Water Jet – A procedure that uses high-pressure water and a probe to create air passages in the soil. Primary reason for use is mitigation for compacted soil. Water Jet can be used in conjunction with liquid fertilization only when soil and leaf tissue analysis indicate nutrient limitation.
Watersprout – Vigorous, upright shoot that arises from a latent or an adventitious bud above the ground or graft union on older wood.
Wetwood – Wood altered to a higher state of protection against mechanical disruption or decay by pathogens that make the wood so high in moisture, pH, and microelements that decay-causing pathogens are not able to infect. A disease of wood caused mostly by bacteria.
Wilting Point – That level of soil moisture at which wilted plants are able to recover following addition of water. Contrast with permanent wilting point.
Wound – An opening that is created when the tree’s protective bark covering is penetrated, cut, or removed, injuring or destroying tissue. Pruning a live branch creates a wound, even when the cut is properly made.
Woundwood – Differentiated woody tissue that forms after initial callus has formed around margins of a wound.
Wounds are closed primarily by woundwood.
Xylem – Tissue produced by the activity of the cambium and composed of tracheids, wood fibers, and parenchyma cells, which function to transport and store water and mineral elements as well as to provide mechanical support.