scholarly journals RESPONSE SURFACE REPRESENTATION OF ROSE (ROSA HYBRIDA L.) GROWTH CHARACTERISTICS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1138d-1138
Author(s):  
Douglas A. Hopper ◽  
P. Allen Hammer
Keyword(s):  
Rapid Development ◽  
Dry Weight ◽  
Developmental Time ◽  
Response Surfaces ◽  
Growth Characteristics ◽  
Stem Length ◽  
Quadratic Model ◽  
Photon Flux ◽  
Flower Bud ◽  
Node Number

Day (DT) and night temperature (NT), and irradiation (photosynthetic photon flux-PPF) treatment combinations were run from a rotatable central composite design. At flowering, response surfaces were plotted for `Royalty' rose for plant growth characteristics: node number, stem diameter, stem length, and dry weight of stem, leaves, flower bud, and total shoot. Overall development was recorded from pinch until visible bud, first bud color, and flowering. All characteristics except node number and stem length were significant (P=0.05) for a full quadratic model having ten estimated coefficients. Greatest dry weights were predicted at flowering for the lowest DT (15C) and NT (12C) combination, and required the longest time for development. Conversely, most rapid development and least dry weight accumulated for high DT (25C) and NT (22C). Thus, a compromise exists between rapid development and quality of the flowering stem. As PPF increased from 50 to 300 μmol m-2s-1, predictions for dry weights increased while developmental time decreased.

scholarly journals 511 PB 283 SEASONAL COMPARISONS OF THREE ROSE (ROSA HYBRIDA L.) CULTIVARS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 504f-504
Author(s):  
Virginia S. Story ◽  
Douglas A. Hopper ◽  
Troy T. Meinke
Keyword(s):  
Analysis Of Variance ◽  
Rosa Hybrida ◽  
Stem Diameter ◽  
Stem Length ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Flower Bud ◽  
Node Number ◽  
Flower Stem ◽  
Valentine's Day

Two-year-old Rosa hybrida L. `Royalty', `Emblem', and `Samantha' plants were pinched 20 Oct. and 28 Dec. 1992 for Christmas and Valentine's Day crops. At 10 and 25 days after pinch, and at flowering, 5 shoots from each bench location were destructively sampled for leaf (node) number, stem diameter, stem length, and fresh and dry weights of stem, leaves, and flower bud. Time to visible bud, to color, and to flower from pinch were also recorded. Results were tabulated; an analysis of variance showed that the three rose cultivars produced flowers which were not significantly different within crops but were different between seasonal crops. The Christmas `Royalty' crop produced more flowers (but also more blind shoots) than did the Valentine's Day crop. Days to flower, stem diameters, and stem lengths were similar within and between crops for all cultivars. Total fresh and dry weights for all three cultivars tended to be greater for the Valentine's Day crop than for the Christmas crop. The seasonal photosynthetic photon flux (PPF) variation may account for these differences.

scholarly journals Response of Oxypetalum caeruleum to Irradiance, Temperature, and Photoperiod

1990 ◽  
Vol 115 (6) ◽  
pp. 910-914 ◽  
Author(s):  
A.M. Armitage ◽  
N.G. Seager ◽  
I.J. Warrington ◽  
D.H. Greer ◽  
J. Reyngoud
Keyword(s):  
Stem Elongation ◽  
Net Photosynthesis ◽  
Stem Length ◽  
Photon Flux ◽  
Vase Life ◽  
Photosynthetic Photon Flux ◽  
Node Number ◽  
Stem Strength ◽  
Flower Abortion ◽  
Reduced Time

Incremental increases in temperature from 14 to 22 to 30C resulted in linear increases in stem length and node number and decreases in stem diameter and stem strength of Oxypetalum caeruleum (D. Don.) Decne. Higher temperatures also resulted in additional flower abortion, reduced time to flowering, and fewer flowering stems per inflorescence. Reduction in the photosynthetic photon flux (PPF) from 695 to 315 μmol·s-1·m-2 had similar effects as increasing the temperature on vegetative characteristics, but had little effect on reproductive ones. The rate of stem elongation was greatest at low PPF for all temperatures and at high temperature for all PPF treatments. Net photosynthesis rose between 14 and 22C and declined at 30C for all PPF treatments. Long photoperiods (12 or 14 hours) resulted in longer internodes, longer stems, and more flowers per cyme than short photoperiods (8 or 10 hours), but photoperiod had little effect on flowering time. Treatments to reduce latex coagulant and silver thiosulfate treatments had no significant effect on vase life.

scholarly journals 786 PB 436 COMPARING ROSE RESPONSES TO VARIOUS ENVIRONMENTS USING THE ROSESIM COMPUTER GROWTH MODEL

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 545e-545
Author(s):  
Douglas A. Hopper ◽  
Troy T. Meinke ◽  
Virginia S. Store
Keyword(s):  
Management Strategies ◽  
Leaf Size ◽  
Dry Weight ◽  
Photon Flux ◽  
Computer Simulation Model ◽  
Flower Bud ◽  
Crop Development ◽  
Valentine's Day ◽  
Flower Quality ◽  
Constant Growth

The computer simulation model ROSESIM is based on `Royalty' rose (Rosa hybrida L.) growth response to 15 unique treatment combinations of photosynthetic photon flux (PPF), day temperature (DT), and night temperature (NT) under constant growth chamber conditions. Environmental factors are assumed constant over an entire day, but set points may vary over the duration of the crop. Anticipated values for factors may be read from an ASCII file, allowing a variety of strategies to be modeled and compared. A Valentine's Day crop senario compared 2 management strategies for crop development time and flower quality: [1] constant 24/17.1 DT/NT for the entire crop, or [2] 15 days warm 30/20C DT/NT to promote bud break, 10 days 20/15C DT/NT to promote stem caliper and leaf size, 10 days 25/18C DT/NT to promote bud development, and remaining time to flower 20/15C DT/NT to enhance flower size and color. PPF was increased gradually over crop time as would occur naturally for Dec. to Feb. Strategy [2] had longer stems (63 vs. 50 cm), similar stem and leaf dry weights, but less flower bud dry weight (1.0 vs. 1.6 g), while flowering 2 days earlier (41 vs. 43 days after pinch). c:\pm4\ash94h.pm 4

scholarly journals Analysis of Heat Tolerance in New Guinea Impatiens (Impatiens hawkeri) Utilizing Diallel Analysis

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 499B-499
Author(s):  
Kerry M. Strope ◽  
Mark S. Strefeler
Keyword(s):  
Heat Tolerance ◽  
Selection Index ◽  
Dry Weight ◽  
Leaf Color ◽  
Flower Bud ◽  
Branch Number ◽  
Node Number ◽  
Combining Abilities ◽  
Flower Diameter ◽  
Heat Tolerant

Four heat-tolerant (`Celebration Cherry Red', `Celebration Rose', `Lasting Impressions Shadow', and `Paradise Moorea') and three non-heat-tolerant (`Lasting Impressions Twilight', `Danziger Blues', and `Pure Beauty Prepona') cultivars were identified using a Weighted Base Selection Index. These cultivars were used as parents in a full diallel crossing block with reciprocals and selfs. Progeny from five parents (25 crosses) were evaluated for heat tolerance. Four floral (fl ower number, flower diameter, flower bud number, and floral dry weight) and five vegetative characteristics (visual rating, leaf size rating, vegetative dry weight, branch number, and node number) were evaluated with emphasis placed on continued flowering under long-term heat stress. In addition, progeny from all seven parents (49 crosses) were evaluated for inheritance of adaxial leaf color, abaxial leaf color, vein color, and flower color. Significant differences were found in each data category (P < 0.001) with the exception of node number, which was not significant. Flower number varied from 0 to 2, flower diameter varied from 0 to 41 mm, floral dry weight varied from 14 to 105 mg, bud number varied from 0 to 12, branch number varied from 5 to 15, and vegetative dry weight varied from 220 to 607 mg. General and specific combining abilities of the parents were evaluated as was heritability. It was found that the four heat-tolerant cultivars had higher general combining abilities. Heat tolerance has low heritability and is controlled by many genes.

scholarly journals Growth inhibition of Hydrilla verticillata by freshwater fungi

2021 ◽  
Vol 22 (7) ◽  
Author(s):  
Triadiati Triadiati ◽  
Nampiah Sukarno ◽  
IRMA SITI RAHMAH
Keyword(s):  
Growth Inhibition ◽  
Hydrilla Verticillata ◽  
Dry Weight ◽  
Growth Characteristics ◽  
Leaf Damage ◽  
Leaf Number ◽  
Stem Length ◽  
Freshwater Fungi ◽  
Fungal Treatment ◽  
Freshwater Fungus

Abstract. Triadiati T, Sukarno N, Rahmah IS. 2021. Growth inhibition of Hydrilla verticillata by freshwater fungi. Biodiversitas 22: 2876-2882. The uncontrolled growth of hydrilla (Hydrilla verticillata (L.f.) Royle) in Mekarsari Fruit Garden, Bogor causes various losses. A Freshwater fungus is one of the alternatives to control hydrilla growth. Therefore, the study aimed to investigate the damage and growth inhibition of hydrilla using freshwater fungi. Freshwater fungi were isolated from Lake Mekarsari Fruit Garden. Hydrilla growth characteristics observed were stem length, stem nodus number, number of healthy leaves, leaf number, leaf damage, wet and dry weight. The results showed that a total of seven isolates of freshwater fungi were obtained from Lake Mekarsari Fruit Garden. Two species, i.e. Myrothecium sp. and Stachybotrys sp. were selected to control hydrilla growth. Fungal treatment reduced the stem length and leaf number of hydrilla. The combination of both fungal isolates showed less leaf damage than Myrothecium sp. The damage of hydrilla leaves by Myrothecium sp. and Stachybotrys sp. were 98.07% and 78.71%, respectively.

scholarly journals Light Intensity Affects Growth, Photosynthetic Capability, and Total Flavonoid Accumulation of Anoectochilus Plants

HortScience ◽  
2010 ◽  
Vol 45 (6) ◽  
pp. 863-867 ◽  
Author(s):  
Zengqiang Ma ◽  
Shishang Li ◽  
Meijun Zhang ◽  
Shihao Jiang ◽  
Yulan Xiao
Keyword(s):  
Light Intensity ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Total Flavonoid ◽  
Stem Length ◽  
Photon Flux ◽  
Low Light ◽  
Four Levels ◽  
Anoectochilus Formosanus ◽  
Flavonoid Accumulation

Anoectochilus formosanus, a medicinal plant used to treat hypertension, lung disease, and liver disease, was grown to maximize biomass and secondary metabolite production in a controlled environment under four levels of photosynthetic photon flux (PPF), namely, 10, 30, 60, or 90 μmol·m−2·s−1, that is L10, L30, L60, and L90 treatments, respectively. On Day 45, all growth values were greatest for the L30 plants. Dry weight was lowest for the L10 plants. Leaf area, stem length, and fresh weight were lowest for the L90 plants. The chlorophyll concentration was highest in the L10 treatment and decreased with increasing PPF. Electron transport ratios of leaves were highest in the L30 treatment and lowest in the L90 for the second leaf (counted down from the apex) and in the L10 for the third leaf. An increase in light intensity from 10 to 60 μmol·m−2·s−1 increased the superoxide dismutase activity and was associated with an increase in the total flavonoid concentration. The total flavonoid concentration (mg·g−1 DW) was greatest in the L60 and lowest in the L90. However, the total flavonoid content (mg/plant) was highest in the L30 plants as a result of great biomass. The results indicated that A. formosanus is a typical shade plant suitable to grow under low light intensity at PPF of 30 to 50 μmol·m−2·s−1 for both growth and production of total flavonoid. A light intensity of 90 μmol·m−2·s−1 induced stress on plant growth and reduced photosynthetic capability and the flavonoid accumulation.

scholarly journals Growth Characteristics and Root Calcium Absorption of Watermelon Seedlings as Influenced by the Fungicides Captan and Thiram

1994 ◽  
Vol 119 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Aimin Liu ◽  
Joyce G. Latimer ◽  
Robert E. Wilkinson
Keyword(s):  
Calcium Absorption ◽  
Citrullus Lanatus ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Growth Characteristics ◽  
Acidic Soil ◽  
Stem Length ◽  
Growth Stages ◽  
Tetramethylthiuram Disulfide ◽  
Root Curvature

The influence of two fungicides—captan and thiram—on growth and 45Ca absorption by roots of `Starbrite' watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] seedlings was investigated. Unilateral application of Ca+2 and Al in agar induced curvature in roots from untreated and pretreated seeds. In untreated seeds, PCMBS inhibited Ca+2- and Al-induced root curvature by 82% and 92%, respectively. In commercially pretreated seeds (captan + thiram), PCMBS inhibited Ca+2- but not Al-induced root curvature. Captan or thiram also inhibited Ca+2- or Al-induced root curvature, and the effects of captan and thiram on root curvature were additive. Serial concentration (0, 0.01, 0.1, 1, 10, or 100 mg·liter-1) tests indicated that captan inhibited 45Ca absorption the most at 100 mg·liter-1, whereas thiram inhibited 45Ca absorption the most at 0.01 mg·liter-1. The effects of captan and thiram on 45Ca absorption were statistically additive. Thiram seemed to influence Ca+2 uptake by affecting exofacial sulfhydryl groups (a mode of action similar to that of PCMBS). DTT reversed the inhibitory effect of thiram on 45Ca absorption by 34% but did not reverse the effect of captan. A field test showed that acidic soil (pH 4.55) reduced leaf number; leaf, stem, shoot, and whole-plant dry weights; and stem length of 15-day-old seedlings. Although there was no difference in root dry weights or root: shoot ratios of plants from pretreated and untreated seeds planted in soil at pH 6.26, planting commercially pretreated seeds in acidic soil produced plants with greater root dry weights and root: shoot dry weight ratios than those from untreated seeds. Seedlings showed a greater response to seed treatment in early growth stages. Captan and thiram may have influenced growth characteristics by inhibiting Al uptake of seedlings planted in acidic soil. To our knowledge, this is the first report on the influence of the fungicides captan and thiram on mineral ion uptake in roots. Chemical names used: p-Chloromercuribenzenesulfonic acid (PCMBS), dithiothreitol (DTT), N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide (captan), tetramethylthiuram disulfide (thiram).

scholarly journals Enhancement of Growth and Development of Tomato Seedlings by Extending the Light Period Each Day

HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 370-373 ◽  
Author(s):  
Hiromi Toida ◽  
Katsumi Ohyama ◽  
Yoshitaka Omura ◽  
Toyoki Kozai
Keyword(s):  
Growth And Development ◽  
Dark Period ◽  
Electric Energy ◽  
Dry Weight ◽  
Light Period ◽  
Photon Flux ◽  
Flower Bud ◽  
Electric Energy Consumption ◽  
Tomato Seedlings ◽  
Bud Initiation

The light and dark periods can be easily controlled by the use of artificial lighting. To understand the effects of alternation of light and dark periods on plant growth and development, we studied the growth and development of tomato (`Momotaro') seedlings under nonperiodic alternation of light and dark periods. Tomato seedlings grown under two nonperiodic alternation treatments of NF (NF-1 and NF-2) were compared with seedlings grown under a periodic alternation treatment (P treatment) with 12-hour light and dark periods. In all treatments, photosynthetic photon flux (PPF) during the light period was maintained at 280 μmol·m-2·s-1; the sum of each light period and the following dark period was 24 hours; and each of the integrated light and dark periods was 132 hours during 11 days of the experiment. In NF-1, the initial light and dark periods were 7 and 17 hours, respectively, and the light period was extended 1 hour per day, while in NF-2, they were initially 17 and 7 hours, respectively, and the light period was shortened 1 hour per day. At the end of the experiment, dry weight per seedling was greater and flower-bud initiation of the first flower truss was earlier in NF-1 than in NF-2 and P, even though the integrated PPF during the experiment was the same in all treatments. These results demonstrate that growth and development of tomato seedlings can be enhanced without any increase in electric energy consumption for lighting by gradually extending the light period or shortening the dark period.

scholarly journals A Simulation Model of Rosa hybrida Growth Response to Constant Irradiance and Day and Night Temperatures

1994 ◽  
Vol 119 (5) ◽  
pp. 903-914 ◽  
Author(s):  
Douglas A. Hopper ◽  
P. Allen Hammer ◽  
James R. Wilson
Keyword(s):  
Plant Growth ◽  
Simulation Model ◽  
Growth Response ◽  
Growth Characteristics ◽  
Rosa Hybrida ◽  
Stem Length ◽  
Photon Flux ◽  
Growth Responses ◽  
Wide Range ◽  
Plant Growth Characteristics

This paper details the development and verification of ROSESIM, a computer simulation model of the growth of `Royalty' roses (Rosa hybrida L.) based on experimentally observed growth responses from pinch until flowering under 15 combinations of constant photosynthetic photon flux (PPF), day temperature (DT), and night temperature (NT). Selected according to a rotatable central composite design, these treatment combinations represent commercial greenhouse conditions during the winter and spring in the midwestern United States; each selected condition was maintained in an environmental growth chamber having 12-hour photoperiods. ROSESIM incorporates regression models of four flower development characteristics (days from pinch to visible bud, first color, sepal reflex, and flowering) that are full quadratic polynomials in PPF, DT, and NT. ROSESIM also incorporates mathematical models of nine plant growth characteristics (stem length and the following fresh and dry weights: stem, leaf, flower, and total) based on data recorded every 10 days and at flowering. At each design point, a cubic regression in time (days from pinch) estimated the plant growth characteristics on intermediate days; then difference equations were developed to predict the resulting daily growth increments as third-degree polynomial functions of days from pinch, PPF, DT, and NT. ROSESIM was verified by plotting against time each simulated plant growth characteristic and the associated experimental observations for the eight factorial design points defining the region of interest. Moreover, one-way analysis of variance procedures were applied to the differences between ROSESIM predictions and the corresponding observed means for all 15 treatment combinations. At 20 days from pinch, significant differences (P < 0.05) were observed for all nine plant growth characteristics. At 30 and 40 days from pinch, only flower fresh and dry weights yielded significant differences; at flowering, none of the 13 selected responses yielded significant differences. These graphical and statistical comparisons provide good evidence of ROSESIM's ability to predict the growth response of `Royalty' roses over a wide range of constant environmental conditions.

scholarly journals Effects of Light Quality on Growth and Quality of in Vitro Plantlets during Low-temperature Storage

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 809C-809
Author(s):  
Chieri Kubota ◽  
Nihal C. Rajapakse ◽  
Roy E. Young
Keyword(s):  
Blue Light ◽  
Chlorophyll Concentration ◽  
Dry Weight ◽  
Stem Length ◽  
Photon Flux ◽  
Spectral Quality ◽  
Low Temperature Storage ◽  
Light Spectra ◽  
Plantlet Quality

Broccoli `Green Duke' plantlets, which were ready for transplanting after 2 weeks of photoautotrophic (sugar-free) culture under the conditions of 1100 μmol·mol–1 CO2 (outside the vessel), 22±4C air temperature, and 140 μmol·m–2·s–1 photosynthetic photon flux (PPF), were stored for 6 weeks at 5C in darkness or in white, red, or blue light at 2 μmol·m–2·s–1 PPF. Photoperiod was set at 24 h/day during storage. Spectral quality significantly affected plantlet quality: stem length was longer and chlorophyll concentration of leaves was lower in red or in blue light than in white light or in darkness after 6 weeks in storage. Regardless of the spectral quality, light in storage maintained plantlet dry weight at a level comparable to that before storage, while dry weight was reduced significantly in dark-stored plantlets. Spectral quality did not significantly affect the photosynthetic and regrowth potential of plantlets. All plantlets stored in light, regardless of light spectra, showed comparably high photosynthetic ability after storage and had similar dry weight, number of leaves, and stem length after 9 weeks of transplanting to the greenhouse under natural light.

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