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Laurence C. Pallez and John M. Dole

The purple velvet plant (Gynura aurantiaca) has commercial potential as a potted plant due to its attractive purple foliage, if the malodorous flowers can be avoided. Plants were treated with seven concentrations of ethephon, three photoperiodic durations, three light intensities, and combinations of photoperiod and light intensity to inhibit flowering. Although foliar application of ethephon at 1200 to 4800 ppm (μL·L-1) completely inhibited flowering of purple velvet plants, plants were stunted and cutting harvest was impossible. Flowering was promoted at lower application rates of 150 to 300 ppm (μL·L-1). An 8-hour photoperiod increased plant quality and plants had the largest vegetative shoot number and the brightest purple color, compared to 12 or 16-hour photoperiods. All of the shoots were reproductive under the 16-hour photoperiod. Increasing the shade level from 0 to 60% (790 μmol·m-2·s-1 to 230 μmol·m-2·s-1) increased the number of vegetative shoots at 74 and 108 days after treatment commenced but reduced the total number of shoots by 28% at day 108. Plants grown under60% shade and short days had 94% vegetative shoots 102 days after placement in treatment. Growing plants under 8-hour photoperiod and 60% shade from fall to spring is recommended to maintain vegetative stock plants and produce high quality marketable plants. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon).

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Laurence C. Pallez, John M. Dole and Brian E. Whipker

Sunflower (Helianthus annuus) has potential as a potted flowering plant due to short crop time, ease of propagation, and attractive flowers but postharvest life is short and plants can grow too tall. Days from sowing to anthesis differed significantly among six sunflower cultivars and ranged from 52 days for `Big Smile' to 86 days for `Elf' and `Pacino.' Height ranged from 6.0 inches (15.2 cm) for `Big Smile' to 14.9 inches (37.8 cm) for `Pacino', postproduction life ranged from 10 days for `Elf' and `Pacino' to 15 days for `Big Smile', and postproduction chlorosis ratings (1 to 5, with 5 the least) ranged from 5.0 for `Teddy Bear' to 4.4 for `Big Smile' after 5 days and 4.2 for `Teddy Bear' to 3.1 for `Sunspot' after 10 days. Promalin (a gibberellin and benzyladenine mixture) applied at 62.5 to 500 ppm (mg·L-1) was not commercially useful in extending postproduction life. Increasing pot size from 4 to 6 inches (10 to 15 cm) in diameter decreased postproduction life and plants in 5-inch-diameter (13 cm) pots were tallest. Pots with three plants flowered more quickly than those with one or five plants and pots with five plants had 1 day shorter postharvest life than those with one or three pots. All cultivars were facultative short-day plants, except for `Sundance Kid', which was day neutral. Storing potted sunflowers at 41 °F (5 °C) for 1 week did not reduce postproduction life, which was 11 to 12 d; however, 2 weeks of cold storage resulted in foliar damage. Three cultivars were found to be most suitable for pot production, `Elf', `Pacino' and `Teddy Bear', with one or three plants per 6-inch pot and sprayed with daminozide (B-Nine) at 8,000 ppm, or drenched with paclobutrazol (Bonzi) at 2 mg/pot (a.i.) (28,350 mg = 1.0 oz).

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Laurence C. Pallez, John M. Dole and Brian E. Whipker

Days from sowing to anthesis were significantly different among six sunflower (Helianthus annuus L.) cultivars and ranged from 52 days for `Big Smile' to 87 days for `Pacino'. Height ranged from 13.5 cm for `Big Smile' to 37.3 cm for `Pacino'. Postproduction life ranged from 10 days for `Pacino' and `Elf' to 15 days for `Big Smile'. Postproduction quality ratings (1 to 5, with 5 the best) ranged from 3.9 to 5 after 5 days and 1 to 4.2 after 10 days. Quality ratings after 15 days were not significantly different among cultivars, because few plants were marketable at 15 days. Increasing the number of plants per pot from one to three or five reduced number of days to anthesis and postproduction life. Pot sizes of 10-, 13-, or 15-cm diameter, had no influence on production or postproduction characteristics. Promalin (62.5 to 500.0 mg·L–1) was not commercially useful in extending postproduction life. Two cultivars were found to be most suitable for pot production, `Pacino' and `Teddy Bear', with one plant per 15-cm pot and sprayed with B-Nine at 8000 mg·L–1.