Kathy has a good theory that it may have been caused by auxin toxicity.
Auxin is required for root initiation but inhibits root elongation.
Page 281 of The Biology of Horticulture by Preece and Read (Wiley, 1993).
has a photo. Thus, how rooting was evaluated - root number or total
root length - could affect the interpretation.
Did you use Mung bean? The mung bean rooting bioassay may respond to many
other factors besides auxin concentration so it can be tricky. A detailed
description of the experimental methods may reveal an explanation for the
unexpected results.
Plant Propagation Principles and Practices by Hartmann and Kester
(Prentice Hall, 1983) has an extensive discussion of factors affecting
adventitious rooting of cuttings.
David Hershey
Prince George's Community College
Largo, MD
email dh321 at PGSTUMAIL.PG.CC.MD.US
