Tree nurseries, grafting

Newly grafted fruit trees Fruit nurseries graft many hundreds of young trees each year, binding shoots of chosen cultivars onto the roots of other trees that will control height and vigor. The plant tissue fuses naturally at the graft point, or "union."... 

The parasites which cause plant diseases may be spread by wind, rain, insects, birds, snails, slugs, and earthworms, transplant soil, nursery grafts, vegetative propagation (especially in strawberries, potatoes, and many flowers and ornamentals), contaminated equipment and tools, infected seed stock, pollen, dust storms, irrigation water, and people. Figure 3.8 illustrates the effects of microbial infection of various fruit trees. 

Like most fruit trees, apples are not grown on their own roots. Instead, they are grafted onto the roots of compatible trees, usually other apples. Rootstocks help to control the eventual size of the tree. Depending on the rootstock selected, the same cultivar of apple might grow 8 ft (2.5 m) or 30 ft (9 m) tall. Ask the nursery for advice on heights and rootstocks. 

Commercial production of fruit trees and ornamental woody plants traditionally involved rootstocks grown from seed and buds or scions (grafts) from stock plants maintained by individual nurseries. Now both rootstocks and grafts are typically... 

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