Modern stone fruit varieties are propagated vegetatively to maintain desirable fruiting traits. Propagation by seed is not recommended because seed produced by cross-fertilization may yield undesirable trait combinations. Because seedlings grown from crosses between commercial fruiting varieties contain a mix of parental genetic backgrounds they will not be identical to either parent and will differ in growth and fruiting habit. This variability is desirable for plant breeding and development of new varieties, not for uniform growth in an orchard establishment. Seed used for seedling rootstock is generated by self-fertilization in a tree that is genetically homozygous, or by controlled cross-pollination between two parental varieties.
Peaches, and many other fruit and nut trees, have a low rooting percentage (Hartmann, Kester, Davies, & Geneve, 2002) because fruiting varieties tend to have a poor root system that is susceptible to pests, pathogens, or environmental stress. As a result, stone fruits are typically propagated using budding or cutting techniques and grown on rootstock varieties. Topworking, a form of grafting, is used to change the variety of fruit produced within an established orchard without replacing rootstock. California tree nurseries can propagate trees for sale in one year with June budding and two years with summer budding (Hartmann, Kester, Davies, & Geneve, 2002).
Tree nursery grower timeline for fruit and nut crops (Growing through the year with Burchell Nursery, 2011) http://www.burchellnursery.com/for-commercial-growers.php
Methods of Propagation
Propagation by seed (sexual propagation) is only used to produce seedling rootstock, or in breeding new fruit varieties.
Vegetative propagation (asexual propagation) produces exact genetic copies of plants via cloning. Several techniques are used to asexually propagate trees depending on the variety and time of year. Some forms of vegetative propagation are cheap and easy to execute (cuttings), others require special tools and highly skilled labor (budding and grafting), while some are very expensive and are conducted in laboratory settings by trained employees (tissue culture).
Although there are many methods of vegetative propagation only a few are ideal for commercial stone fruit propagation including by cuttings, topworking by grafting, and budding. For a discussion of these types of propagation, see the links at the top of this page. For further, detailed information, see the references (in above links)