scholarly journals Vernalization in a Greenhouse Promotes and Synchronizes Flowering of Osteospermum ecklonis Norl.

HortScience ◽  
2001 ◽  
Vol 36 (4) ◽  
pp. 658-660 ◽  
Author(s):  
Ayumi Suzuki ◽  
James D. Metzger
Keyword(s):  
Flower Development ◽  
Stem Growth ◽  
Cool Temperature ◽  
Flower Number

The effect of cool temperature treatments on flowering of Osteospermum ecklonis Norl. cv. Nairobi was evaluated. Plants vernalized at temperatures from 4 to 15 °C for 4 to 6 weeks exhibited increased flower numbers, more synchronized flower development among individual plants, and reduced forcing times. Part of the increased flower number observed in the vernalized plants could be attributed to a small increase in branch numbers from 2 to 3. However, a longer period of vernalization slowed flower development, and therefore increased overall production times. Vernalization also reduced stem growth, primarily through a reduction in the number of nodes produced by each branch.

scholarly journals Photoperiod, Irradiance, and Temperature Affect Echinopsis ‘Rose Quartz’ Flowering

HortScience ◽  
2016 ◽  
Vol 51 (12) ◽  
pp. 1494-1497
Author(s):  
John Erwin ◽  
Rene O’Connell ◽  
Ken Altman
Keyword(s):  
Flower Development ◽  
Flowering Plants ◽  
Cool Temperature ◽  
Total Production ◽  
Spray Application ◽  
Night Temperature ◽  
Flower Number ◽  
Production Time ◽  
Supplemental Lighting ◽  
Short Days

Photoperiod, irradiance, cool temperature (5 °C), and benzyladenine (BA) application effects on Echinopsis ‘Rose Quartz’ flowering were examined. Plants were placed in a 5 °C greenhouse under natural daylight (DL) for 0, 4, 8, or 12 weeks, then moved to a 22/18 °C (day/night temperature) greenhouse under short days (SD, 8-hour DL) plus 0, 25, 45, or 75 μmol·m−2·s−1 supplemental lighting (0800–1600 hr; 8-hour photoperiod), long days (LD) delivered with DL plus night-interruption lighting (NI) (2200–0200 hr), or DL plus 25, 45, or 75 μmol·m−2·s−1 supplemental lighting (0800–0200 hr) for 6 weeks. Plants were then grown under DL only. Percent flowering plants increased as irradiance increased from 0–25 to +75 μmol·m−2·s−1 on uncooled plants, from 0% to 100% as 5 °C exposure increased from 0 to 8 weeks under subsequent SD and from 25% to 100% as 5 °C exposure increased from 0 to 4 weeks under subsequent LD. As 5 °C exposure duration increased from 0 to 12 weeks (SD-grown) and from 0 to 8 weeks (LD-grown), flower number increased from 0 to 11 and from 5 to 21 flowers per plant across irradiance treatments, respectively. Total production time ranged from 123 to 147 days on plants cooled from 8 to 12 weeks (SD-grown) and from 52 to 94 days on plants cooled for 0–4 weeks to 119–153 days on plants cooled for 8–12 weeks (LD-grown). Flower life varied from 1 to 3 days. BA spray application (10–40 mg·L−1) once or twice after a 12-week 5 °C exposure reduced flower number. Flower development was not photoperiodic. High flower number (17–21 flowers/plant) and short production time (including cooling time, 120–122 days) occurred when plants were grown at 5 °C for 8 weeks, then grown under LD + 45–75 μmol·m−2·s−1 for 6 weeks (16 hours; 10.9–12.8 mol·m−2·d−1) at a 22/18 °C day/night temperature. Taken together, Echinopsis ‘Rose Quartz’ exhibited a facultative cool temperature and facultative LD requirement for flowering.

Effect of High Temperatures on the Postharvest Flowering of Specialty Floral Crop Species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447f-448
Author(s):  
Millie S. Williams ◽  
Terri Woods Starman ◽  
James E. Faust
Keyword(s):  
United States ◽  
Heat Tolerance ◽  
Flower Development ◽  
Consumer Satisfaction ◽  
The United States ◽  
Plant Canopy ◽  
Flower Number ◽  
Flower Bud ◽  
Crop Species ◽  
Mature Flower

Flower growers experience decreased consumer satisfaction with plant species that cease flowering during the summer. The objective of this experiment was to characterize the heat tolerance of four specialty floral crop species in order to predict their summer performance in the different climatalogical regions of the United States. The effect of increasing temperatures on the duration of postharvest flower development was determined for Ageranthemum frutescens `Butterfly' and `Sugar Baby', Brachycome hybrid `Ultra', and Sutera cordata `Snowflake'. Plants were grown in a 18 °C greenhouse until marketable with foliage covering the container and flowers distributed evenly across the plant canopy. Plants were then placed in a phytotron to determine their heat tolerance. Temperature set points of 18, 23, 28, and 33 °C were delivered serially at 2-week intervals, starting at 18 °C. Plants were then returned to 18 °C after the 33 °C treatment. Immature flower bud, mature flower bud, flower and senesced flower numbers were collected once per week. Sutera `Snowflake', and Brachycome `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argeranthemum `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were smaller and of lower quality than at 23 °C. Flower development of all cultivars ceased at 33 °C, but when plants were returned to the 18 °C production greenhouse, flower development resumed. According to normal average daily temperatures in Knoxville, Tenn., Ageranthemum frutescens `Butterfly' and `Sugar Baby' would flower until mid-June, while Brachycome hybrid `Ultra' and Sutera cordata `Snowflake' would flower until mid-May.

scholarly journals Prevernalization Daily Light Integral and Vernalization Temperature Influences Flowering of Herbaceous Perennials

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1028-1031 ◽  
Author(s):  
Genhua Niu ◽  
Royal Heins ◽  
Arthur Cameron ◽  
William Carlson
Keyword(s):  
Plant Height ◽  
Flower Development ◽  
Flower Number ◽  
Lavandula Angustifolia ◽  
Herbaceous Perennials ◽  
Daily Light Integral ◽  
Delayed Flowering ◽  
Light Integral

The influence of daily light integral (DLI) before vernalization and vernalization temperature and duration on growth and flower development was determined for seed-propagated perennials Aquilegia ×hybrida Sims `Remembrance', Coreopsis grandiflora Hogg ex Sweet `Sunray', and Lavandula angustifolia Mill. `Hidcote Blue'. Seedlings were grown under two DLIs (4 or 14 mol·m-2·d-l) for 5 weeks before being vernalized at -2.5, 0, 2.5, or 5 °C for 2,4,5, or 8 weeks. `Remembrance' and `Sunray' plants were vernalized in the dark, while `Hidcote Blue' plants were vernalized in light at 5 to 10 μmol·m-2·s-l for 9 hourslday. After vernalization, plants were forced under a 16-h photoperiod in the greenhouse at 20±2 °C. `Remembrance' plants flowered uniformly when vernalized at 0 to 2.5 °C for 2 weeks or longer, and flower number, plant height, time to visible bud or to flower were generally not influenced by vernalization temperature or duration. No `Sunray' plants flowered without vernalization, and only a low percentage flowered with 4-week vernalization. Compared with low DLI, a 14 mol·m-2·d-1 before vernalization delayed flowering by 7 to 20 days in `Remembrance', but there were no substantial differences in flowering characteristics of `Sunray'. `Hidcote Blue' plants were best vernalized in the light at 5 °C for 8 weeks to obtain rapid and uniform flowering and the highest number of inflorescences. Flowering and survival percentages of `Hidcote Blue' were much lower for plants at 14 mol·m-2·d-l DLI compared to 4 mol·m-2·d-1.

Application of Photoperiodic Manipulation in Vegetative Specialty Floral Crop Propagation and Flowering

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 554d-554
Author(s):  
Millie S. Williams ◽  
Terri Woods Starman
Keyword(s):  
Flowering Time ◽  
Flower Development ◽  
Vegetative Growth ◽  
Plant Production ◽  
Flower Initiation ◽  
Stock Plant ◽  
Flower Number ◽  
Open Flower ◽  
Long Day ◽  
Photoperiodic Responses

Photoperiod requirements are important for optimum flower development, decreasing production time, year-round flowering, and/or for increasing vegetative growth necessary in stock plant production. The photoperiodic responses were determined for 24 vegetatively propagated specialty floral crops. Each plant species was grown at 8-, 10-, 12-, 14-, and 16-h photoperiods. Photoperiods were provided by 8 h of sunlight, then pulling black cloth and providing daylength extension with incandescent bulbs. Data collected included time to flower, flower number, and vegetative characteristics. Evolvulus nuttallianus `Blue Daze', Heliotropium arborescens `Fragrant Delight', and Orthosiphon stamineus `Lavender' were facultative short-day plants with respect to flowering. Time to flower increased as photoperiod increased. Duranta repens `Blue', Verbena hybrid `Tapien Lavender', and Verbena peruviana `Trailing Katie' were facultative long day plants with respect to flowering. Days to visible bud and first open flower decreased as photoperiod increased. Argeranthemum frutescens `Sugar Baby', Scaevola aemula `Fancy Fan Falls', and Portulaca hybrid `Apricot' had increased flower number as photoperiod increased from 8- to 16-h, although time to first flower initiation was not affected. Abutilon hybrid `Apricot', Duranta repens `Blue', Evolvulus nuttallianus `Blue Daze', Lotus berthelotii `Parrot's Beak', Lysimachia nummularia `Aurea Creeping Golden', Rhodanthe anthemoides `Milkyway', and Scaevola aemula `Fancy Fan Falls' had increased vegetative growth as photoperiod increased. All other species studied were day-neutral with regard to flowering and vegetative parameters.

Effect of Phosphorus Nutrition and Cytokinins on Flowering in the Tomato, Lycopersicon esculentum Mill

1976 ◽  
Vol 3 (2) ◽  
pp. 201 ◽  
Author(s):  
RC Menary ◽  
JV Staden
Keyword(s):  
Lycopersicon Esculentum ◽  
Flower Development ◽  
Root Exudate ◽  
Phosphorus Deficiency ◽  
Zeatin Riboside ◽  
Cytokinin Activity ◽  
Flower Number ◽  
Tomato Plants ◽  
Preliminary Identification ◽  
Growing Medium

Ten days of phosphorus deficiency results in a decrease in the number of flowers that develop on the first truss of tomato plants. This effect on flower number is accompanied by a decrease in the cytokinin activity of the root exudate. The involvement of cytokinins in flower development is further implicated by the fact that application of kinetin to the growing medium increased the number of flowers produced by the seedlings. Preliminary identification of cytokinins in root exudate has revealed the presence of compounds that cochromatograph with zeatin and zeatin riboside on Sephadex LH20.

scholarly journals (233) Comparison of Inflorescence Morphology, Anthesis and Floral Sex Expression in Bottlebrush and Red Buckeye

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1020B-1020
Author(s):  
Ann M. Chanon ◽  
Pablo S. Jourdan ◽  
Joseph C. Scheerens
Keyword(s):  
Interspecific Hybridization ◽  
Flower Development ◽  
Floral Biology ◽  
Sex Expression ◽  
Flower Number ◽  
Apical Portion ◽  
Inflorescence Morphology ◽  
Basal Portion ◽  
Male Flowers ◽  
Morphology Pattern

As a prelude to interspecific hybridization, we compared the floral biology of bottlebrush buckeye (Aesculus parviflora) and red buckeye (A. pavia) by examining inflorescence morphology, pattern of floral anthesis, sex expression, and the effects of panicle decapitation on complete flower development. Inflorescences of both species (n = 1606) were randomly selected and analyzed for length, total number of flowers and complete flower number and location. The pattern of anthesis was observed in four genotypes using 10–30 inflorescences per plant. For each flower, its date of anthesis, position on both the rachis and cincinnus, and sex were recorded. For studies of panicle decapitation, sets of panicles were selected and one member was severed in half early in development in an attempt to increase the number of complete flowers. More than one-fourth of all panicles observed were completely staminate. For both species, the ratio of complete flowers to male flowers (C:M) within mixed panicles was about 5%. Complete flowers were observed in the basal portion of A. pavia inflorescences and in the apical portion of A. parviflora inflorescences. Anthesis progressed from base to tip over a period of 6–11 days. Complete flowers are present in A. pavia from the beginning of anthesis but do not appear in A. parviflora until the fifth day of anthesis. Staminate flowers are present throughout anthesis in both species. Severing panicles in half increased the potential for differentiating complete flowers. In conclusion, the frequency of complete flowers in both species was quite low, but could be increased by panicle decapitation to increase opportunities for controlled hybridization.

scholarly journals Flower-Specific Overproduction of Cytokinins Altered Flower Development and Sex Expression in the Perennial Woody Plant Jatropha curcas L.

2020 ◽  
Vol 21 (2) ◽  
pp. 640 ◽  
Author(s):  
Xin Ming ◽  
Yan-Bin Tao ◽  
Qiantang Fu ◽  
Mingyong Tang ◽  
Huiying He ◽  
...  
Keyword(s):  
Jatropha Curcas ◽  
Flower Development ◽  
Sex Expression ◽  
Fine Tuning ◽  
Flower Number ◽  
Transgenic Expression ◽  
Jatropha Curcas L ◽  
Male Ratio ◽  
Mads Box Gene ◽  
Pistil Development

Jatropha curcas L. is monoecious with a low female-to-male ratio, which is one of the factors restricting its seed yield. Because the phytohormone cytokinins play an essential role in flower development, particularly pistil development, in this study, we elevated the cytokinin levels in J. curcas flowers through transgenic expression of a cytokinin biosynthetic gene (AtIPT4) from Arabidopsis under the control of a J. curcas orthologue of TOMATO MADS BOX GENE 6 (JcTM6) promoter that is predominantly active in flowers. As expected, the levels of six cytokinin species in the inflorescences were elevated, and flower development was modified without any alterations in vegetative growth. In the transgenic J. curcas plants, the flower number per inflorescence was significantly increased, and most flowers were pistil-predominantly bisexual, i.e., the flowers had a huge pistil surrounded with small stamens. Unfortunately, both the male and the bisexual flowers of transgenic J. curcas were infertile, which might have resulted from the continuously high expression of the transgene during flower development. However, the number and position of floral organs in the transgenic flowers were well defined, which suggested that the determinacy of the floral meristem was not affected. These results suggest that fine-tuning the endogenous cytokinins can increase the flower number and the female-to-male ratio in J. curcas.

scholarly journals Photoperiod, Irradiance, and Cool Temperature Effects on Gymnocalycium, Rebutia, Lobivia, and Sulcorebutia sp. Growth and Flowering

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 992B-992
Author(s):  
John Erwin ◽  
Esther Gesick ◽  
Ben Dill ◽  
Charles Rohwer
Keyword(s):  
High Pressure ◽  
Temperature Effects ◽  
Vernalization Requirement ◽  
Cool Temperature ◽  
Flower Longevity ◽  
Night Temperature ◽  
Flower Number ◽  
Response Groups

A study was conducted to determine if photoperiod, irradiance, and/or a cool temperatures impacted flowering of selected species in five cactus genera. Gymnocalycium, Rebutia, Lobivia, and Sulcorebutia plants were grown for 4 months under natural daylight conditions (August–November) in a greenhouse maintained at 26 ± 2 °C. Plants were then placed in either of two greenhouses: 1) a greenhouse maintained at 22 °C day/18 ± 1 °C night temperature with an 8-h daylength (SD) or natural daylight plus night interruption lighting (NI; 2200–0200 HR), or 2) a greenhouse maintained at 5 ± 2 °C under natural daylight conditions (8–10 h). After 12 weeks at 5 °C, plants were moved to the SD and NI lighting treatments in the before mentioned greenhouse and additional lighting treatment [natural daylight plus supplemental high-pressure sodium lighting (85–95 μmol·m-2·s-1; 0800–0200 HR)]. In all cases, plants were moved out of lighting treatments after 6 weeks and were then grown under natural daylight conditions in a greenhouse maintained at constant 22 ± 1 °C. Data were collected on the approximate date growth commenced, the date when each flower opened (five flowers only), flower number per plant, and individual flower longevity (five flowers only). Species were classified into photoperiodic and irradiance response groups where appropriate and whether species exhibited a vernalization requirement was reported. Lastly, whether dormancy occurred and what conditions overcame that dormancy was reported.

scholarly journals (76) Photoperiod, Irradiance, and/or Cool Temperature Effects on Mamillopsis senilis, Echinopsis Hybrid, and Trichocereus Hybrid Growth and Flowering

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1065D-1066
Author(s):  
John Erwin ◽  
Esther Gesick ◽  
Ben Dill ◽  
Charles Rohwer
Keyword(s):  
High Pressure ◽  
Temperature Effects ◽  
Cool Temperature ◽  
Vernalization Response ◽  
Night Temperature ◽  
Flower Number ◽  
Hybrid Growth ◽  
Response Groups ◽  
Incandescent Lamps ◽  
The Impact

The impact of photoperiod, irradiance, and/or cool temperature on flowering and/or dormancy in Mamillopsis senilis and Echinopsis and Trichocereus hybrids was studied. Two- to 3-year-old plants (180 plants of each type) were grown for 4 months under natural daylight (DL) conditions (August–November) in a greenhouse maintained at 26 ± 2 °C. Plants were then placed in either of two greenhouses: a cool temperature house (5 ± 2 °C; DL), or a lighting treatment house (22/18 ± 1 °C day/night temperature, respectively). The lighting treatment house had eight light environments: 1) short day (SD; 8 h; 0800–1600 hr); 2) SD+25–35 μmol·m-2·s-1; 3) SD+45–50 μmol·m-2·s-1; 4) SD+85–95 μmol·m-2·s-1; 5) DL plus night interruption lighting (NI; 2200–0200 hr; 2 μmol·m-2·s-1 from incandescent lamps); 6) DL+25–35 μmol·m-2·s-1 (lighted from 0800–0200 hr); 7) DL+45–50 μmol·m-2·s-1; and 8) DL+85–95 μmol·m-2·s-1. Supplemental lighting was provided using high-pressure sodium lamps. Plants were placed in the cool temperature house for 0, 4, 8 or 12 weeks before being placed under lighting treatments. All plants received lighting treatments for 6 weeks and were then placed in a finishing greenhouse (DL; 22 ± 2 °C). Data were collected on approximate day when growth resumed, the date when each flower opened (five only), total flower number per plant, and how long each flower stayed open (five only). Whether species exhibited dormancy and what conditions, if any, broke that dormancy was identified. Species were also classified into photoperiodic, irradiance, and vernalization response groups with respect to flowering.

scholarly journals High Temperatures Reduce Postharvest Flowering of Specialty Floral Crop Species

1999 ◽  
Vol 9 (1) ◽  
pp. 94-98
Author(s):  
Millie S. Williams ◽  
Terri W. Starman ◽  
James E. Faust
Keyword(s):  
High Temperatures ◽  
Heat Tolerance ◽  
Flower Development ◽  
Flower Number ◽  
Flower Bud ◽  
Crop Species ◽  
Specialty Crop ◽  
Swan River ◽  
Warm Climates

The effect of increasing temperatures on the duration of postharvest flower development was determined for three specialty crop species: marguerite (Argyranthemum frutescens Webb ex Schultz-Bip.) `Butterfly' and `Sugar Baby'; swan river daisy (Brachycome hybrid Cass.) `Ultra'; and bacopa (Sutera cordata Roth.) `Snowflake'. Plants were grown in a greenhouse at 18 °C (65 °F) until flowering, and then transferred into a phytotron to determine heat tolerance. Plants were stored for 8 weeks at constant temperatures of 18, 23, 28, and 33 °C (65, 73, 82, and 91 °F) for 2-week intervals. Flower bud and flower number were recorded weekly. Sutera cordata `Snowflake' and B. hybrid `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argyranthemum frutescens `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were of lower quality thanat 23 °C. Flower development of all cultivars ceased at 33 °C, at the end of 8 weeks at increasing temperatures, but when plants were returned to the 18 °C production greenhouse, flower development resumed. High temperatures (28 °C) reduce the postharvest performance of S. cordata, B. hybrid, and A. frutescens plants grown in hanging baskets; therefore, these species should be marketed as spring-flowering products since summer performance may be unsatisfactory in warm climates.

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