I’m looking for the definition of the term “bark slip” and the time of year when bark slip is most likely to happen. For example: “T-budding, the most popular budding method, is limited to the time of the year when the bark is slipping, however, chip budding can be used when the bark is not slipping.”
The term “bark slipping” is being used in the context of grafting.
According to Texas A & M University’s Horticulture department, bark slipping happens when the rootstock of a tree is in active growth.
Excerpt:
“Successful T budding requires that the scion material have fully-formed, mature, dormant buds, and that the rootstock be in a condition of active growth such that the ‘bark is slipping.’ This means that the vascular cambium is actively growing, and the bark can be peeled easily from the stock piece with little damage. T budding can be performed on certain fruit trees (peaches, for example) in June using cold stored budsticks and field grown seedling rootstocks. Many deciduous trees are budded in late July or early August after the current seasons buds have developed fully and are dormant using field grown seedlings that have slipping bark.”
Similar information from North Carolina State University Extension indicates that the time when bark is slipping varies, depending upon the type of tree, and upon weather conditions.
Excerpt:
“T-budding must be done when the bark will ‘slip.’ Slipping means that, when cut, the bark easily lifts or peels in one uniform layer from the underlying wood without tearing. The exact time when this condition occurs depends on soil moisture, temperature, and time of year. It varies with species and variety. Dry or excessively hot or cold weather can shorten the period when bark slips. Irrigation can be valuable in extending the T-budding season.”
In The Grafter’s Handbook by R. J. Garner (Cassell, 1988), bark is referred to as rind, but the principle is the same:
“Budding is done when the rinds readily part from the wood of the stock and when buds have developed at the base of the leaf-stalk on young shoots of the scion variety. This means that the budding season may extend from early June until September, but from the end of June until mid-August is the optimum time in normal seasons. In periods of prolonged drought the rind may not lift without tearing, and it is then wise to postpone budding in the hope that rain will come and rootstocks increase their rate of growth.”