MULBERRY CULTIVATION (CONT...6) - PROPAGATION

Mulberry is propagated either through seeds or vegetative. The latter is the most common method of propagation because of various advantages like maintenance of particular characters of the plant, relative speed in raising saplings in large numbers for plantation, the adaptability to a particular habitat, to develop resistance to pests and diseases and to modify the growth of plant.

Seedling propagation: Propagation through seeds is mainly to bring about a varied population for the purpose of selection and hybridization.

Preparation of seedling nursery: An area preferably under shade is selected to raise seedling nursery in tropical countries. The soil is thoroughly prepared to a fine tilt.

Sowing of seeds: Seeds with viable embryos are soaked for a day in water to soften the hard tests for easy and successful geminating. They are broadcast in seed beds or sown in holes drilled in a line or sown in a line with the help of a rope.                                                                                                                                           

Germination of seeds: Temperature and light have a marked effect on the germination of seeds.

Seedlings: When the seedlings attain 3.5 to 5 cm height, they are thinned by picking from dense areas and planted in thinner areas. Direct sunlight which is essential for young plants is allowed to fall on them during the cool hours of the day and on cloudy days.

Cutting: It is restricted to varieties which are fully acclimatized to local condition.

Preparation of the cutting: Shoots of proper maturity and thickness with active and well developed buds are cut from the selected varieties.

Formation of roots: Adventitious roots develop from the basal end of the cutting as also from the root anlagen of the bud. The roots develop endogenously.

Artificial induction of rooting with growth regulators: Those varieties which do not ordinarily produce roots from a cutting are induced to‑root with the application of requisite quantity of root hormones. The following are the chemicals generally used: however, the efficacy of the substances varies from species to species and from variety to variety:

1.     Indole Acetic Acid;

2.     Indole Butyric Acid;

3.     L. Naphthalene Acetic Acid;

4.     2,4 Dichlorophenoxy Acetic Acid;

5.     2,4 Dichlorophenoxy Butyric Acid;

6.     2,4,5 Trichlorophenoxy Butyric Acid;

7.     2,4,5 Trichlorophenoxy Propionic Acid;

8.     2,4,5 Trichlorophenoxy Butyric Acid;

       And various other commercial products like rootone, seradix, etc.

Methods of application of root hormones to cuttings: The object of treatment is to increases the percentage of cuttings which form roots, hasten the root initiation and increase the number of roots per cutting.

Direct application of the chemical: These regulators are commercially available in the form of powder mixed with talc. Mixtures in different concentrations are spread on thin aluminum foil or wax paper.

Soaking the cuttings in dilute solutions: Aqueous solutions of the chemical in different concentrations are prepared.

Dipping the cutting in concentrated solutions: A concentrated solution of the chemical is prepared in alcohol and the basal portions of the cuttings are dipped for a shorter duration and planted immediately in the rooting medium.

Duration of treatment: Duration of treatment has a considerable effect on the root formation in lower and higher concentrations.

Application as lanolin paste: Requisite growth regulator mixed with lanolin base and smeared round the basal portion of the cutting also induces rooting.

Grafting: Grafting consists of inserting a small branch of a plant into a rooted plant of the same or allied species in such a way as to bring about an organic union between the two and finally make them grow as one.

Anatomy of graft union: When the scion is inserted into the stock, organic union is established between them by the formation of secondary vascular tissues. Hence the cambium layers of the stock and scion are brought in close contact with each other.

Wedge Grafting: Wedge grafting is followed to renovate the old plant. The plant s pruned at a height of convenient level and incision is made at a cut surface in the form of letter "V". The basal end of the scion is also cut obliquely downward to fit in the in cession made on the stock. The scion is inserted into the stock and the grafting wax or grafting clay is applied at the region of contact.

Grafting wax: A mixture of tallow part, bees wax one part and resin four parts, melted together and baked with small dough under water.

Grafting clay: Clay two parts, cow dung one part and some finely chopped hay mixed with after.

Crown grafting: When more than one scion is inserted, it is called crown grafting.

Whip grafting: To a stock of about 1.2 to 2.5 cm thickness, sloping cut is given to a length of 3.5 to 3 cm.

Root grafting:  When the root is used as a stock instead of shoot the grafting is called root grafting. Mysore Local variety is used as a stock material.

"In Situ" grafting: In this type of grafting, the seedling which is used as stock is cut below the ground level including the transitional level and the grafting is done as in the case of root grafts but without disturbing the root from its original place in the soil.

Bud grafting (Budding): This method is followed only when the scion material is scarce. Bud grafting involves removal of only one bud and a small section of the bark without wood and grafting it to another clone.

Patch budding: A portion of the bark with an active bud is removed from the bark as scion.

T‑budding: A “T" shaped incision is made on the bark of the stock at the nodal region and a slit is formed by opening the cut ends. A bud cut out clean from the selected plant is inserted in this slit and properly bandaged.

Flute budding:  The bark of the plant is cut to a length of 2 1/2 to 3 3/4 cm round and removed as a sheath. Similarly, the bud of the scion with the same length of the bark is removed and inserted in the stock from where the bark is removed and bandaged properly.

Layering: Layering is another type of propagating mulberry. It is the development of roots on a stem while it is still attached to the parent plant.

Air layering or gooting: In this method, 1.2 cm circular bark is removed from the stem, where peat mass or well decomposed organic manure with a little quantity of root promoting hormones is placed at the region and tied securely with a polyethylene cover.

Trench layering: It consists of growing a plant or a branch of a plan in a horizontal position in the base of a trench and filling in the soil and manure around the new shoots as they develop.