scholarly journals Growth and Development of Petunia × hybrids as a Function of Temperature and Irradiance

1991 ◽  
Vol 116 (2) ◽  
pp. 232-237 ◽  
Author(s):  
M.P. Kaczperski ◽  
W. H. Carlson ◽  
M.G. Karlsson
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Average Length ◽  
Quadratic Function ◽  
Internode Length ◽  
Photon Flux ◽  
Optimum Temperature ◽  
Photosynthetic Photon Flux ◽  
Average Temperature ◽  
Lateral Shoots

Petunia × hybrids `Snow Cloud' plants were grown under 25 temperature combinations ranging from 10 to 30C and at photosynthetic photon flux levels of 100 or 200 μmol·s-1·m-2 (6.5 and 13 mol·day-1·m-2, respectively). Days to flower-was a quadratic function of average temperature, with 25C being the optimum temperature for minimal tire-e to flower at 200 μmol·s-1·m-2. Plant height increased “linearly and average internode length increased quadratically as day temperature increased. The number of lateral shoots decreased quadratically as average temperature increased, and the average length of each shoot decreased quadratically as day temperature increased.

scholarly journals EFFECTS OF MICROPROPAGATION TECHNIQUES ON GROWTH. AND DEVELOPMENT OF MINIATURE ROSES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1138a-1138
Author(s):  
C.Y. Chu ◽  
S.L. Knight
Keyword(s):  
Growth And Development ◽  
Low Cost ◽  
High Potential ◽  
Internode Length ◽  
Photon Flux ◽  
Initial Growth ◽  
Multiplication Rate ◽  
Stem Tissue ◽  
Photosynthetic Photon Flux ◽  
High Quality

An efficient micropropagation system is being investigated to produce low cost and high quality miniature rose plants. Dormant literal buds of miniature roses were cultured on media containing MS, 30 g·l-1 sucrose, 8 g·l-1, and 25 combinations of NAA and BA. Initial explant growth was achieved on a medium containing NAA at 0.001-0.01 ppm and BA at 0.1 ppm. The highest multiplication rate was achieved when explants were subcultured on a medium containing MS, NAA at 0.01 ppm, BA at 2 ppm, and sucrose at 30 g·l-1. Growth was enhanced after culturing when dormant buds had more parental stem tissue. In addition, explants from the lowest two nodes with the shortest internode length exhibited the poorest growth. The higher the photosynthetic photon flux (PPF) (5 to 40 μmol·s-1m-2), the more quickly explants grew and aged. The most optimal PPF for initial growth was 20 μmol·s-1m-2. Subculture microcuttings of one cm or more in length grew vigorously one month after cuttings were dipped in 1000 ppm IBA and placed on a mist bench. Our results indicate that micropropagation of miniature roses has high potential for use in commercial industry.

Control of Growth and Flowering in Two Western Australian Species of Pimelea

1992 ◽  
Vol 40 (3) ◽  
pp. 377 ◽  
Author(s):  
RW King ◽  
IA Dawson ◽  
SS Speer
Keyword(s):  
Plant Height ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Average Temperature ◽  
Australian Species ◽  
Floral Primordia ◽  
Western Australian ◽  
Cool Conditions

Pimelea ferruginea and P. rosea both show an obligate requirement for exposure to mean temperatures below 15°C for more than 5 weeks for induction of flowering. Subsequently, floral primordia develop slowly in these cool conditions or rapidly if the average temperature is raised to 21°C. Plants held at 21°C or warmer remained vegetative for over 1 year. P. rosea was found to be daylength neutral, whereas flowering of P. ferruginea was enhanced, slightly, by a short day photoperiod of 10 h. Plant height was greater for both species in long days. Benzylaminopurine (BA) was effective for increasing branching. Gibberellin A3 (GA3) and paclobutrazol were effective in controlling plant height in P. ferruginea. Flower life was not altered by application of silver thiosulfate and BA, and was greatest when plants were grown in high photosynthetic photon flux density and at lower temperatures (15/ 10°C v. 24/19°C).

scholarly journals Controlling Height with Temperature

1998 ◽  
Vol 8 (4) ◽  
pp. 535-539 ◽  
Author(s):  
Robert Berghage
Keyword(s):  
Plant Height ◽  
Production Systems ◽  
Formation Rate ◽  
Internode Length ◽  
Temperature Management ◽  
Night Temperature ◽  
Greenhouse Production ◽  
Node Number ◽  
Height Control ◽  
Average Temperature

Temperature management has emerged as an important tool for plant height control in greenhouse production systems. This is particularly important in vegetable transplant production where chemical controls for plant height are limited or not legal. Plant height is a function of the number of nodes and the length of each internode, and both are strongly influenced by greenhouse temperatures. Node number, or formation rate, is primarily a function of the average greenhouse temperature, increasing as the average temperature increases. Internode length is strongly influenced by the relationship between the day and night temperature, commonly referred to as DIF (day temperature - night temperature). As DIF increases, so does internode length in most plant species studied. Although the nature and magnitude of temperature effects vary with species, cultivar, and environmental conditions, these two basic responses can be used to modify transplant growth. Although data are limited, controlling transplant height with temperature does not appear to adversely influence plant establishment or subsequent yield.

SUPPLEMENTARY LIGHTING FOR RESEARCH GREENHOUSES

1984 ◽  
Vol 64 (3) ◽  
pp. 773-779 ◽  
Author(s):  
E. ANN CLARK ◽  
M. D. DEVINE
Keyword(s):  
High Pressure ◽  
Plant Growth ◽  
Flux Density ◽  
Growth And Development ◽  
Photosynthetic Photon Flux Density ◽  
Metal Halide ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Supplementary Lighting

The growth and development of six plant species were measured under a standardized photosynthetic photon flux density (PPFD) supplied by fluorescent, metal halide, or high-pressure sodium lamps. Overall, plant growth and seed yield were in the order of high-pressure sodium > metal halide > fluorescent. Although the units tested were unable to supply a uniform, high flux density, acceptable plant growth was achieved under the compromise arrangements used.Key words: Fluorescent, metal halide, high pressure sodium, supplementary lighting

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