In order to obtain generative rootstocks in horticulture, i.e.. from seeds, in the spring, seeds of fruit trees are sown in rows distant from each other in a properly prepared field 30-40 cm, and in a row what 3-4 cm. However, it should be remembered, that the seeds of fruit trees are not able to germinate immediately after harvesting, because they contain biologically active substances in their tissues that inhibit their germination. That's why, so that the seeds can germinate, there must be a transformation of these substances in them, called inhibitors, in growth stimulants stimulating germination of the embryo. This transformation, called post-maturation, only occurs at low temperature (from 0 do 8°C), with high air humidity and oxygen access. Procedure, to whom we subject the seeds, that they undergo a post-maturation process, we call stratification. It consists in mixing the seeds with moist sand, with sawdust or very fine peat and store them indoors, in which the air temperature will be 4 ° C for several months. It is now recommended to soak the seeds in water prior to stratification: pome tree seeds by 3-4 hours, stone tree seeds – by 1 day.
The length of the post-ripening period depends on the species and variety, the course of tree growth in the period of seed and fruit formation, as well as the stratification conditions. And here is the after-maturation time for specific tree varieties: Antonówka ordinary -60-90 days, Caucasian pear – 70-90 days. Grusza Polna – 70-90 days. Bird cherry – 110-140 days, Antypka – 90-120 days, Alych -110-150 days, peach – 90-120 days, morela – 90-120 days and walnut – 70-100 days.
The seeds of the pome trees are sown in the spring, stone tree seeds can be sown either in the fall or early spring. The appearance of the first sprouts in stratified seeds is a signal for the immediate sowing of seeds. If you are interested in producing your own rootstocks and trees, please refer to the book by Alojzy Faktczyk. [4].
In order to regulate the nursery production, which includes fruit trees and shrubs, was released on 29 May 1957 r. special nursery law (Dz. U. nr 31 with 11 June 1957 r.). It defined the conditions and production standards, which are to provide the recipient with the most valuable planting material. Production in nurseries is controlled, and only certified nursery material may be marketed, i.e.. conforming to the standards. The Executive Ordinance of the Minister of Agriculture issued on the basis of this act of 3 of August 1957 r. (Dz. U. nr 45 with 1957 r.) established on the production and sale of fruit trees, bushes and rootstocks, in which farms the nursery can be run, the area it can occupy, determined the qualifications of the head of the nursery, the way it is conducted, qualifying (quality control). Moreover, the act regulates the methods of selling nursery material. The production of the washers was also specified, the keeping of fruit trees on their own trunks and on the leading one, quality standards of fruit trees and shrubs, purity of the variety, requirements for the health of nursery material and the selection of fruit tree varieties recommended for cultivation was specified, which is updated from time to time. In this way, all issues related to the production of planting material were regulated, which will be discussed in the chapters related to the cultivation of fruit and ornamental plants.