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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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John M. Dole, Paul Fisher, and Geoffrey Njue

Several treatments were investigated for increasing vase life of cut `Renaissance Red' poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch.) stems. A vase life of at least 20.6 days resulted when harvested stems were placed directly into vases with 22 °C deionized water plus 200 mg·L-1 8-HQS (the standard floral solution used) and 0% to 1% sucrose without floral foam. Maturity of stems at harvest, ranging from 0 to 4 weeks after anthesis, had no effect on vase life or days to first abscised leaf. Pretreatments immediately after harvest using floral solution heated to 38 or 100 °C, or 1 or 10-min dips in isopropyl alcohol, had no effect, whereas 24 hours in 10% sucrose shortened vase life by 6.4 days and time to first abscised cyathium by 4.5 days. Stem storage at 10 °C decreased vase life, particularly when stems were stored dry (with only 0.8 days vase life after 3 weeks dry storage). Increasing duration of wet storage in floral solution from 0 to 3 weeks decreased vase life from 21.5 to 14.6 days. Placing cut stems in a vase containing floral foam decreased time to first abscised leaf by 3.7 to 11.6 days compared with no foam. A 1% to 2% sucrose concentration in the vase solution produced the longest postharvest life for stems placed in foam but had little effect on stems not placed in foam. A 4% sucrose concentration decreased vase life compared with lower sucrose concentrations regardless of the presence of foam. Holding stems in the standard floral solution increased vase life and delayed leaf abscission compared with deionized or tap water only, with further improvement when stem bases were recut every three days. Commercial floral pretreatments and holding solutions had no effect on vase life and days to first abscised cyathium but delayed leaf abscission.

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Frank Blazich Jr. and John M. Dole

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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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Alicain S. Carlson and John M. Dole

The effects of various postharvest treatments on cut stems of ‘Coral’ and ‘Sparkling Burgundy’ pineapple lily (Eucomis sp.) were evaluated to determine best postharvest handling practices. The use of a commercial hydrator, holding solution, or both significantly reduced vase life for ‘Coral’; the deionized (DI) water control had the longest vase life. ‘Sparkling Burgundy’ vase life was significantly reduced to 29.9 days when both a commercial hydrator and holding solution were used as compared with 50.3 days when DI water was the hydrator used with the commercial holding solution. The use of a bulb-specific preservative reduced vase life of ‘Coral’ to 43.8 days, while the DI water control had a vase life of 66.4 days, and commercial holding solution was intermediate at 56.8 days. A 10% sucrose pulse reduced vase life to 46.9 days compared with the 0% sucrose control (58.9 days) and the 20% sucrose concentration (62.5 days), which were not significantly different. The use of floral foam and/or 2% or 4% sucrose concentrations plus isothiazolinone reduced vase life significantly to an average of 11.1 days. The vase life of stems cold stored at 2 °C for 1 week (37.7 days) was not significantly different from the unstored stems (43.0 days), while longer storage times up to 3 weeks significantly reduced vase life. The use of hydrating solution pretreatments before and holding solution treatments during 4 days of cold storage had no significant effect on vase life. ‘Sparkling Burgundy’ stems harvested with 100% of the florets open had the longest vase life of 51.2 days compared with 38.4 days when 1% of the florets were open. Vase life was unaffected by exogenous ethylene exposure up to 1 ppm for 16 hours. For best postharvest quality, ‘Coral’ and ‘Sparkling Burgundy’ pineapple lily should be harvested when at least 50% of the florets are open, held in plain water without preservatives, and stored for no more than 1 week (wet or dry) at 2 °C.

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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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John M. Dole and Harold F. Wilkins

Poinsettia (Euphorbia pulcherrima Wind. ex. Klotzsch) cultivars were divided into free-branching and restricted-branching groups. Auto and reciprocal grafts were made among three free-branching cultivars, Annette Hegg Brilliant Diamond (BD), Annette Hegg Topwhite (TW), and Annette Hegg Hot Pink (HP), and two restricted-branching cultivars, Eckespoint C-1 Red (CR) and Eckespoint C-1 White (CW). when CR scions were grafted onto BD stocks, vegetative characteristics of branching pattern and leaf morphology of CR plants were altered when compared to the control graft combination CR/CR (scion/stock). Branching pattern was determined by pinching the scion above the 12th node and measuring axillary shoot length, diameter, and node number 30 days later. CR scions grafted onto BD stocks produced a plant very similar to BD plants when axillary shoot length and node number were compared. However, axillary shoot diameter and leaf morphology were intermediate between CR and BD plants. Changes were retained after two generations of serial vegetative propagation and are considered permanent. The reproductive characteristics of anthesis date, bract color, and cyathia cluster diameter were not influenced by the stock. CR/BD plants produced twice as many axillary inflorescences as BD/BD or BD/CR plants, while CR/CR plants did not produce any. All of the free-branching cultivars were able to alter the vegetative characteristics of all of the restricted-branching cultivars.

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John M. Dole and Harold F. Wilkins

The free-branching poinsettia (Euphorbia pulcherrima Willd. ex. Klotzsch) cultivar Annette Hegg Brilliant Diamond (BD) contained a free-branching agent that was graft-transmissible to the restricted-branching cultivar Eckespoint C-1 Red (CR). CR plants were transformed by the agent regardless of whether BD plants were used as scion or stock, indicating that the agent moved basipetally and acropetally through the graft union. The agent was repeatedly transmitted to a CR plant by serial grafting with a free-branching poinsettia plant. A minimum of 10 days contact through grafting was required for BD plants to transmit the agent to CR plants. Percentage of CR plants exhibiting the free-branching characteristic increased from 0% for < 10 days of graft contact with BD plants to 100% after 30 days.

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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.

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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.