scholarly journals Calibration Coefficients Added to ROSESIM Improve Predictions of Growth in Greenhouse Conditions

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 654d-654
Author(s):  
Douglas A. Hopper ◽  
Kevin T. Cifelli
Keyword(s):  
Quadratic Model ◽  
Photon Flux ◽  
Controlled Environment ◽  
Initial Growth ◽  
Growth Responses ◽  
Model Based ◽  
Growth Equations ◽  
Actual Growth ◽  
Constant Growth ◽  
Calibration Coefficients

Growth predictions derived from data collected in controlled-environment chambers would be expected to differ from growth responses observed in variable greenhouse conditions. ROSESIM was developed as a dynamic plant growth model based on `Royalty' rose (Rosa hybrida L.) response to 15 unique treatment combinations of photosynthetic photon flux (PPF), day temperature (DT), and night temperature (NT) under constant growth chamber conditions. Regression coefficients for growth equations are read from an external ASCII file, thus permitting coefficients up to a full quadratic model form. Calibration coefficients (CC) were added to ROSESIM to enable predictions to be altered proportionally to permit improved prediction of specific growth characteristics. Numerator and denominator values for CC are adjustable for the first 10 days (initial) growth equations, subsequent growth until anthesis equations, and for the prediction of anthesis. Validation studies were used to set CC values; this enables the model based on growth in controlled environment chambers to be systematically calibrated on site to fit actual growth measured at a specific greenhouse location.

scholarly journals Temperature Effects on Growth of Impatiens Plug Seedlings in Controlled Environments

1992 ◽  
Vol 117 (2) ◽  
pp. 209-215 ◽  
Author(s):  
David R. Dreesen ◽  
Robert W. Langhans
Keyword(s):  
Leaf Area ◽  
Growth Period ◽  
Dry Weight ◽  
Photon Flux ◽  
Initial Growth ◽  
Growth Responses ◽  
Shoot Height ◽  
Seedling Age ◽  
Shoot Dry Weight ◽  
Air Temperatures

The objective of this study was to determine the dry weight, height, and leaf area growth responses of impatiens (Impatiens walerana Hook. f.) plug seedlings to air temperatures ranging from 18 to 29C. The conditions maintained in the controlled-environment growth rooms (CEGR) were ambient C02 levels, 24-h lighting, and photosynthetic photon flux (PPF) ranging from ≈215; to 335 μmol·m-2·s-1. Mean daily temperatures of the plug medium ranged from 19.6 to 27.7C. At the higher PPF level, shoot dry weight decreased at plug medium temperatures (PMT) > 25C; at lower PPF levels (<300 μmol·m-2·s-1), shoot dry weight continued to increase with PMT > 25C. The mean relative growth rate (MRGR) of shoot dry weight was positively correlated with PMT during the initial growth period (up to 14 days from sowing) and was negatively correlated thereafter. The maximum MRGR was predicted to occur at 11.7 days from sowing for a PMT of 19.6C, at 10.8 days for a PMT of 21.6C, and at 9.7 days for a PMT of 23.6C. Linear regression coefficients of shoot height as a function of PMT were substantially higher for seedlings grown at lower PPF than those for seedlings from the highest PPF level. Seedling leaf area consistently increased with increasing temperature. Net assimilation rate (NAR) decreased with increasing seedling age NAR increased with increasing PPF. A decrease in NAR was apparent at 29C relative to values at the lower temperatures. Leaf area ratio (LAR) declined with increasing seedling age and PPF; a quadratic relationship of LAR as a function of PMT indicates a minimum LAR at 22.5C. The seedlings grown at 29C were excessively tall, had thin succulent leaves, and were judged unacceptable for shipping and transplanting. Maximum quality indices (i.e., dry weight per height) were found at PMT of 24.3 to 25.OC for 10- to 14-day-old seedlings and at PMT of 23.0 to 24.OC for 16- to 20-day-old seedlings.

scholarly journals 264 Richards Function Applied to a Daily Additive and Iterative Approach to Model Rose Plant Stem Length Growth

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 436F-437
Author(s):  
Douglas A. Hopper
Keyword(s):  
Dynamic Change ◽  
Stem Length ◽  
Quadratic Model ◽  
Photon Flux ◽  
Daily Growth ◽  
Richards Function ◽  
Plant Stem ◽  
Plant Stem Length ◽  
Parameter Values ◽  
Constant Growth

Height data were collected three times weekly between pinch and flowering to represent `Royalty' rose (Rosa hybrida L.) response to 15 unique treatment combinations of irradiation as photosynthetic photon flux (PPF: 50 to 300 μmol·m-2·s-1), day temperature (DT: 12 to 22 °C), and night temperature (NT: 15 to 25 °C) under constant growth chamber conditions. Combinations were determined according to the rotatable central composite design. A previous full quadratic model approach was compared with a revised approach using a nonlinear Richards function derivative form. This allowed a dynamic change of parameter values for each daily growth iteration by computer. The Richards function assumes nonconstant daily growth rates are proportional to current size; Euler integration enabled additive accumulation of these values. Ratios of the growth constant (k) to the theoretical catabolic constant (m = v+1) caused flexible changes in the growth curve, which were compared with the previous quadratic approach.

scholarly journals ROSESIM Restructured To Accept Full Quadratic Polynomial Coefficients and Daily Step Input

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 866D-866
Author(s):  
Douglas A. Hopper ◽  
Kevin Cifelli
Keyword(s):  
Plant Growth ◽  
Quadratic Model ◽  
Photon Flux ◽  
Interactive Simulation ◽  
Linear Quadratic ◽  
Polynomial Coefficients ◽  
Interaction Terms ◽  
User Friendly ◽  
Microsoft Windows ◽  
Constant Growth

An interactive simulation model of plant growth must be flexible to accept specific crop equations from the user. ROSESIM functions as a dynamic plant growth model based on `Royalty' rose (Rosa hybrida L) 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. Coefficients are read from an external ASCII file, thus permitting coefficients from any linear, quadratic, or interaction terms to be input into ROSESIM up to a full quadratic model form. Nonsignificant terms are given a coefficient of zero. ROSESIM has been restructured into Borland C++ object oriented program (OOP) code to execute in the Microsoft Windows 3.1 operating environment. This enables ease of operation in the user friendly graphical user interface (GUI) provided with most IBM personal computers (PC). The user chooses a set of environmental conditions which can be altered after any selected number of days, allowing conditions to be changed and modeled daily for interactive comparison studies.

KINETIC SURFACE ROUGHENING AND MOLECULAR BEAM EPITAXY

Fractals ◽  
1993 ◽  
Vol 01 (04) ◽  
pp. 784-794 ◽  
Author(s):  
S. DAS SARMA
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Coarse Grained ◽  
Solid State Physics ◽  
Growth Phenomenon ◽  
Recent Developments ◽  
Growth Equations ◽  
Universality Classes ◽  
Actual Growth

We review recent developments in our understanding of Molecular Beam Epitaxy as a kinetically rough growth phenomenon. It is argued that while the most general growth conditions lead to generic growth universality, actual growth conditions allow a complex interplay of several different dynamic universality classes producing rich crossover behavior determined by growth temperature, incident flux rate, and local solid state physics and chemistry of the growing material. Possible coarse-grained continuum growth equations which may be applicable to Molecular Beam Epitaxy are discussed.

scholarly journals A System and Methodology for Measuring Volatile Organic Compounds Produced by Hydroponic Lettuce in a Controlled Environment

1996 ◽  
Vol 121 (3) ◽  
pp. 483-487 ◽  
Author(s):  
Craig S. Charron ◽  
Daniel J. Cantliffe ◽  
Raymond M. Wheeler ◽  
Ara Manukian ◽  
Robert R. Heath
Keyword(s):  
Dark Period ◽  
Photon Flux ◽  
Controlled Environment ◽  
Qualitative And Quantitative Analysis ◽  
Lipoxygenase Pathway ◽  
Qualitative And Quantitative ◽  
Volatile Collection ◽  
Volatile Organic ◽  
Hydroponically Grown ◽  
Leaf Lettuce

A system and methodology were developed for the nondestructive qualitative and quantitative analysis of volatile emissions from hydroponically grown `Waldmann's Green' leaf lettuce (Lactuca sativa L.). Photosynthetic photon flux (PPF), photoperiod, and temperature were automatically controlled and monitored in a growth chamber modified for the collection of plant volatiles. The lipoxygenase pathway products (Z)-3-hexenal, (Z)-3-hexenol, and (Z)-3-hexenyl acetate were emitted by lettuce plants after the transition from the light period to the dark period. The volatile collection system developed in this study enabled measurements of volatiles emitted by intact plants, from planting to harvest, under controlled environmental conditions.

INTERACTION OF TEMPERATURE AND CO2 ENRICHMENT ON SOYBEAN: GROWTH AND DRY MATTER PARTITIONING

1987 ◽  
Vol 67 (1) ◽  
pp. 59-67 ◽  
Author(s):  
NASSER SIONIT ◽  
B. R. STRAIN ◽  
E. P. FLINT
Keyword(s):  
Low Temperature ◽  
Environmental Control ◽  
Weight Ratio ◽  
Controlled Environment ◽  
Plant Responses ◽  
Growth Responses ◽  
Dry Matter Partitioning ◽  
Leaf Weight ◽  
Temperature Regimes ◽  
Increasing Temperature

Projected increases in atmospheric CO2 concentration will affect growth and productivity of many plant species under various environmental conditions. Since these increases in CO2 may also increase mean annual temperatures, it is important to determine how the soybean (Glycine max (L.) Merr.) will respond to changes in temperature regimes associated with atmospheric CO2 enrichment. Morphology and growth responses of the Ransom cultivar, which is adapted to a southern U.S.A. climate, to day/night temperature regimes of 18/12, 22/16, and 26/20 °C and atmospheric CO2 concentrations of 350, 675 and 1000 μL L−1 were studied in controlled environment chambers. Plant responses were determined at 20, 40, 67 and 115 (late senescence to maturity) days after planting. Plant height and number of branches increased slightly with CO2 enrichment and more significantly with increasing temperature. Root to shoot ratio remained unchanged at different CO2 concentrations but decreased as temperature increased. Leaf weight ratio and specific leaf weight decreased with increasing temperature. Low temperature reduced dry weight of all plant parts, but the reduction was ameliorated by increasing atmospheric CO2 concentration. The results show that increasing the atmospheric CO2 level causes soybean to grow more vigorously at low temperatures. Although controlled environment experiments have their drawbacks in regard to natural field conditions, the present data indicate that soybean will have enhanced growth even at moderately cool temperatures in the future global CO2 concentrations.Key words: Soybean growth, low temperature, CO2 × temperature interaction, environmental control

A linear quadratic model based on multistage uncertain random systems

2019 ◽  
Vol 47 ◽  
pp. 37-43
Author(s):  
Xin Chen ◽  
Yuanguo Zhu ◽  
Bo Li ◽  
Hongyan Yan
Keyword(s):  
Random Systems ◽  
Quadratic Model ◽  
Linear Quadratic ◽  
Model Based ◽  
Linear Quadratic Model

Response of Sonia roses to continuous daytime CO2 supplementation under controlled environment conditions

1988 ◽  
Vol 39 (5) ◽  
pp. 863 ◽  
Author(s):  
M Zeroni ◽  
J Gale
Keyword(s):  
Leaf Area ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Controlled Environment ◽  
Flower Bud ◽  
Flower Yield ◽  
Co2 Concentrations ◽  
Water Vapour Diffusion ◽  
Flower Quality

Rose plants (Rosa hybrida cv. Sonia, Syn. Sweet Promise) were placed in growth chambers under conditions resembling winter in a controlled environment greenhouse in the desert: mild temperatures, high incident photosynthetic photon flux density (PPFD), high air humidity and 10.5 h daylenght. Concentrations of CO2 in the air were maintained throughout the day at 320, 600 or 1200 8l l-1 with approximately 350 8l l-1 at night. Plant growth (length, fresh and gry weight), development (breaks, blindness), flower yield and flower quality (flower bud diameter, fresh weight and cane length) indices were monitored throughout three consecutive flowering cycles. CO2 supplementation caused an increase in leaf resistance to water vapour diffusion, accompanied by a reduction in the rate of transpiration per unit leaf area, Total leaf area increased at higher CO2 concentrations. Water use per plant did not change. Plant water potentials increased with rising CO2 concentrations. Growth, development, flower yield and flower quality were greatly enahnced in the CO2-enriched atmosphere. The response of growth and development to CO2 supplementation tended to decrease slightly with time when calculated per branch, but increased when calculated per plant. Flower yield and qualtiy did not change with time. The highest CO2 treatment resulted in a sustained, approximately 50% increase in yield, and doubling of the above quality indices throughout the three growth cycles.

Modelling the solar, geomagnetic and periodic variations of the ionosphere over Ethiopia

2020 ◽  
Vol 10 (1) ◽  
pp. 28-39
Author(s):  
T. Gogie
Keyword(s):  
Linear Model ◽  
Satellite Communication ◽  
Linear Time ◽  
Quadratic Model ◽  
Bahir Dar ◽  
Model Based ◽  
Time Series Modelling ◽  
Short Period ◽  
Period Variations ◽  
Periodic Components

A careful and continuous ionospheric modelling can significantly influence the performance of activities such as Positioning, Navigation and Timing services related with the Global Navigation Satellite System applications as well as the Earth Observations System, satellite communication and Space weather forecasting applications. In this paper, the linear time-series modelling that consists of the solar, geomagnetic and periodic components has been carried out on the daily ionospheric vTEC at two different Ethiopian GPS locations, at Arbaminch, ARMI (geographic 6.06ºN, 37.56ºE) and Bahir Dar, BDMT (geographic 11.60ºN, 37.38ºE), for the year 2012, 2014 and 2016 in the 24th solar cycle. The variations of vTEC due to the solar activities, geomagnetic activities and periodic oscillations have been explicitly investigated. The results confirmed that the correlation coefficient of the linear model based estimated vTEC and the observed GPS-vTEC is around 80% in the year 2014. Besides, solar activity is identified as the key component for the 27 days period variations of vTEC whereas geomagnetic activity is identified as the key component that influences the short-period variations of the daily average vTEC. In addition to the correlation analysis, the accuracy of the model has been assessed by comparing the International Reference Ionosphere (IRI 2016) model based vTEC and GPS-vTEC measurements as well as with the quadratic model based vTEC. Consequently, the linear model formulated with the solar, geomagnetic and periodic components significantly captured the variations (78-80%) of the observed vTEC compared with both the IRI 2016 and the quadratic models during the years 2012, 2014 and 2016. The comparison of the observed and predicted vTEC variations has also been examined using the continuous wavelet transform. The decomposed waves from the wavelet analysis have revealed that the predicted and observed vTEC have had simultaneous periods of variations specifically with the period of 27 days whereas the IRI 2016 could capture the short-period variations of vTEC. Moreover, the analysis from the transformed data in the year 2014 over both Arbaminch and Bahir Dar has indicated that the linear model based vTEC and the observed GPS-vTEC have had common pattern of variations with the period of 27 days that had lasted for 150 days (from day of the year 100 to 250).

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