scholarly journals 763 PB 307 ENVIRONMENTAL CONTROL ON FLOWERING AND GROWTH OF LYSIMACHIA CONGESTIFLORA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 542c-542
Author(s):  
Donglin Zhang ◽  
Allan M. Armitage ◽  
James M. Affolter ◽  
Michael A. Dirr
Keyword(s):  
Environmental Control ◽  
Day Treatment ◽  
Dry Weight ◽  
High Irradiance ◽  
Flower Initiation ◽  
Low Light ◽  
The North ◽  
Long Day ◽  
Total Plant ◽  
Lower Temperature

Lysimachia congestiflora Wils. (Primulaceae) is a new crop for American nurseries and may be used as an annual in the north and a half-hardy perennial in the south. The purpose of this study was to investigate the influence of photoperiod, temperature, and irradiance on its flowering and growth. Three experiments were conducted with photoperiod of 8, 12, 16 hrs day-1, temperature of 10, 18, 26C, and irradiance of 100, 200, 300 μmol m-2s-1, respectively. Plant.9 given long day photoperiod (16 hours) flowered 21 and 34 days earlier, respectively, than plants at 12 sad 8 hour photoperiods. Plants under long day treatment produced more flowers than those at 8 and 12 hours. Plant dry weight did not differ between treatments, but plants grown in the long day treatment produced fewer but larger leaves. Total plant growth increased as temperature increased, but lower temperature (10C) decreased flower initiation and prevented flower development, while high temperature (26C) reduced the longevity of the open flowers. Flowering was accelerated and dry weight increased as plants were subjected to high irradiance levels. The results suggest that Lysimachia congestiflora is a quantitative long day plant. It should be grown under a photoperiod of at least 12 hours at a temperature of approximately 20C. Low light areas should be avoided and supplemental lighting to provide the long days may improve the plant quality.

scholarly journals Environmental Control of Flowering and Growth of Lysimachia congestiflora Hemsl.

HortScience ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 62-64
Author(s):  
D. Zhang ◽  
A.M. Armitage ◽  
J.M. Affolter ◽  
M.A. Dirr
Keyword(s):  
High Temperature ◽  
Plant Growth ◽  
Flower Development ◽  
Environmental Control ◽  
Dry Weight ◽  
Flower Initiation ◽  
Optimum Temperature ◽  
Long Day ◽  
Total Plant ◽  
Lower Temperature

Dense-flowered loosestrife is a quantitative long-day (LD) plant. Plants given a LD photoperiod (16 hours) flowered 21 and 34 days earlier than plants given 12- and 8-hour photoperiods, respectively. Plants under LDs produced significantly more flowers than those under 8- and 12-hour photoperiods. Only 1 week of LD was needed for 100% flowering; however, optimum flower count and size were produced with 3 weeks of LD. Plant dry weight did not differ significantly among treatments; however, LDs produced fewer but larger leaves, particularly those subtending the inflorescence. Total plant growth increased as temperature increased, but lower temperature (10C) decreased flower initiation and prevented flower development. High temperature (26C) reduced the persistence of open flowers. The optimum temperature for dense-flowered loosestrife growth was ≈20C. Flowering was accelerated and dry weight production increased as irradiance levels increased from 100 to 300 μmol·m–2·s–1.

scholarly journals Photoperiod, Irradiance, and Temperature Influence Flowering of Hamelia patens (Texas Firebush)

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 255-256 ◽  
Author(s):  
Allan M. Armitage
Keyword(s):  
High Temperature ◽  
Flower Development ◽  
Dry Weight ◽  
Flower Initiation ◽  
Temperature Influence ◽  
Light Conditions ◽  
Low Light ◽  
Long Day ◽  
Critical Photoperiod ◽  
Moderately High Temperature

Hamelia patens Jacq. (Texas firebush) is a long-day plant for flower initiation and flower development; however, flower development is more sensitive to photoperiod than is flower initiation. The critical photoperiod for flower development at 25C is between 12 and 16 hours. Flowering was delayed under low light conditions, and plant dry weight was heavier and flowering time was earlier for plants grown at a constant 25 or 30C than at 20C. A greenhouse environment with a 16-hour photoperiod and moderately high temperature (25C) would be appropriate for production of H. patens.

scholarly journals Environmental Control of Flowering and Growth of Achillea millefolium L. `Summer Pastels'

HortScience ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 364-365 ◽  
Author(s):  
D. Zhang ◽  
A.M. Armitage ◽  
J.M. Affolter ◽  
M.A. Dirr
Keyword(s):  
Environmental Control ◽  
Dry Weight ◽  
High Irradiance ◽  
Achillea Millefolium ◽  
Flower Bud ◽  
Shoot Dry Weight ◽  
Long Day ◽  
Critical Photoperiod ◽  
Flower Bud Formation ◽  
Delayed Flowering

Achillea millefolium `Summer Pastels' is a qualitative long-day plant with a critical photoperiod between 12 and 16 hours at 18C. Plants grown under a 16-hour photoperiod flowered after 27 days, while those under 8 hours remained vegetative. Shoot dry weight was not affected by photoperiod. Low temperature (10C) delayed the time of flower bud formation and anthesis by ≈20 days. Low irradiance (100 μmol·m–2·s–1) delayed flowering and resulted in lower shoot dry weight, while moderate shading (200 μmol·m–2·s–1) did not significantly affect flowering time and growth compared with high irradiance levels (300 μmol·m–2·s–1).

scholarly journals Photoperiodic Response of Peanut Species1

1983 ◽  
Vol 10 (2) ◽  
pp. 59-62 ◽  
Author(s):  
H. T. Stalker ◽  
J. C. Wynne
Keyword(s):  
North Carolina ◽  
Day Treatment ◽  
Photoperiodic Response ◽  
Reproductive Capacity ◽  
Arachis Species ◽  
Short Day ◽  
The North ◽  
Long Day ◽  
Wild Peanut ◽  
Short Days

Abstract Many Arachis species collections do not produce pegs in North Carolina even though they flower profusely. To investigate reasons for the failure of fruiting, nine wild peanut species of section Arachis and three A. hypogaea cultivars representing spanish, valencia and virginia types were evaluated for response to short and long-day treatments in the North Carolina State Phytotron Unit of the Southeastern Environmental Laboratories. The objective of this investigation was to determine the flowering and fruiting responses of Arachis species to short and long-day photoperiods. Plant collections grown under a 9-hour short-day treatment were generally less vigorous, but produced more pegs than corresponding plants grown in long-day treatments which were produced by 9 hours of light plus a 3-hour interruption of the dark period. Annual species produced significantly more flowers and pegs than perennial species during both long and short days. The total number of flowers produced ranged from 0 during short days for A. correntina to more than 300 for A. cardenasii in long-day treatments. Only one plant of each species A. chacoense and A. villosa, and no plants of A. correntina, flowered in short days. Total numbers of pegs produced in short-day treatments were generally greater than in long-day treatments and the ratio of total number of pegs/total number of flowers was consistently greater during short-day treatments. A general trend was observed for more flowers produced in long-day treatments, but more pegs produced in short days. This study indicated that photoperiod can be manipulated to increase the seed set of some species and the success rate of obtaining certain interspecific hybrids. Furthermore, introgression from wild to cultivated species may possibly alter the reproductive capacity of A. hypogaea to photoperiod.

scholarly journals Incident Irradiance and Cupric Hydroxide Container Treatment Effects on Early Growth and Development of Container-grown Pawpaw Seedlings

2002 ◽  
Vol 127 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Kirk W. Pomper ◽  
Desmond R. Layne ◽  
Snake C. Jones
Keyword(s):  
Leaf Area ◽  
Growth And Development ◽  
Red Light ◽  
Leaf Size ◽  
Dry Weight ◽  
Leaf Number ◽  
The North ◽  
Landscape Plant ◽  
Total Plant ◽  
Cupric Hydroxide

The North American pawpaw [Asimina triloba (L.) Dunal] has great potential as a fruit crop or as a landscape plant. The influence of incident irradiance on pawpaw seedling growth and development in containers was examined in the greenhouse and outdoors. Root spiraling can be a problem for container-grown pawpaw seedlings; therefore, the influence of paint containing cupric hydroxide [Cu(OH)2] at 100 g·L-1 applied to the interior of containers on plant growth was also examined in a greenhouse environment. In pawpaw seedlings grown outdoors for 11 weeks, low to moderate shading levels of 28%, 51%, or 81% increased leaf number, total leaf area, and total plant dry weight (DW) compared to nonshaded seedlings. A shading level of 81% decreased the root to shoot ratio by half compared to nonshaded plants. Shading of 98% reduced leaf number, leaf size, and shoot, root, and total plant DW. Shading increased leaf chlorophyll a and b concentrations for pawpaw seedlings grown outdoors, while it decreased average specific leaf DW (mg·cm-2). In a separate greenhouse experiment, pawpaw seedlings subjected to shade treatments of 0%, 33%, 56%, 81%, or 98% did not respond as greatly to shading as plants grown outdoors. Greenhouse-grown plants had greater total and average leaf area under 33% or 56% shading than nonshaded plants; however, shading >56% reduced root, shoot, and total plant DW. Total shoot DW was greater in greenhouse grown plants with 33% shading compared to nonshaded plants. Pawpaw seedlings in control and most shade treatments (33% to 81%) in the greenhouse environment had more leaves and greater leaf area, as well as larger shoot, root, and total plant DW than seedlings in similar treatments grown outdoors. The greenhouse environment had a 10% lower irradiance, a 60% lower ultraviolet irradiance, and a significantly higher (1.23 vs. 1.20) red to far-red light ratio than the outdoors environment. Treatment of container interiors with Cu(OH)2 decreased total and lateral root DW in nonshaded seedlings, and it adversely affected plant quality by causing a yellowing of leaves and reduction of chlorophyll levels by the end of the experiment in shaded plants. Growth characteristics of pawpaw seedlings were positively influenced by low to moderate shading (28% or 51%) outdoors and low shading (33%) in the greenhouse. Seedlings did not benefit from application of Cu(OH)2 to containers at the concentration used in this study. Commercial nurseries can further improve production of pawpaw seedlings using low to moderate shading outdoors.

scholarly journals INFLUENCE OF PHOTOPERIOD AND GIBBERELLIC ACID ON GROWTH AND FLOWERING OF CRASPEDIA UNIFLORA.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1092a-1092
Author(s):  
David C. Annis ◽  
Terri Starman
Keyword(s):  
Gibberellic Acid ◽  
Day Treatment ◽  
Foliar Spray ◽  
Dry Weight ◽  
Stem Length ◽  
Cut Flower ◽  
Cut Flowers ◽  
Fresh Weight ◽  
Flower Production ◽  
Long Day

Flowers of Craspedi a uniflora (Billy Buttons), a New Zealand annual plant, have been introduced recently into the U.S.A. florist market. Craspedia is relatively unknown in the U.S.A., but is beginning to be utilized by florists as a cut flower and has potential for specialty cut flower production. Craspedia uniflora cut flowers were grown from seed in an inflated, double-layer, polyethylene greenhouse. Short day (SD) and long day (LD) photoperiod treatments were applied by daylength reduction via black cloth and night interruption lighting, respectively. Treatments began 10 weeks after sowing (15 leaf stage) and continued until harvest. Gibberellic acid was applied as a single foliar spray to runoff at 0 and 500 mg·liter-1 at initiation of photoperiod treatment. Long day treatment reduced days to anthesis, increased flower number, and decreased stem length and plant fresh weight. Gibberellic acid (500 mg·liter-1) increased foliage height under both photo period treatments and increased plant dry weight under LD but reduced dry weight under SD treatment. Flower fresh weight, diameter and bud number were not affected by treatment.

Effect of Irradiance Level and Paclobutrazol on Reducation of Leaf Damage in Begonia × cheimantha

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 446d-446
Author(s):  
Beyounghan Yoon ◽  
Harvey J. Lang
Keyword(s):  
Day Treatment ◽  
Leaf Damage ◽  
Growth Retardants ◽  
Damage Development ◽  
Long Day ◽  
Leaf Chlorosis ◽  
Shade Cloth ◽  
Growing Conditions ◽  
Reduced Light ◽  
Shade Plants

Begonia × cheimantha (Christmas or Lorraine begonia) is a popular holiday crop in Europe, with certain cultivars having outstanding postharvest characteristics. Its commercial production in the southern United States has been limited by the occurrence of mottled leaf chlorosis and necrosis, apparently due to environmental stress. In this study, B. × cheimantha `Emma' was grown in the fall in a glass greenhouse at College Station, Texas, under either 0%, 60%, or 87% polyethylene shade cloth. Leaf chlorosis and necrosis was very severe on plants grown in full sun (≈650 mol·m–2·s–1), with slight chlorosis on plants under 60% shade. Plants under full sun, however, were more compact, flowered earlier, and had shorter peduncles with more flowers than those grown under shade. Reducing the vegetative long-day treatment period from 7 to 4 weeks had no effect on leaf damage development. Plants treated with paclobutrazol were shorter and had less leaf damage than untreated plants. Leaves of treated plants had a relatively higher concentration of soluble protein, chlorophyll, and enhanced activities of ascorbate peroxidase (AsA), dehydroascorbate (DHA) reductase, and monodehydro-ascorbate (MDHA) reductase than untreated plants. For Texas growing conditions, these preliminary studies indicate that B. × cheimantha should be grown under reduced light intensities, with excessive height and leaf damage being controlled with growth retardants such as paclobutrazol.

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