Photoperiod and night frost influence the frost hardiness of Chamaecyparisnootkatensis clones

1993 ◽  
Vol 23 (7) ◽  
pp. 1408-1414 ◽  
Author(s):  
B.J. Hawkins
Keyword(s):  
Electrolyte Leakage ◽  
Frost Hardiness ◽  
Relative Influence ◽  
Controlled Environment ◽  
Rooted Cuttings ◽  
Subzero Temperatures ◽  
Controlled Environments

Frost hardiness in yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach) was studied over the winter to determine the relative influence of photoperiod and subzero temperatures on the hardening and dehardening processes. Stecklings (rooted cuttings) of five clones from each of three provenances were grown outdoors and in two controlled-environment chambers at 10:5 °C day:night temperatures and 12- or 6-h photoperiods. Half of the plants in each photoperiod treatment were subject to a 4-h night frost, three times per week from December through to March. Frost hardiness was assessed at intervals using the freeze-induced electrolyte leakage method. Variability in frost hardiness was greater among clones within provenances than among provenances. Significant differences in hardiness among clones existed throughout the experiment; however, the ranking of clones by hardiness was not consistent. Stecklings in the 6-h photoperiod were consistently more hardy than their counterparts subjected to 12-h photoperiods. Stecklings placed outdoors had equivalent hardiness to those in the 6-h photoperiod until the advent of natural frosts in January. At this time, the outdoor trees were the most hardy. Night frost also significantly increased frost hardiness in stecklings in controlled environments. Stecklings in all treatments began to deharden between January and March. The outdoor plants dehardened most rapidly. Stecklings in the controlled environments dehardened slowly until the night-frost treatment ended, whereupon previously frozen plants dehardened more rapidly than their unfrozen counterparts.

Photoperiod influences dehardening of Chamaecyparisnootkatensis seedlings

1993 ◽  
Vol 23 (11) ◽  
pp. 2452-2454 ◽  
Author(s):  
B.J. Hawkins ◽  
S.E. McDonald
Keyword(s):  
Significant Influence ◽  
Electrolyte Leakage ◽  
Frost Hardiness ◽  
Controlled Environment

In early January, seedlings of yellow cypress (Chamaecyparisnootkatensis (D. Don) Spach) were placed in controlled-environment chambers under constant, increasing, and decreasing photoperiods. Seedlings from all treatments were assessed for frost hardiness at 2-week intervals using the freeze-induced electrolyte leakage method. Seedlings subject to increasing day lengths began to deharden immediately and at a greater rate than seedlings under a constant photoperiod. Seedlings in the decreasing photoperiod treatment maintained maximum hardiness for 42 days and then began to deharden spontaneously, although photoperiod continued to decrease. Once dehardening began in this treatment, it proceeded at the fastest rate of all treatments. These results indicate that photoperiod has a significant influence on the initiation and rate of dehardening in yellow cypress, and maximum hardiness cannot be maintained indefinitely.

Effect of population, environment, and maturation on the frost hardiness of yellow-cedar (Chamaecyparisnootkatensis)

1994 ◽  
Vol 24 (5) ◽  
pp. 945-953 ◽  
Author(s):  
B.J. Hawkins ◽  
J. Russell ◽  
R. Shortt
Keyword(s):  
Air Temperature ◽  
Electrolyte Leakage ◽  
High Elevation ◽  
Genetic Component ◽  
Frost Hardiness ◽  
Diverse Populations ◽  
Rooted Cuttings ◽  
Stock Types

Three 2-year-old experimental plantations of yellow-cedar (Chamaecyparisnootkatensis (D. Don) Spach.) seedlings and stecklings (rooted cuttings) from 4- and 12-year-old hedges were analyzed periodically for frost hardiness between September 1991 and May 1992. The plantations were at different elevations and latitudes, and seedlings and stecklings of three geographically diverse populations were represented. Frost hardiness was assessed using the freeze-induced electrolyte leakage method on upper, primary branches. Air temperature at the low elevation sites was monitored. Frost hardiness of all plants increased from September to the end of January, and then decreased. Plants grown at high elevation were consistently more hardy than those grown at low elevation; however, no obvious differences in hardiness between the two latitudes were evident. Seedlings and stecklings of parents from certain families and populations developed greater hardiness than stock of parents from other areas, showing that frost hardiness of yellow-cedar plants has a genetic component. The three stock types did not show any consistent, significant differences in hardiness; however, stecklings from 12- and 4-year-old hedges were, on average, slightly more hardy than seedlings.

scholarly journals Opportunities and limits of controlled-environment plant phenotyping for climate response traits

2021 ◽  
Author(s):  
Anna Langstroff ◽  
Marc C. Heuermann ◽  
Andreas Stahl ◽  
Astrid Junker
Keyword(s):  
Crop Production ◽  
Field Trials ◽  
Plant Phenotyping ◽  
Controlled Environment ◽  
Climate Response ◽  
Negative Effects ◽  
Phenotypic Data ◽  
Non Invasive ◽  
Controlled Environments ◽  
Response Traits

AbstractRising temperatures and changing precipitation patterns will affect agricultural production substantially, exposing crops to extended and more intense periods of stress. Therefore, breeding of varieties adapted to the constantly changing conditions is pivotal to enable a quantitatively and qualitatively adequate crop production despite the negative effects of climate change. As it is not yet possible to select for adaptation to future climate scenarios in the field, simulations of future conditions in controlled-environment (CE) phenotyping facilities contribute to the understanding of the plant response to special stress conditions and help breeders to select ideal genotypes which cope with future conditions. CE phenotyping facilities enable the collection of traits that are not easy to measure under field conditions and the assessment of a plant‘s phenotype under repeatable, clearly defined environmental conditions using automated, non-invasive, high-throughput methods. However, extrapolation and translation of results obtained under controlled environments to field environments is ambiguous. This review outlines the opportunities and challenges of phenotyping approaches under controlled environments complementary to conventional field trials. It gives an overview on general principles and introduces existing phenotyping facilities that take up the challenge of obtaining reliable and robust phenotypic data on climate response traits to support breeding of climate-adapted crops.

Effects of photoperiod and temperature on flowering of twelve Stylosanthes species

1977 ◽  
Vol 17 (86) ◽  
pp. 417 ◽  
Author(s):  
DF Cameron ◽  
L't Mannetje ◽  
Mannetje L 't
Keyword(s):  
High Temperatures ◽  
Reproductive Strategies ◽  
Photoperiod Response ◽  
Controlled Environment ◽  
Climatic Adaptation ◽  
Short Day ◽  
Long Day ◽  
Controlled Environments ◽  
Delayed Flowering ◽  
Strong Control

The flowering of accessions from 12 Stylosanthes species was studied in two controlled environment experiments and a glasshouse experiment. In controlled environments photoperiod exerted a strong control over flowering with short day, day neutral and long day responses being recognized. High temperatures generally delayed flowering, increased the node of first flower and reduced the number of inflorescences, but acted as a modifier only of the basic control exerted by photoperiod. With natural photoperiods in the glasshouse, flowering responses were generally consistent with the photoperiod responses observed in controlled environments. The climatic adaptation of Stylosanthes species is discussed in relation to the alternative reproductive strategies of the photoperiod response types.

Consistency as the True Measure of Cleanroom Wiper Quality

2011 ◽  
Vol 54 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Sandeep Kalelkar ◽  
Jay Postlewaite
Keyword(s):  
Structural Design ◽  
Test Methods ◽  
Controlled Environment ◽  
Test Results ◽  
Data Points ◽  
Controlled Environments ◽  
Single Data ◽  
True Measure ◽  
Test Result ◽  
Selection Of

Cleanroom wipers have long played an indispensable role in managing contamination in controlled environments. From wiping residues on hard surfaces to applying cleaning solutions, wipers perform a variety of tasks that help maintain the cleanliness levels desired in a given cleanroom environment. This makes the selection of cleanroom wipers a critical decision in any controlled environment. One common way to distinguish between cleanroom wipers of similar structural design is to compare test results across a variety of criteria, according to recommended practices by organizations such as the IEST. However, these results are typically listed as single data points for a given test and are meant to indicate either "typical values," or even target specifications, in some instances. This approach is inherently limited and ineffective in assessing the true levels of cleanliness of a given wiper product. In this study, we review the test methods that are used to evaluate cleanroom wipers and present a new and improved approach by which users can evaluate their cleanliness. We provide a framework by which the consistency of the cleanliness of cleanroom wipers can be assessed in a statistically relevant manner. Finally, we demonstrate the value of using consistency of test results rather than a singular test result as the true measure of wiper quality.

Interactions between field populations of the potato cyst nematode Globodera pallida and Rhizoctonia solani diseases of potatoes under controlled environment and glasshouse conditions

Nematology ◽  
2010 ◽  
Vol 12 (5) ◽  
pp. 783-790 ◽  
Author(s):  
Shuvash Bhattarai ◽  
Patrick P.J. Haydock ◽  
Matthew A. Back ◽  
Martin C. Hare ◽  
William T. Lankford
Keyword(s):  
Rhizoctonia Solani ◽  
Early Stage ◽  
Disease Incidence ◽  
Globodera Pallida ◽  
Controlled Environment ◽  
Second Stage ◽  
Potato Plants ◽  
Juvenile Population ◽  
Controlled Environments ◽  
Two Populations

Abstract This research elucidates interactions between Globodera pallida and Rhizoctonia solani (AG3) by comparing disease development in potato plants inoculated with G. pallida and R. solani. The effects of juvenile population density and time of infestation on R. solani disease were investigated in controlled environments. Plants were inoculated with a range of densities of second-stage juveniles (J2) of G. pallida (800, 4000, 10 000, 20 000 and 40 000 J2/plant) and R. solani at 2, 4 and 6 weeks after planting and a single treatment of G. pallida density and R. solani alone. The experiment demonstrated that greatest disease incidence and severity occurred when high population densities of G. pallida were applied at an early stage of plant development. To determine if this effect could explain differences in R. solani disease incidence and severity following interactions with individual field populations of G. pallida, a glasshouse experiment was conducted using two populations of G. pallida with known hatching characteristics (fast and slow hatching). The experiment revealed that a combination of a fast-hatching population with R. solani caused significantly more R. solani disease incidence and severity than a population of G. pallida with slower hatching characteristics.

SCREENING FOR SCALD RESISTANCE IN BARLEY GROWN AT HIGH PLANT DENSITY IN CONTROLLED ENVIRONMENTS

1989 ◽  
Vol 69 (1) ◽  
pp. 235-238
Author(s):  
K. W. MAY ◽  
F. R. HARPER
Keyword(s):  
Hordeum Vulgare ◽  
Plant Density ◽  
Rhynchosporium Secalis ◽  
Controlled Environment ◽  
Limited Space ◽  
High Plant Density ◽  
Spray Inoculation ◽  
Controlled Environments

A method of spray inoculation with the scald (Rhynchosporium secalis) incitant was highly reliable in differentiating susceptible and resistant barley plants grown at high plant density in a controlled environment. Segregating populations can be efficiently screened under precise conditions in the limited space available in controlled environment chambers.Key words: Hordeum vulgare, Rhynchosporium secalis, scald, screening, resistance, high plant density

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.

A comparison of analytical approaches for assessing freezing damage in black spruce using electrolyte leakage methods

1996 ◽  
Vol 74 (6) ◽  
pp. 952-958 ◽  
Author(s):  
K. D. Odlum ◽  
T. J. Blake
Keyword(s):  
Critical Temperature ◽  
Electrolyte Leakage ◽  
Black Spruce ◽  
Frost Hardiness ◽  
Initial Increase ◽  
Cool Temperature ◽  
Freezing Damage ◽  
Intact Seedling ◽  
Temperature Hardening ◽  
Analytical Approaches

To compare different methods of quantifying shoot frost damage during controlled plant freezing tests, frost hardening of black spruce (Picea mariana (Mill.) BSP) seedlings exposed to three temperature hardening regimes over 16 weeks was assessed using electrolyte leakage and intact seedling methods. Electrolyte leakage was expressed as index of injury and was quantified either as the temperature needed to induce an index of injury of 5% (DT5) or as the critical temperature (CT), the mildest temperature at which damage was first detected statistically. Damage to intact shoots was expressed as percent shoot browning and was quantified as the temperature at which 50% of needle tissue on the shoots was damaged (sLT50) or as the temperature at which 50% of terminal buds were killed (bLT50). Seedling response to hardening temperature varied, depending on the method used to quantify frost hardiness. When expressed as critical temperature, hardening continued over the 16 weeks at a constant rate with no differences detected between treatments. Intact seedling shoot damage, sLT50 and bLT50, described a hardening process in which there was a large initial increase in hardening in the first 8 weeks, with less hardening occurring during the subsequent 8 weeks. Also, significant temperature effects were detected, with the greatest hardening occurring in a cool temperature (4 °C), the least in a warm temperature (20 °C), and an intermediate amount in a moderate temperature (10 °C). When quantified as DT5, the pattern of hardening was somewhat intermediate to the other two. Methods of determining frost hardiness were highly correlated, with the strongest correlation being between sLT50 and bLT50 (r2 = 0.903). Both electrolyte leakage methods, DT5 and CT, were linearly related to one another (r2 = 0.666) and were more sensitive than the intact seedling methods, since they both detected damage at warmer temperatures. DT5 was better correlated to intact measures of hardiness than was CT. Keywords: black spruce, index of injury, frost hardiness, critical temperature, damaging temperature, LT50.

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