Optimal control of environmental conditions affecting lettuce plant growth in a controlled environment with artificial lighting: A review

2020 ◽  
Vol 130 ◽  
pp. 75-89
Author(s):  
Hesham A. Ahmed ◽  
Tong Yu-Xin ◽  
Yang Qi-Chang
Keyword(s):  
Optimal Control ◽  
Plant Growth ◽  
Environmental Conditions ◽  
Controlled Environment ◽  
Lettuce Plant ◽  
Artificial Lighting

scholarly journals (295) Measuring and Reporting Growing Conditions in Controlled Environments

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1009B-1009
Author(s):  
Marc W. van Iersel
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Working Group ◽  
International Committee ◽  
Controlled Environment ◽  
The North ◽  
Controlled Environments ◽  
Air Speed ◽  
Growing Conditions ◽  
Replication Of Experiments

Do you accurately measure and report the growing conditions of your controlled environment experiments? Conditions in controlled environment plant growth rooms and chambers should be reported in detail. This is important to allow replication of experiments on plants, to compare results among facilities, and to avoid artefacts due to uncontrolled variables. The International Committee for Controlled Environment Guidelines, with representatives from the U.K. Controlled Environment Users' Group, the North American Committee on Controlled Environment Technology and Use (NCR-101), and Australasian Controlled Environment Working Group (ACEWG), has developed guidlines to report environmental conditions in controlled environment experiments. These guidelines include measurements of light, temperature, humidity, CO2, air speed, and fertility. A brochure with these guidelines and a sample paragraph on how to include this information in a manuscript will be available.

scholarly journals Physiology of Methylotrophs Living in the Phyllosphere

2021 ◽  
Vol 9 (4) ◽  
pp. 809
Author(s):  
Hiroya Yurimoto ◽  
Kosuke Shiraishi ◽  
Yasuyoshi Sakai
Keyword(s):  
Plant Growth ◽  
Crop Yield ◽  
Environmental Conditions ◽  
Sole Source ◽  
Current Understanding ◽  
Methylotrophic Bacteria ◽  
Cellular Mechanisms ◽  
Diurnal Cycles ◽  
Promote Plant Growth ◽  
Increase Crop Yield

Methanol is abundant in the phyllosphere, the surface of the above-ground parts of plants, and its concentration oscillates diurnally. The phyllosphere is one of the major habitats for a group of microorganisms, the so-called methylotrophs, that utilize one-carbon (C1) compounds, such as methanol and methane, as their sole source of carbon and energy. Among phyllospheric microorganisms, methanol-utilizing methylotrophic bacteria, known as pink-pigmented facultative methylotrophs (PPFMs), are the dominant colonizers of the phyllosphere, and some of them have recently been shown to have the ability to promote plant growth and increase crop yield. In addition to PPFMs, methanol-utilizing yeasts can proliferate and survive in the phyllosphere by using unique molecular and cellular mechanisms to adapt to the stressful phyllosphere environment. This review describes our current understanding of the physiology of methylotrophic bacteria and yeasts living in the phyllosphere where they are exposed to diurnal cycles of environmental conditions.

Numerical Simulation of the “Floating Spiral” Pipeline Installation Procedure: Second Stage, Spiral Transportation, Behavior Under Waves

2008 ◽  
Author(s):  
Bruno Martins Jacovazzo ◽  
Fabri´cio Nogueira Correˆa ◽  
Carl Horst Albrecht ◽  
Breno Pinheiro Jacob ◽  
Fernando Gomes da Silva Torres ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Optimal Control ◽  
Environmental Conditions ◽  
Companion Paper ◽  
Time Constraints ◽  
Second Stage ◽  
Parametric Studies ◽  
Large Length ◽  
Transportation Behavior ◽  
Flat Spiral

The Floating Spiral pipeline installation method consists basically in winding the pipeline into a huge floating spiral, and towing this assembly to the installation site, where the spiral is then unwound and lowered to the seabed. In this method the pipeline is fabricated onshore, as the spiral is created, under well controlled conditions and relatively relaxed time constraints. Therefore the welds can be better inspected, which allows for optimal control of quality in pipeline manufacturing. The first stage of the installation process by this method consists in setting the pipeline afloat and winding it elastically to form a large flat spiral. This stage is studied in a companion paper [1], to be also presented at IPC2008. The second stage consists in towing the floating spiral pipeline employing standard tugboats before laying it at the installation site. The objective of this work is, therefore, to present results of parametric studies for a large length pipeline at this second stage of the Floating Spiral method. The focus now is in the pipeline behavior under wave environmental conditions during transportation. Several numerical simulations are performed and the results are discussed and compared.

scholarly journals Abiotic Stresses Shift Belowground Populus-Associated Bacteria Toward a Core Stress Microbiome

mSystems ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Collin M. Timm ◽  
Kelsey R. Carter ◽  
Alyssa A. Carrell ◽  
Se-Ran Jun ◽  
Sara S. Jawdy ◽  
...  
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Bacterial Communities ◽  
Abiotic Stresses ◽  
Growth Conditions ◽  
Plant Host ◽  
Associated Bacteria ◽  
Poplar Trees

The identification of a common “stress microbiome” indicates tightly controlled relationships between the plant host and bacterial associates and a conserved structure in bacterial communities associated with poplar trees under different growth conditions. The ability of the microbiome to buffer the plant from extreme environmental conditions coupled with the conserved stress microbiome observed in this study suggests an opportunity for future efforts aimed at predictably modulating the microbiome to optimize plant growth.

scholarly journals Strip-till technology - a method for uniformity in the emergence and plant growth of winter rapeseed (Brassica napus L.) in different environmental conditions of Northern Poland

2018 ◽  
pp. 194-199 ◽  
Author(s):  
Iwona Jaskulska ◽  
Lech Gałęzewski ◽  
Mariusz Piekarczyk ◽  
Dariusz Jaskulski
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Block Design ◽  
Thermal Conditions ◽  
Weather Conditions ◽  
Field Trials ◽  
Initial Growth ◽  
Brassica Napus L ◽  
Initial Development ◽  
Winter Rapeseed

The emergence of plants is especially important for the winter crops that are grown in the challenging environmental conditions of many countries in Central and Eastern Europe. The emergence and initial growth of winter rapeseed were compared in field trials in a randomized block design with three replicates for plants sown in conventional tillage systems (CT) and strip-till (ST), which had different weather conditions and on soil with a non-uniform texture over a period of two years. Sowing in the CT was carried out using Horsch Pronto 4DC (Germany) at a row distance of 0.29 m. The ST operations were performed using a Pro-Til 4T drill manufactured by Mzuri Limited (Great Britain) - row spacing of 0.36 m. In favourable rainfall and thermal conditions, the density of winter rapeseed plants two weeks after sowing was found to be higher if it was sown after the CT than in the ST system. In the year that had a serious shortage of rainfall during the sowing period, a considerably higher density of plants was achieved using the ST system. The uniformity of plant growth using the ST technology in soil with a varied texture, especially in a year with an unfavourable distribution of rainfall, was proven by less variability in the number of leaves in the rosette, in the dry mass of the leaf rosette and in the root neck thickness of the winter rapeseed than in the CT system. The ST system can create good conditions for the initial development and preparation of rapeseed plants for wintering.

Biofertilizers-Mediated Sustainable Plant Growth and Production Under Adverse Environmental Conditions

2021 ◽  
pp. 437-457
Author(s):  
Swetika Porwal ◽  
Akhilesh Kumar Singh ◽  
Ashok Kumar Yadav ◽  
Sudhir Kumar ◽  
Paras Porwal
Keyword(s):  
Plant Growth ◽  
Environmental Conditions ◽  
Adverse Environmental Conditions

Thioproline Protection of Crops Against Herbicide Toxicity

1988 ◽  
Vol 2 (1) ◽  
pp. 72-76 ◽  
Author(s):  
James L. Hilton ◽  
Parthasarathy Pillai
Keyword(s):  
Zea Mays ◽  
Carboxylic Acid ◽  
Plant Growth ◽  
Sorghum Bicolor ◽  
Controlled Environment ◽  
Seedling Roots ◽  
Thiol Content ◽  
Herbicide Toxicity

Thioproline (L-thiazolidine-4-carboxylic acid) partially protects sorghum [Sorghum bicolor(L.) Moench. ‘DK 42Y’] seedlings against the herbicides tridiphane [2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane] and alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] in controlled environment chambers. Thioproline alone inhibits plant growth at concentrations above 10−5M. Its phytotoxicity is intermediate between the two herbicide antidotes OTC (L-2-oxothiazolidine-4-carboxylic acid) and flurazole [phenylmethyl 2-chloro-4-(trifluoromethyl)-5-thiazolecarboxylate]. The two thiazolidine antidotes increased thiol content of excised corn (Zea maysL. ‘DK T 1100’) seedling roots whereas thiol content was decreased by the two herbicides. While thioproline or OTC partially offset tridiphane-induced decreases in thiol content, none of the antidotes effectively circumvented the reduced thiol content resulting from alachlor treatment.

An optimal control methodology for plant growth—Case study of a water supply problem of sunflower

2012 ◽  
Vol 82 (5) ◽  
pp. 909-923 ◽  
Author(s):  
Lin Wu ◽  
François-Xavier Le Dimet ◽  
Philippe de Reffye ◽  
Bao-Gang Hu ◽  
Paul-Henry Cournède ◽  
...  
Keyword(s):  
Optimal Control ◽  
Plant Growth ◽  
Water Supply ◽  
Supply Problem ◽  
Control Methodology

scholarly journals Development of MILIONCAST, an Improved Model for Predicting Downy Mildew Sporulation on Onions

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 695-702 ◽  
Author(s):  
Tijs Gilles ◽  
Kath Phelps ◽  
John P. Clarkson ◽  
Roy Kennedy
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Temporal Pattern ◽  
Random Model ◽  
Controlled Environment ◽  
High Humidity ◽  
Potted Plants ◽  
Effects Of Temperature ◽  
Improved Model ◽  
Accuracy Of Prediction

The effects of temperature and relative humidity on Peronospora destructor sporulation on onion (Allium cepa) leaves were studied under controlled environmental conditions. Sporangia were produced most rapidly at 8 to 12°C after 5 h of high humidity during dark periods. The greatest number of sporangia was produced at 100% relative humidity (RH), and sporulation decreased to almost nil when humidity decreased to 93% RH. A model, named MILIONCAST (an acronym for MILdew on onION foreCAST), was developed based on the data from these controlled environment studies to predict the rate of sporulation in relation to temperature and relative humidity. The accuracy of prediction of sporulation was evaluated by comparing predictions with observations of sporulation on infected plants in pots outdoors. The accuracy of MILIONCAST was compared with the accuracy of existing models based on DOWNCAST. MILIONCAST gave more correct predictions of sporulation than the DOWNCAST models and a random model. All models based on DOWNCAST were more accurate than the random model when compared on the basis of all predictions (including positive and negative predictions), but they gave fewer correct predictions of sporulation than the random model. De Visser's DOWNCAST and ONIMIL improved their accuracy of prediction of sporulation events when the threshold humidity for sporulation was reduced to 92% RH. The temporal pattern of predicted sporulation by MILIONCAST generally corresponded well to the pattern of sporulation observed on the outdoor potted plants at Wellesbourne, UK.

Expression and relationships of resistance to white rust (Albugo candida) at cotyledonary, seedling, and flowering stages in Brassica juncea germplasm from Australia, China, and India

2007 ◽  
Vol 58 (3) ◽  
pp. 259 ◽  
Author(s):  
C. X. Li ◽  
K. Sivasithamparam ◽  
G. Walton ◽  
P. Salisbury ◽  
W. Burton ◽  
...  
Keyword(s):  
Plant Growth ◽  
Brassica Juncea ◽  
Environmental Conditions ◽  
Host Resistance ◽  
Growth Stages ◽  
Sources Of Resistance ◽  
Albugo Candida ◽  
White Rust ◽  
China And India ◽  
Canola Quality

White rust (Albugo candida) is a highly destructive disease of oilseed Brassicas such as Brassica juncea and B. rapa. Most commercial B. juncea or B. rapa varieties are highly susceptible and yield losses from combined infection of leaves and inflorescences can be up to 20% or 60% in Australia and India, respectively. In Australia, canola-quality B. juncea has been developed to extend oilseed Brassica production into lower rainfall areas, with the first commercial B. juncea canola-quality variety planned for release in 2006. It is essential to identify useful sources of host resistance in B. juncea as breeding and/or selection of material for resistance is the most cost-effective method of delivering control for farmers. Three experiments were undertaken under controlled-environmental conditions to identify the best methods of characterising host resistance and to identify sources of resistance in B. juncea germplasm from Australia, China, and India. Forty-four B. juncea genotypes, viz. 22 from India, 12 from Australia, and 10 from China, were tested. Four Chinese genotypes (CBJ-001, CBJ-002, CBJ-003, CBJ-004) and one Australian genotype (JR049) consistently showed high resistance to A. candida across the different plant growth stages against a pathotype prevailing in Australia. Similarly, the most susceptible genotypes (viz. Indian genotypes RH781, RL1359, RH819) were extremely susceptible irrespective of the plant growth stage. Overall, although disease severity on cotyledons and leaves at the different growth stages was significantly and positively correlated, there was, however, no significant correlation between the number of stagheads and any of the other disease parameters measured. Our study demonstrates that controlled-environmental conditions are suitable for rapid identification of resistant genotypes and that genotypes with high levels of resistance can be reliably identified at the cotyledonary, seedling, or flowering stages.

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