM in addition to 2-3 kg neem cake per pit. After filling the pit, watering is done to allow soil to settle down. If there is termite problem Beauveria basslana @ 30-40 gm/pit is mixed in F.Y.M.
Take out the plant carefully by cutting the polythene during monsoon period. Irrigation is provided immediately after planting.
Some farmers irrigate pomegranate plantations using conventional basin system of irrigation, but drip irrigation has been found superior over basin system of irrigation in terms of yield and fruit quality. Under Maharashtra conditions drip irrigation at 0.75 CPE has been found ideal.
5. Training, Pruning and Canopy Management of Pomegranate:
Pomegranate is trained as bush. Pomegranate plant has a tendency to throw out lot of suckers and thus is not trained on a single stem. Usually, 3-4 stems are allowed per plant and they are pinched at a height of 1 meter and from below the pinched tip of each stem, 2-3 branches well distributed in all directions are encouraged.
In organic pomegranate, as penetration of light and aeration is also to be kept in mind and for growing intercrops and cover crops in between it is very important to take up appropriate pruning to avoid unnecessary crowding of branches.
In addition criss-cross, dried, diseased, broken, water sprouts and weak branches need to be removed regularly. Size controlling of plants can also be done if there is congestion in the plants. Many farmers adopt topping, side dressing and thinning of shoots after harvest to permit air circulation and increased light penetration.
This also helps in containing the pests and diseases in plantation. Keeping canopy open and in appropriate shape is necessary to have good quality fruits in terms of colour and fruit size. Another important aspect of pruning is that it should be done in such a manner that there is balanced fruit load on the plant. Heavy pruning should be avoided as it may expose the fruits to sun and reduce yields. It is advisable to spray Bordeaux mixture (4:4: 500) to minimize infestation by diseases. Also disinfect pruning tools in 1% sodium hypochlorite solution.
6. Organic Nutrient Management of Pomegranate:
A pomegranate orchard with an average productivity of 10 MT/ha removes approximately 34 kg nitrogen, 6 kg phosphorus and 52-55 kg potash besides 14 kg calcium and 2 kg magnesium in the form of fruits. Even if rest of the biomass is recycled back to the soil, adequate quantity of nutrients needs to be replenished so that plants can absorb the above mentioned quantity of nutrients.
To meet the productivity target in pomegranate under conventional management use of 30-40 kg FYM along with 625 g N, 250 g P2O5 and 500 g K2O is recommended for 5 year old or above plants and entire quantity of FYM along with phosphorus and potassium and half of nitrogen is applied at first irrigation after bahar (water stress) treatment and rest of the nitrogen is applied after fruit set.
Low growing leafy vegetables and legumes can be successfully grown between pomegranate plants. Cover crops also play very important role in biological nitrogen fixation and management of weeds. In rainfed dry areas one crop of legumes during rainy season can add upto 50-60 kg biologically fixed nitrogen with adequate quantity of organic matter for sustained microbial activity in the soil.
Under irrigated condition one cycle of green manure crop and one cycle of green leafy/legume vegetables can be grown and their biomass is mowed in the soil or used as mulch below the plants in a ring about 30-40 cm away from the tree trunk.
Keeping in view of above and assuming that entire fallen leaves, dropped fruits, pruning’s etc. have been recycled as mulch and at least one cycle of green manure crop has been incorporated in the soil. As the nutrient requirement from organic sources cannot be met with one or two nutrient sources, a mixture of different nutrient sources are used as soil application and as foliar feed in the form of foliar sprays.
The composition of concentrated manure mixture and foliar feeding solution is as follows:
Preparing Concentrated Manure Mixture:
For preparation of every 100 kg of nutrient rich concentrated 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.
Foliar Feed Solution:
Feeding plants through leaves is an important strategy in organic farming. Vermiwash (5%), Panchagavya (3%) and farm made protein hydrolysate (4-5 ml/lit of water) are ideal inputs. Any one or combination of two or all can be used depending upon the requirement.
7. Orchard Management Practices of Pomegranate:
Mulching and Soil Moisture Conservation:
Pomegranate is cultivated in water scarce areas and therefore soil moisture conservation is very important. Use of sugarcane husk or paddy husk or dry grass mulching has proved very effective. Soil moisture conservation will also help in decreasing diurnal fluctuation in soil temperature and helps in reduction of fruit cracking.
Pomegranate plant can flower throughout the year depending upon the climatic conditions. However, three main flowering seasons are distinct viz. Ambe Bahar (Feb.-March), Mrig Bahar (June- July), and Hasth Bahar (September-October).
In pomegranate, fruit load on the plant immediately reflects on the fruit size or fruit weight. Thus higher fruit load on the plant will result in smaller and immature fruits. Usually farmers plant 750 to 1000 plants per hectare. Hence fruit load on the plant will vary with age of the plant and planting density. A fully grown plant is usually retained with 50-70 fruits per plant.
Harvesting and Yield of Pomegranate:
The fruits are harvested when the skin attains distinctive colour characteristic of variety and the fruit gives a metallic sound when tapped. The fruits become ready for picking in 120-130 days after fruit set.
The calyx at the distal end of the fruit gets closed on maturity and the pomegranate fruits are usually hand-picked. Yield in pomegranate depends on variety, planting density and cultivating practices adopted. On an average yield of the order of 7-8 tons to 10-12 tons per hectare can be obtained.
After receipt of pomegranate in the pack house fruits are sorted. All fruits showing greenish colour, fruits with sun spots, affected by fruit borer or having disease spots or russeting etc. are eliminated. Also fruits having cuts, blemishes etc. are rejected.
8. Intercropping and Grading of Pomegranate:
Low height legumes like green gram and black gram and cover crops can be taken up successfully. Intercrops and cover crops are mainly taken for biological nitrogen fixation, soil fertility enhancement and soil moisture conservation and needs to be ploughed in the soil at tender stage.
Cover crops like berseem, methi etc. also help in effective management of weeds and minimising diurnal fluctuation in soil temperature. However, nutrient needs and pest and disease management requirement of intercrop must be met at the appropriate time.
After sorting, the fruits are graded either manually or with the help of a size grader. Details of different grades adopted are given below in Table 71.
Cleaning:
After sorting, before packing pomegranates in a box, fruits at calyx side are wiped with a cloth soaked in bleach solution (80-100ppm chlorine) to avoid contamination in a packed box.
For packing, mostly 4.0kg or 5.0 kg box is used and fruits 10 to 20 in number are packed in a box depending upon the fruit size. The dimensions of 4.0 kg box are 375x275x100 mm and that of 5.0 kg box are 480x300x100 mm. For cushioning either paper shreds or cardboard partitions are used to avoid movements of fruits within the pack.
For safeguarding the fruits from injury, bubble plastic is used and is placed at the bottom, sides and top of the fruits. Placement of fruits in boxes is generally done by putting accurate sized fruits and keeping some cushioning material in between to avoid movement of fruits in transportation.
Pre-Cooling and Cold Storage:
Before storage, pomegranates need to be pre-cooled by forced air cooling at 5-7 °C. Ideal temperature for storing is 5-7 °C at 90-95% RH.
9. Organic Insect Pest and Disease Management for Pomegranate:
Creation and maintenance of diversity, growing cover crops during rainy season and keeping soil covered with biomass mulch is the most effective strategy in pest management. Planting of nitrogen fixing plants such as Gliricidia and also maize on the outer borders and insectary flowering plants such as marigold, Hibiscus, caraway, parsely, anise, cosmos, Alfalfa, coriander mustard and carrot etc. in the inner row also add to the diversity. 3-4 rows of such plants along the field border by arranging shorter plants towards main crop and taller plants towards the border act as natural barrier to immigrating pest population.
These plants can be used on internal bunds and as intercrops also. Due to enhancement of biodiversity by the flowering plants, numbers of parasitoids and predators (natural enemies) will also increase due to availability of nectar, pollen, fruits, insects, etc. Protect the major predators which are a wide variety of spiders, ladybird beetles, long horned grasshoppers, Chrysoperla, earwigs, etc. Also conserve parasitoids such as Trichogramma spp., Tetrastichus spp, Telenomus spp, Bracon spp and parasitic wasps etc.
Other important physical and ecological management strategies found effective in keeping the pest load below threshold level include:
1. Use disease free planting material, preferably tissue culture raised plants.
2. Do not adopt high planting density.
3. Adopt orchard sanitation, burn fallen twigs, leaves and fruits or put them in compost pits.
4. Open up the canopy frequently for better air circulation and light penetration.
5. Disinfect pruning tools with 1% sodium hypochlorite solution.
6. Setting up of yellow pan water trap/blue sticky traps 15 cm above the canopy for monitoring whitefly and blue sticky trap for thrips @ 1 trap/10 plants.
7. Setting up of 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).
8. Collect egg cards of beneficial insects such as Trichogramma, Chrysoperla, Telenomus etc from State Bio-control Labs.
9. Apply mycorrhiza and plant growth promoting rhizobacteria (PGPR).
10. Apply Trichoderma viride and Pseudomonas fluorescens as nursery treatment and soil application.
Keep on monitoring pest and defenders ratio. If pest: defender ratio is 2:1 then there is no need to worry, but if this ratio increases above 2:1 then adopt curative control measures.