Everything you need to learn about cultivating plum organically. Learn about:- 1. Introduction to Plum 2. Climate and Soil Required for Plum Cultivation 3. Propagation and Rootstocks 4. Planting and Spacing 5. Training, Pruning and Canopy Management 6. Weed Control and Mulching 7. Harvesting 8. Varieties.
Contents:
- Introduction to Plum
- Climate and Soil Required for Plum Cultivation
- Propagation and Rootstocks of Plum
- Planting and Spacing of Plum
- Training, Pruning and Canopy Management of Plum
- Weed Control and Mulching of Plum
- Harvesting of Plum
- Varieties of Plum
1. Introduction to Plum:
Plum (Prunus salicina) is an important temperate fruit of the country and it ranks next only to peach. Plums are rich in sugars and vitamin-A. Plums are used both as fresh table fruit and also used extensively in making jams. Two types of plums are generally cultivated in India.
European plum (P. domestica) is cultivated at higher elevations and the Japanese plum (P.salicina) at lower elevations and in the sub-mountain area. Plum is grown in H.P, J&K, Punjab and hills of U.P and Nilgiri hills of south India. Plums are cultivated in an area of 23, 940 hectares with a total production of around 74,120 tons (2012-13). Data for exact area and production in different states is not available.
2. Climate and Soil Required for Plum Cultivation:
Plums can be successfully grown from subtropical plains to the temperate high hills. European plum performs best at 1300-2000m above mean sea level. It requires about 1000-1200 hr of chilling below 7°C to break rest period, whereas, Japanese plums require 700-1000 chilling hours and thrive best at an elevation of 1000-1600m above mean sea level.
The area with frost free spring, having good drainage and adequate sunshine are ideal for plum cultivation. Plum requires 900-1100 mm well distributed rainfall throughout the year for good growth and fruit development. Deep, fertile and well drained, loamy soils having a pH of 5.5 to 6.5 are most suitable.
3. Propagation and Rootstocks of Plum:
Grafting and budding are commonly used for the commercial multiplication of nursery plants. Plum is raised on seedling rootstocks of wild apricot and Myroblan B plum clonal rootstock. In Punjab, Kala Amritsari variety is propagated through hard wood cuttings.
Raising Wild Apricot Seedlings as Rootstocks:
Seeds of Zardalu wild apricot are collected from fully ripe fruits. After drying the seeds, these are treated with 5-10 g each of Trichoderma viride and Pseudomonas fluorescens per kg of seeds and stored at 3.5 to 7.5°C and 20% RH.
For breaking dormancy seeds are stratified in 30-45 cm deep pits located in cool and dry place during January month. Stratified seeds are sown in nursery beds 6-10 cm deep, 10-15 cm between seeds and in 25-30 cm wide rows. In a year most of the seedlings become graftable.
Raising of Clonal Rootstock Myrobalan B:
Myrobalan B rootstock is multiplied through stooling. Rooted layers of clone are planted in stool beds in December month at a distance of 30 cm in rows and with spacing of 60 cm between rows. Rooted layers are separated in December and planted in nursery beds for further grafting.
Both wild apricot seedlings and Myrobalan B are grafted in February when they attain 0.8 to 1.2 cm thickness, using disease free scion collected from plants having known pedigree. Tongue grafting or chip budding is done in February month.
4. Planting and Spacing of Plum:
In flat and valley areas, it is planted in square system, whereas in slopy land it is planted in contour or terrace system. As usual 1m x 1m x 1m pits are dug and 20 to 25 kg F.Y.M is mixed in top soil along with 50 g each of Trichoderma viride and Pseudomonas fluorescens. Planting is done during December-January. Graft union should be kept 15-20cm above the ground level while planting to avoid collar rot.
A spacing of 6m x 6m is usually recommended for all the plum varieties. High density planting, having spacing of 3m x 3m is not a preferred approach under organic management. For organic cultivation 6m x 6m or 6m x 8m spacing can be adopted to accommodate cover/intercrops for creating diversity for containing pests and for soil moisture conservation and soil enrichment.
5. Training, Pruning and Canopy Management of Plum:
Plum plants are mostly trained on modified leader or open centre system. Training is done to give proper shape and strong frame work to the plant. Only wide-angled branches should be selected and remaining branches are pinched off. Lowest scaffolds branches should be about 30cm above the ground level and the other scaffolds should be 15 cm apart in spiral order. Pruning during prehearing period is usually kept light and corrective.
But later when plants have grown up, light heading back and removal of water sprouts, dead, diseased and criss-crossing branches is usually done. Plum generally bears on spurs but some fruits are produced laterally on one year old shoots. The lifespan of plum spurs is 5-6 years. Pruning is necessary for spur renewal and 75-80% removal of new growth in each season, which is done usually in January.
Irrigation:
Generally plums are grown on slopy lands under rainfed conditions. Under such conditions there is always soil moisture deficiency during fruit growth and development period. The maximum water requirement is during May- June months. Irrigation at 50% of field capacity at 9-12 days interval is very necessary for good yield and quality fruits. About 6 irrigations are required in a season for plum orchard in mid-hills.
6. Weed Control and Mulching of Plum:
Clean basins and permanent sod is usually practiced in mid hills for plum cultivation. Basins need to be kept clean by hand weeding or applying mulches. Application of 10-15 cm thick layer of biomass is needed for mulching of basins in March. It is also useful in conserving moisture.
7. Harvesting of Plum:
Plum is a climacteric fruit, and as such does not ripe fully on the mother tree therefore; it should be picked at a proper stage. Various maturity indices like days from full bloom, firmness, TSS, change of fruit colour are used to judge proper maturity of plums. Generally 2 pickings are recommended for plums, since all the fruits do not mature evenly on trees, at one stage. Fruits are picked without pedicels in such a way that bruising and stem punctures are avoided.
After picking they are put softly in picking baskets lined with gunny cloth and transported to grading and packing house. Fully grown plum tree yields 60-70kg fruits. Plums are graded according to their fruit size in 3 grades. Fruits are packed in layers in wooden boxes of 37 cm x 16.5 cm size or card board boxes of 5 kg capacity. Plums can also be stored for 2-4 weeks at 0°C with 85-90% relative humidity.
8. Varieties of Plum:
Most promising plum varieties suitable for cultivation at different elevations, seasons and for different states are:
Jammu and Kashmir:
Early season – Saharanpuri White, Plum First Ramgarh, Maynard Sharps, Early Subza
Mid-season – Formosa, Maynard, Bryanstones Gaze, Burbank, Santa Rosa
Late season – Satsuma, Grand Duke, Silver Wickson, Beauty, Cloth of Gold, Golden Gage
Himachal Pradesh:
Early season – For high hills – Sweet Early, Methley, Kelsey, for mid hills – Santa Rosa, Beauty, Early Red Beauty, Transparent Cage and for low hills – Alucha Purple & Titron.
Mid-season – Starking Delicious, Satsuma, Burbank, Frontier, Kanto-5.
Late season – Mariposa
Uttarakhand:
Early season – Jamuni, Titron, Settler, Cloth of Gold, Ramgarh Maynard
Mid-season – Howe, Alubukhara Sharbati, Zardalu, Zardalu Chittidar,Burbank,
Elephant Heart, Satsuma, Black Chamba, Victoria
Late season-Late Yellow, Kanto 5, Sweet Early, Santa Rosa, and Mariposa
Punjab:
Early season – Satluj Purple
Mid-season – Titron, Kala Amritsari, Kataru Chak
Late season – Alubukhara