PLANT GROWTH REGULATOR EFFECTS ON HEIGHT AND LANDSCAPE PERFORMANCE OF PERENNIAL BEDDING PLANTS

Containerized production of perennial bedding plants is hampered by their vigorous growth rates and the lack of knowledge of their response to chemical plant growth regulators.
Six perennial bedding plant species were treated with foliar applications of 5000 ppm B-Nine WSG (every 2 weeks), a tank mix of 5000 ppm B-Nine WSG and 1500 ppm Cycocel, or Sumagic at 0, 15, 30, 45, or 60 ppm.
Vegetative plant height was measured at 3 and 5 weeks after treatment (WAT), after which plants were planted in raised landscape beds to evaluate subsequent growth and quality.
Five of the six species were responsive to B-Nine, while the tank mix effectively reduced the height of four species (Salvia greggii, Heliotropium arborescens ‘Fragrant Blue’, Gaillardia grandiflora ‘Burgundy’ at 3 WAT only, and Perovskia atriplicifolia). These responses did not persist in the landscape.
Four species, S. greggii, Salvia leucantha, Gaura lindeheimeri ‘Whirling Butterflies’ and P. atriplicifolia) were excessively affected by 60 ppm Sumagic, with 45% height reductions.
Carryover effects of Sumagic on plant height and performance in the landscape were observed at 4 weeks after planting (WAP) in S. greggii, G. lindeheimeri, and P. atriplicifolia, but only Gaura exhibited persistent growth reductions at 8 WAP.

VI Symposium on Stand Establishment and ISHS Seed Symposium

Joyce G. Latimer, P. Lewis, Paul A. Thomas

daminozide, B-Nine, chlormequat chloride, Cycocel, uniconazole, Sumagic, Autumn sage, Salvia greggii, heliotrope, Heliotropium arborescens, blanketflower,Gaillardia grandiflora, Russian sage, Perovskia atriplicifolia, white gaura, Gaura lindeheimeri, Mexican sage, Salvia leucantha

https://doi.org/10.17660/ActaHortic.1999.504.8