Methods of Improving Tree Crops Quality (Increasing of Branching) in the Orchards' Nursery

The quality of plant stocks in the nursery has proven to be a key determinant factor in precocity of fruit bearing period and the size of tree crops. The quality of these trees is related to growth strength of the applied rootstock, the tendency of the cultivars to produce branches, the growth season's weather conditions as well as the efficiency of different treatments stimulating branching and the time of the growth of young shoots. The number of lateral branches provides the opportunity to obtain good tree architecture in the future. Moreover the height, location and the wide angle of laterals grantee earliness and higher yields. Larger caliper trees grow more and produce higher yield in 4-5 years as compared to the smaller caliper trees. Due to strong apical dominance, many economically important cultivars produce few lateral shoots in nursery by nature. The tip-pruning techniques can reduce apical dominance and hence induction of buds that might remain dormant. The techniques might not have been always resulted in satisfactory outcomes for an increase to branching because of induction of low numbers of lateral shoots and branch erectness thus, application of bioregulators may consider being necessary. Cytokinins such as benzyladenine (BA) alone, or in combination with gibberellins are of these bioregulators used to overcome apical dominance and to induce branching in nurseries and in young orchards. Also the application method and concentration of the chemicals are thought to be important for obtaining the desired physiological effect in various fruit trees. Regular application of plant growth hormones could increase the number of laterals that is reported for apples and cherry. In this article, considering the importance of improving the tree crops' quality, emphasis was put on studying the methods of inducing of lateral shoots in the orchards' nursery.