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Paul B. Redman and John M. Dole

The postharvest attributes of six specialty cut flower species were studied. First year results indicate that Achillea filipendulina `Coronation Gold' had a vase-life of 10.7 days in deionized water (DI) and can be stored one week at 1.7°C and shipped for one day. Buddeleia davidii (Butterfly Bush) had a vase life of 3.8 days in DI water and tolerated two weeks of cold storage and two days of shipping. Celosia plumosa `Forest Fire' (Plume Celosia) had a vase-life of 5.9 days in DI water and tolerated 2 days of shipping. Cercis canadensis (Redbud) had a vase-life of 9 days in DI water and tolerated one day of shipping. Echinacea purpurea `Bright Star' (Purple Coneflower) had a vase-life of 4.6 days in DI water and tolerated 2 weeks of storage and five days of shipping. Helianthus maximilianii (Maximillian Sunflower) had a vase-life of 6.3 days in DI water and tolerated one week of storage. In addition, silver thiosulfate and 8-hydroxyquinoline citrate increased vase-life of Buddeleia davidii, Celosia plumosa, Echinacea purpurea, and Helianthus maximilianii.

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John M. Dole and Harold F. Wilkins

Easter lily (Lilium longiflorum Thunb. `Nellie White') bulbs were exposed to 1, 2, 3, 4, 5, or 6 weeks of cold before shoot emergence; 0, 1, 2, 3, 4, 5, or 6 weeks of long days (LD) upon shoot emergence; or a combination of cold followed by LD: 1/5 (weeks cold/weeks LD), 2/4,3/3,4/2, or 5/1. Experiments were repeated for three consecutive years. LD did not substitute equally for cold; at least 3 weeks of cold were required before LD treatments resulted in anthesis. Depending on the year, 100% of the plants flowered when treated with 3 to 6 weeks of cold alone or in combination with LD. Days to first flower anthesis from planting increased with decreasing weeks of cold in years 1 and 3, but was similar for all treatments in year 2. Decreasing weeks of cold in combination with LD, however, decreased days to anthesis in years 1 and 2, but had no effect in year 3. Regardless of LD, days from emergence to visible bud increased with decreasing weeks of cold in all years, and days to emergence from placement in the greenhouse increased with decreasing cold in years 1 and 3, but not in year 2. Increasing weeks of cold, regardless of LD, decreased leaf count, but had no effect on plant height. Flower count was unaffected by cold when combined with LD, but was significantly reduced by increasing weeks of cold.

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John M. Dole and Harold F. Wilkins

Easter lily bulbs (Lilium longiflorum `Nellie White') were given 6 weeks of cold, placed in the greenhouse and subsequently divided into groups based on emergence date after placement in the greenhouse: 0-6, 7-13, 14-20 and 21-27 days. At emergence bulbs received 0, 1, 2 or 3 weeks of long days (LD). Late-emerging plants had fewer days to visible bud and anthesis from emergence than early-emerging plants; consequently, late-emerging plants flowered within 3-10 days of early emerging plants despite 14-21 days difference in emergence time. Late emerging plants were tallest and middle emerging plants had the highest leaf number. Increasing LD tended to decrease numbers of days from emergence to visible bud and anthesis and increase plant height. LD did not effect leaf or flower number. Interactions between LD and emergence date will be discussed. Experiment was repeated for three consecutive years.

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Janet C. Cole and John M. Dole

A 3 pine bark: 1 peatmoss: 1 sand (by volume) medium was amended with 7.7 g P as superphosphate, triple superphosphate, ammonium phosphate, or controlled-release ammonium phosphate per 1000 g medium (3.8 liters). The medium was then leached with 250, 350, or 450 ml distilled, deionized water daily for 25 days. Phosphorus leaching curves were then generated for each fertilizer. A subsequent study determined the effect of these four P fertilizers on growth of marigold seedlings in the greenhouse. Superphosphate, triple superphosphate, and ammonium phosphate rapidly leached from the medium, while the controlled-release ammonium phosphate was retained for a longer time. Marigold growth was not affected by fertilizer type; however, marigolds grown in P-amended media were larger than those grown without P. These studies indicate that amending container growing medium with superphosphate or triple superphosphate prior to planting may not be cost-effective.

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Alicain S. Carlson and John M. Dole

The effects of production temperature and transplant stage on stem length and caliper of cut stems and postharvest treatments on vase life of ‘Esprit’ penstemon (Penstemon grandiflorus) were examined. Plugs transplanted with eight to nine sets of true leaves had a longer stem length (64.3 cm) at harvest than those transplanted with two to three sets (57.7 cm) or five to six sets (60.8 cm). Time to flowering from transplant shortened as production temperature increased and when transplants had a greater number of true leaves. The addition of 2% or 4% sucrose with 7 ppm isothiazolinone as a vase solution resulted in the longest vase life (9.4 days) of all treatments compared with the control (4.5 days). A holding solution increased vase life to 7.0 days for Floralife holding solution and 5.9 days for Chrysal holding solution from the 4.3 days control, although hydrating solutions and preservative brand had no effect. The use of floral foam or antiethylene agents, ethylene exposure, or sucrose pulses also had no effect on vase life. Extended cold storage lengths either wet or dry for 2 or 3 weeks caused vase life to decrease to 2.0 days when compared with 5.6 days for the unstored control and 7.6 days for 1 week storage. ‘Esprit’ penstemon may be suitable for greenhouse production and has acceptable potential as a locally grown specialty cut flower.

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John M. Dole and Harold F. Wilkins

Vegetative, single-stem poinsettia plants (Euphorbia pulcherrima Willd. `Gutbier V-14 Glory') were allowed to develop 10, 15, or 20 nodes (nodal groups). Within each nodal group, blades from the same node position were removed, combined into one sample per node, and analyzed for nutrient content. Nutrient concentrations were found to be distributed within the plant in one of three patterns: 1) N, P, and K concentrations were higher in upper than in lower leaves; 2) Ca, Mg, Fe, Mn, and B concentrations were higher in lower than in upper leaves; and 3) Cu and Zn concentrations were higher in upper and lower leaves than in middle leaves. When 10, 15, and 20 noded groups were compared, the distributional patterns were similar, but actual nutrient concentrations between groups differed. Leaf P, Ca, Mg, Fe, Mn, Zn, and B concentrations increased over time. However, concentrations of N, K, and Cu were highest in 43-day-old leaves and lowest in 19-day-old leaves for N and Cu and lowest in 67-day-old leaves for K.

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Alicain S. Carlson and John M. Dole

Pineapple lily (Eucomis hybrids) has long, striking inflorescences that work well as a cut flower, but information is needed on proper production methods and postharvest handling protocols. The objective of this study was to determine the effects of bulb storage temperature and duration, production environment, planting density, and forcing temperatures on cut flower production of ‘Coral’, ‘Cream’, ‘Lavender’, and ‘Sparkling Burgundy’ pineapple lily. Stem length was greater in the greenhouse than the field and at the low planting density. Plants in the field at the low planting density had the shortest stem length for ‘Coral’ and ‘Cream’, but still produced marketable lengths of at least 30 cm. Planting density did not affect ‘Lavender’ and ‘Sparkling Burgundy’ stem length or number of marketable stems. The productivity (number of marketable stems per bulb) was affected only by planting density for ‘Coral’ and planting environment for ‘Cream’. Differences in stem quality and productivity differed for each cultivar and planting density over the next two seasons. The productivity of ‘Coral’ increased significantly from year to year, while the productivity of ‘Cream’ only significantly increased between the first and second years. The low planting density resulted in slightly more stems per bulb for ‘Coral’ over the next two seasons. Emergence after bulb storage treatments was highest in treatments where the bulbs were not lifted from the substrate and were subsequently grown at 18 °C. Bulbs grown in the warmest (18 °C) production temperature flowered soonest and had shorter stem lengths. For earliest flowering, bulbs should be stored in substrate in cool temperatures of at least 13 °C and forced at warm temperatures of at least 18 °C.

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Janet C. Cole and John M. Dole

These studies were conducted to determine the effect of 1) temperature on P leaching from a soilless medium amended with various P fertilizers, 2) water application volume on P leaching, and 3) various fertilizers on P leaching during production and growth of marigolds (Tagetes erecta L. `Hero Flame'). Increasing temperature linearly decreased leaching fraction; however, total P leached from the single (SSP) or triple (TSP) superphosphate-amended medium did not differ regardless of temperature. Despite a smaller leaching fraction at higher temperatures and no change in the total P leached, P was probably leached more readily at higher temperatures. More P was leached from the medium amended with uncoated monoammonium phosphate (UCP) than from the medium containing polymer-coated monoammonium phosphate (CTP) at all temperatures, and more P was leached from UCP-amended medium at lower temperatures than at higher temperatures. More P was leached from TSP- than from SSP-amended medium and from UCP- than from CTP-amended medium regardless of the water volume applied, but leachate P content increased linearly as water application volume increased for all fertilizers tested. Plant dry weights did not differ regardless of P source. Leachate electrical conductivity (EC) was lower with TSP than with SSP. Leachate EC was also lower with CTP than with UCP. A higher percentage of P from controlled release fertilizer was taken up by plants rather than being leached from the medium compared to P from uncoated fertilizers.

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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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John M. Dole and Michael A. Schnelle

Oklahoma floriculture producers, ornamental-horticulture retailers, mass-market retailers, and cut-flower wholesalers were surveyed to compare and contrast the industry in terms of attitudes towards their products and problems. Overall, attitudes of all four segments of the industry were neutral to negative on potted flowering plants, but were positive to neutral on bedding and foliage plants. However, producers were slightly negative concerning the postharvest life of bedding plants. While cut-flower wholesalers had a positive attitude concerning cut flowers, ornamental-horticulture retailers and mass-marketers tended to be neutral to negative. In particular, retailers and mass-marketers believed that cut flowers were too expensive and too short-lived. Floral preservatives were used by 82% of ornamental-horticulture retailers, while only 19% of mass-market retailers used preservatives. All cut-flower wholesalers used preservatives. Capital availability and market demand were the factors most limiting expansion for producers and ornamental-horticulture retailers; whereas mass-market firms listed competition as their most limiting factor.