endogenous plant pararetroviral sequence in its host, Dahlia variabilis Virology 376 253 257 Pahalawatta, V. Miglino, R. Druffel, K.L. Jodlowska, A. Van Schadewijk, A.R. Pappu, H.R. 2007
Sahar Eid, Keri L. Druffel, Dayle E. Saar, and Hanu R. Pappu
Brian E. Whipker and P. Allen Hammer
Plant growth retardant (PGR) substrate drench treatments (mg a.i./1.5-L pot) of ancymidol at doses of 0.5 to 8, paclobutrazol from 1 to 16, and uniconazole from 0.125 to 2 were applied to tuberous-rooted dahlias (Dahlia variabilis Willd.) to compare their effectiveness for controlling height. When the first inflorescence opened, the number of days from potting until flowering, leaf canopy height, inflorescence height above the foliage, and plant diameter were recorded. Total height control achieved using PGRs was primarily due to reduced inflorescence height, rather than leaf canopy height. Paclobutrazol, ancymidol, and uniconazole at all doses reduced total plant height of the less-vigorous `Red Pigmy' by >21% compared to the untreated control, with a height of 43.5 cm for the untreated control plants. Marketable potted plants were produced with doses of 2 to 4 mg of paclobutrazol, 0.25 to 0.5 mg of uniconazole, or 0.5 mg of ancymidol. All paclobutrazol, ancymidol, and uniconazole doses reduced total plant height of the more-vigorous `Golden Emblem' by >11% compared to the untreated control, with a height of 82.1 cm for the untreated control. Marketable potted plants were produced with 4 to 8 mg of paclobutrazol, 0.5 to 1 mg of uniconazole, or 2 mg of ancymidol.
Brian E. Whipker, Robert T. Eddy, and P. Allen Hammer
Shravan Dasoju, Michael R. Evans, and Brian E. Whipker
Paclobutrazol drench applications of 0, 2, and 4 mg a.i./pot were applied to `Pacino' potted sunflowers (Helianthus annuus L.) and `Red Pigmy' tuberous rooted dahlias (Dahlia variabilis Willd.) grown in substrates containing 50%, 60%, 70%, or 80% (by volume) sphagnum peat or coir, with the remainder being perlite, to study the efficacy of paclobutrazol (Bonzi). Potted sunflower plant height differed significantly for peat- and coir-based substrates, with greater plant height being observed in coir-based substrates. Plant diameter was significantly greater at higher percentages of peat or coir in the substrate at 2 and 4 mg of paclobutrazol. Inflorescence diameter also was significantly decreased as paclobutrazol concentration increased. When the percent of height control from the untreated plants for potted sunflower was compared between coir and peat-based substrates, the percent height reduction was similar for peat- and coir-based substrates at 2 mg of paclobutrazol and height control was greater at 4 mg of paclobutrazol in coir-based substrates. The differences in plant growth observed in peat- and coir-based substrates can be attributed to differences in physical properties of these substrates. Dahlia plant height, diameter, and number of days until anthesis were not influenced by substrate type or percentage. However, dahlia growth was significantly reduced as paclobutrazol concentration increased. Coir-based substrates did not reduce the activity of paclobutrazol drenches compared to peat-based substrates, although to compensate for the greater amount of plant growth in coir-based substrates, paclobutrazol concentrations may need to be increased slightly to achieve a similar plant height as with peat-based substrates.
Helen E. Hammond, Richard K. Schoellhorn, Sandra B. Wilson, and Jeffrey G. Norcini
, drenches are species and cultivar specific. Whipker et al. (1995) drenched potted ‘Red Pygmy’ and ‘Golden Emblem’ dahlia ( Dahlia variabilis ) with uniconazole and found that only ‘Red Pygmy’ responded enough to the treatment to be considered marketable
Nicholas J. Flax, Christopher J. Currey, James A. Schrader, David Grewell, and William R. Graves
ancymidol, chlormequat and daminozide on the growth and development of forced Dahlia variabilis Willd Scientia Hort. 4 123 130 Erwin, J.E. Henis, R.D. Karlsson, M.G. 1989 Thermomorphogenesis in Lilium longiflorum Amer. J. Bot. 76 47 52 Evans, M.R. Hensley
Daedre S. Craig and Erik S. Runkle
greenhouse environmental factors on forcing Dahlia variabilis Willd J. Amer. Soc. Hort. Sci. 102 314 317 Erwin, J.E. Warner, R.M. 2002 Determination of photoperiodic response group and effect of supplemental irradiance on flowering of several bedding plant
Neil O. Anderson and Richard T. Olsen
by pollinators or wind. As such, grow-outs required selection of off-types at the seedling or transplant stages, if possible. This practice is still in use with ornamental seed crops that are OP, e.g., Capsicum annuum , Dahlia variabilis