STEM BANDING ENHANCES ROOTING OF APPLE ROOTSTOCK CUTTINGS
By Pat Holloway
“Softwood shoots of M.9 and MM. 106 were banded with Velcro for up to 20 days before cuttings were propagated. Banding 10-20 days increased percent rooting and number of roots/cutting and the longer the banding the greater the effect. In M.9, banding resulted in a higher survival rate and increased new shoot growth of transplanted cuttings. Percent budbreak and new shoot growth were highly correlated with the number of roots per cutting of both rootstocks. From Sun and Bassak.
HortScience
26:1368-1370.”
NOTE: I have received several inquiries about vegetative propagation of apples. Many apples are difficult to root from cuttings. Timing of cutting collection is very important. The above excerpt identifies one method that has been used to help improve rooting success and promote growth on rooted cuttings.
Banding is the process of excluding light from the base of the cutting while it is still attached to the mother plant. Choose young, actively growing shoot tips (softwood cuttings), and about 6” from the tip, wrap the stem with some type of light-excluding material. Originally, people used tape, especially electricians’ tape, but tape is sticky and messy. More recently, people have been using strips of Yelcro (2-4” wide) that are wrapped around the stem. Whatever is used the purpose is to exclude light.
The reason you want to exclude light is to build up concentrations of a hormone auxin, in the plant tissues. Auxins are the most important hormones involved in rooting and therefore, high concentrations should produce greater rooting percentages. Auxins are destroyed by light so if you can exclude light you increase the level of auxins in the plant. The article quoted above recommends covering the base of the shoot up to 20 days before the cutting is made. The shoot continues to grow on the plant and auxins build up beneath the Velcro. Cuttings are made by snapping off the shoot just below the Velcro and rooting them like you would any other softwood cutting.
This practice is certainly not new; the use of Velcro is a similar practice has been used for years to get stem cuttings of difficult- to-root plants, such as lilacs, to produce roots. Etiolation is a more elaborate method used to exclude light from the entire cutting. Entire branches or plants are cut back in spring to encourage shoot growth. A black bag encloses the entire branch or plant, and shoots grow in complete darkness. The resulting shoots are long, spindly, and usually a whitish-yellow color. These shoots are snapped off and rooted as normal softwood cuttings. They are very tender and susceptible to sunburn, but if handled properly, rooting successes can be high. Both methods are worth trying if you want to root your own apple or crabapple cuttings.