Cc. Pasian, Response of Dendranthema grandiflora (Ramat) to three plant growth regulators in container paint mix applications, SCI HORT A, 80(3-4), 1999, pp. 277-287
The effectiveness of plant growth regulators (PGRs) when applied in a paint
mix to the inside of containers was evaluated. Two kinds of paint (regular
flat latex and SpinOut(R) were evaluated for their respective effectivenes
s with three separate plant growth regulators (paclobutrazol, uniconazole,
and ancymidol) on the growth of Dendranthema grandiflora (Ramat) (cv. Fina
and Pelee) plants. Chrysanthemums grown in containers were subjected to thr
ee different application methods: interior surfaces covered by a mixture of
paint and plant growth regulator (PGR) and soil drench or spray treatments
according to label recommendations. The effect of composted pine bark on t
he effectiveness of two methods of application (paint and drench) was also
compared. Paint alone had no effect on growth and development. None of the
plants given treatments with paint with or without PGR, showed any sign of
phytotoxicity. Plants exposed to PGRs appeared greener and were shorter tha
n control plants. Both the regular flat latex and SpinOut paints were effec
tive carriers of PGRs, although plants grown in containers coated with PGR/
SpinOut paint were taller than plants grown with latex/PGR-coated container
s. Composted pine bark slightly reduced the effectiveness of ancymidol on p
lant growth. This reduction in effectiveness was smaller when ancymidol was
carried by latex paint but was greater when carried by SpinOut paint. Thes
e results indicate that the paint/PGR method may not represent any real adv
antage over the drench method to overcome the effect of composted pine bark
in the growing mixes on the effectiveness of ancymidol. Chemical names use
d: beta-((4-chlorophenyl)methyl)-alpha-(1,l-dimethazole-l-ethaol (paclobutr
azol); (E)-(+)-(S)-1-(4-chlorophenyl)-4,4-dimeth l-yl)-pent-1-ene-3ol (unic
onazole-P); alpha-cyclopropyl-(p-methoxyphenyl)-5 pyrimidinemethanol (ancym
idol). (C) 1999 Elsevier Science B.V. All rights reserved.