ฉันรักแปลAuxins as root-promoting chemicals (often commonly referred to as “rooting hormones”)
are most frequently applied to stem cuttings using a basal quick-dip in
a concentrated solution, a powder (talc) application, or an extended basal soak in
a dilute solution. Liquid formulations offer the advantages of fl exibility by allowing
dilutions to various fi nal concentrations and uniform application to the base of
the cuttings, while powder formulations require no additional preparation prior to
use. Registered products in the United States include IBA (indolebutyric acid) and
IBA/NAA (indolebutyric acid / naphthaleneacetic acid) combinations in the form of
liquid concentrates, water-soluble tablets, and powders.
The basal quick-dip is the most popular method of auxin application in nursery
propagation. Historically, commercial propagators have found quick-dips to be
the quickest and most economical method as a limited amount of material can be
applied directly to the basal region of the cuttings where adventitious root initiation
and development will take place. The concentration of the auxin formulation
can be modifi ed to produce optimal rooting of the cuttings. Powders are the next
most common method of applying auxins, but propagators are limited to certain
concentrations. Some propagators may subject cuttings to an extended basal soak,
which typically requires the bundling of cuttings along with additional time and
space for the treatment process. Other methods of auxin application that have been
investigated include forced entry of auxins into cuttings using a vacuum, insertion
of auxin-treated objects (such as toothpicks) into the cutting base, immersion of cuttings
in an auxin solution for varying lengths of time, and treatment with auxins in
a lanolin base (Blazich, 1988). Some of these uncommon methods remain of interest
in the history of cutting propagation, while others still fi nd use under certain
circumstances with specifi c crops.
One method of auxin application that has received limited investigation is a
foliar spray application, although many other liquid plant growth regulators and
pesticides are applied as a spray under production conditions. Another method that
has not been investigated is application of auxin to stem cuttings via the rooting
substrate (medium). Substrate containing auxin is used in other methods of propagation,
particularly tissue culture.