Propagation of fruit trees is sexual and asexual. In the method of sexual propagation, the seeds of fruit trees are used. One of the advantages of propagation by seeds is that this method is economical, seed storage, easy transportation and non-transmission of viral diseases, but one of the disadvantages of seed propagation, especially in fruit trees, is the seed impurity (Heterozygote) and the resulting trees are produced. , Are not like the mother base.
Propagation of fruit trees is sexual and asexual. In the method of sexual propagation, the seeds of fruit trees are used. One of the advantages of propagation by seeds is that this method is economical, seed storage, easy transportation and non-transmission of viral diseases, but one of the disadvantages of seed propagation, especially in fruit trees, is the seed impurity (Heterozygote) and the resulting trees are produced. , Are not like the mother base.
Apart from the natural selection of the plant, the impurity of the seeds is also due to Pollination _ Cross metamorphosis.
In the asexual or vegetative method, due to the use of somatic cells, the plants produced are completely similar to the mother base, and a group of plants that are produced asexually from a mother base is referred to as a clone.
In general, asexual methods of plant propagation include dormancy of branches, cuttings, transplantation and use of cuttings.
Sleeping branches
One of the most common methods of propagating the bases of fruit trees is the method of dormant heaps. During the growing season, the buds awaken and produce new shoots. Gradually, as the new shoots grow, soil is applied to the plants at one or two turns so that the height of the mound is 20 cm. In the early spring of the second year, the soil of the bushes is removed and the rooted branches are cut from the bottom of the roots and transferred to the treasury. They are called grafted and the transplanted seedlings are ready to be transferred to the main land.
With the method of dormant dormancy, the rootstocks of hard-rooted fruit trees can be propagated, including the rootstocks of Maling, Maling Merton, and cherries (colt, f12 / 1).
Another method is asexual propagation of fruit tree stems by softwood, semi-woody and woody cuttings.
Cuttings of fruit trees in terms of rooting include easy rooting cuttings and hard rooting cuttings.
Easy rooting cuttings take root easily and there is no problem in their rooting. These types of cuttings contain effective factors in rooting such as rooting agents and natural auxin. Auxiliary rooting agents such as catechol, chlorogenic acid, oxidized terpenoids and phenolic compounds are known as auxin cooperative compounds or rooting coagulants.
Hard-rooted cuttings that do not have auxiliary rooting agents. For this purpose, synthetic auxin derivatives such as IAA, IBA, NAA are used before planting. The type of wood selected has a significant effect on rooting of cuttings. Soft-rooted and semi-woody cuttings are prepared from hard-rooted trees in mid-or late spring, but woody cuttings can be prepared from easy-rooted fruit trees during the plant dormancy period. In addition, hard-rooted trees are used to prepare cuttings from vegetative branches that lack flowers and fruits, because cuttings that contain reproductive organs contain root-blocking substances. The bottom of the branch is the most suitable part for preparing cuttings because it contains enough carbohydrates and has more rooting capacity. Cuttings prepared from branches near the crown that are close to the root of the plant have more rooting than the upper branches of the mother plant because it is non-rooted near the crown and in addition to the stimulus of ectopic root originating from the root of the plant increases the root Giving is cuttings.
Transplantation is one of the asexual propagation methods of fruit trees, which by connecting two pieces of living plant tissue, leads to the formation of an independent plant. It forms part of the trunk and crown of the tree called the scion.
Causes of grafting in fruit trees
- Propagation of clones whose sexual multiplication causes differentiation of traits, ie the seeds of this type of fruit trees produce in case of reproduction of plants that do not look like the mother base.
- Reproduction of clones that cannot be propagated by other methods of asexual propagation, such as cuttings.
- Propagation of modified clones of fruit trees so as not to change their traits
- Early fruiting of fruit trees
- Utilizing the basic benefits of fruit trees in different climatic conditions and different soil conditions and other purposes such as shortening fruit trees
One of the important points in observing the grafting action is the hammering of the base and scion cambium layers, because the first communication between the base and the scion is done by connecting their cambium.
The physiological conditions of the base and the scion are ready during the transplant operation. For this purpose, the branch transplant is usually done in areas that do not have cold winters in September and in areas with cold and icy winters from mid-March to May. The best time for bud transplantation is mid-June.
Closing the wound site after transplantation is necessary. In bud transplants, thread or grafting tape is used to close the wound, and in branch transplants, the left side of the graft is used. Observance of polarization is essential in grafting, and for this purpose the part close to the crown of the scion is connected to the far end of the base crown.
Types of grafts on fruit trees
From bud transplants, which include a part of the bark and buds of an annual branch, it is attached to the 1 to 3-year-old base by various methods, including abdominal, patch, tube, and scion grafts, but the usual method of bud transplantation in fruit trees is grafted. It is an abdomen that is used in nurseries for transplantation on the bases of seeds and clones. The bases used are one-year or multi-year.
