ARTIFICIAL METHODS Human have taken advantage of this natural phenomenon and have artificially propagated plants vegetatively by using the specialized parts as described earlier or by cutting, grafting and layering. When we use the vegetative parts for propagating crops or ornamental plants it is termed as artificial vegetative propagation.
(a) Cutting: Many plants like rose, Bougainvillea, croton, coleus, money plants, sugarcane etc. are grown through their stem cutting. Cuttings of these plants can be grown even in water where they strike roots and develop adventitious buds.
(b) Layering: In this method, a lower branch of a plant is bend down and covered with moist soil leaving the growing tip above the soil. A ring of bark is removed from the stem before it is bent down. In a few weeks time when enough roots have developed on the underground portion above the ringed part, it is cut off from the parent plant and grown separately as an independent plant. Example: Jasmine, Straw berry, grapevine, Bougainvillea etc.
Citrus, Mango Orchids, Chrysan themum, Asparagus.
(c) Aerial layering or Goatee is a similar practice where bending of branches isn’t possible because of the height of plant or due to woody nature of stem. In this method a ring of bark is removed from a selected branch and it is covered with moist moss and enclosed in a polythene sheet when roots appear, the stem is cut below the roots and planted to form a new plant.
(d) Grafting: It is especially important for propagation of seedless varieties of plants. It consists of inserting a small branch into a rooted plant. The rooted plant taken as a stock is resistant to disease and is physically sturdy. In this stock a branch is inserted which is known as scion or graft. This scion or graft is the stem cutting from the desired plant. Usually, the grafted end of stock and scion fit well with tape or rubber-band until their tissues unite and vascular continuity is established. Grafting is mostly practised in dicot Plants. Grafting has been found extremely useful in propagating improved varieties of various flowers and fruits like rose, Bougainvillea, Citrus, mango, apple etc.
The lower part of the stem of scion is cut in a wedge. (b) The shoot of the plant to be used as a stock is cut off. The stem is slit vertically the scion is inserted into the stock and is tied with a tape (c) the graft union occurs within a short time.
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