Temprate Fruits (1+1)

ROOTSTOCKS AND PROPAGATION

Rootstocks and propagation

• Seedling rootstocks: The plum grown mostly on plum rootstocks though seedling of peach, apricot and almond can be used. In India plum is propagated mainly on seedlings of wild apricot (Chuli)
• Clonal Rootstocks for plum: Myrobalan B, Myrobalan 29C, Mariana GF 8/1, Mariana 2624, Mariana 8-6. Mariana 9-25, Pixy, St. Julien A, GF-667

Propagation

Rootstock :

• Plums are propagated vegetatively by budding and grafting on rootstocks.
• These can also be propagated by hard wood cutting and by leafy soft wood cuttings under intermittent misting. Cuttings taken from hard wood and semi hard wood treated with IBA (2000-5000ppm) for better rooting..
• For raising the seedlings, the seeds of wild apricot are stratified under alternate layers of moist sand for 45 to 50 days at temp 3-5°C to break the rest.
• The stratified seeds are sown in nursery beds 6-10 cm deep in row 25-30cm apart with a distance of 10-15 cm from seed to seed.
• The seedling attain graftable size in a year
• In Punjab, own rooted plants of Kala Amritsari are generally used for planting.
• Clonal rootstocks of plum are multiplied commercially by layering.
• It has been observed that most of clonal rootstocks of plum are difficult to root. Application of 2500ppm IBA to stool shoot helps to improve rooting.
• Clonal rootstocks are also propagated by hardwood cuttings. The hardwood cutting should be taken during dormant season and dipped in 2500ppm IBA solution for 30 seconds. Then these cutting are planted in mist propagation chamber for rooting.

Propagation of scion

• Seedling as well as clonal rootstocks which are 0.8 to 1.2 cm in thickness are grafted in February with tongue and cleft method of grafting.
• The seedling which do not attain graftable size in February, they should be budded with T- and chip methods of budding in June- July.
• For grafting the scion wood should be collected from healthy, disease free, true to variety trees during January . The scion wood is collected from one year old shoots. They are packed in moist sphagnum moss, which are properly labeled for variety. These bundles of scion wood are stored in cold storage or buried deep in the soil at shady place till grafting is done.
• The best time of grafting of these fruits are February in lower elevation and in March at higher elevations.
• Chip budding can also be done in March, July and September..

PLANTING AND PLANTING DENSITY

• Planting of plum is done December -January when the plant is in dormant conditions.
• Before planting, site of an orchard should be properly cleared off the bushes and weeds. It is advisable to plough the plantation area.
• In hilly area, terraces should be kept inwards to facilitate soil conservation.
• The orchard area should be properly laid out about two month before planting. In sloppy land, layout of an orchard should be done with contour or terrace system , while in flat land square system is followed.
• The planting distance varies according to the varieties, rootstocks and fertility of soils. Plums are generally planted at a distance of 6 m x 6 m.
• In high density plantation , the plum plants raised on semi-dwarfing clonal rootstocks should be planted at 4m x4m distance.
• Pits of 1 m x1 m x 1 m size are dug in October – November . Pits should be filled with fertile top soils mixed with 40 kg of well rotten FYM and 1kg of single super Phosphate.
• To avoid any damage from insects, the pits are drenched with 10 litres of chlorpyriphos (4ml/L)solution. The graft union should be kept 10-15 cm above the ground level at the time of planting to avoid any scion rooting.
• Young plants should be watered regularly and basin area is mulched with 15 cm thick dry grass.

Pollination and Fruit Set

• Most native American plums are self unfruitful and need pollinizers be inter planted in the orchard. The partial self fruitful cultivars such as Santa Rosa and Beauty are also benefited in fruit set with the pollinizers.
• The European plum in view of the fruit set are categorized in to self fruitful varieties in which 30% of the flowers set fruit and self unfruitful varieties in which 1.5 to 2% of the flowers set fruits which need pollinizer.
• For proper pollination and to obtain good harvest, at least every third tree in every third row, a pollinizer should be planted with the strong beehives per acre.
• In case, the cultivars produce little or no pollen, a pollinizer branch should be grafted on every tree.