The Influence of Hardening and Waterlogging on the Frost Resistance of Subalpine Eucalypts.

1987 ◽  
Vol 35 (1) ◽  
pp. 91 ◽  
Author(s):  
NJ Davidson ◽  
JB Reid
Keyword(s):  
Significant Role ◽  
Frost Resistance ◽  
Significant Interaction ◽  
Growing Season ◽  
Reciprocal Transplant ◽  
Frost Hardening ◽  
Interspecific Differences ◽  
Ecological Importance ◽  
Field Transplant ◽  
Slight Damage

Marked interspecific differences in frost resistance were shown to exist between eucalypt seedlings grown in reciprocal field transplant trials conducted at a frost hollow on Snug Plains, south-eastern Tasmania. Populations of the six eucalypt species tested naturally inhabited the margins and base of this frost hollow. A growing season frost of - 5.5°C caused substantial damage to E. delegatensis, E. pulchella, E. urnigera, E. johnstonii and E. coccifera but only slight damage to E. gunnii. A winter frost of - 10.5°C caused markedly less damage than the growing season frost, suggesting that appreciable hardening occurs in winter and that growing season frosts may play a significant role in determining the distribution of subalpine eucalypts. E. pulchella appeared more resistant to growing season frosts than E. delegatensis while the reverse occurred in all but one of the experimental gardens during winter frosts. The reasons for this reversal and its significance are discussed. Frost chamber experiments confirmed the major differences between species in frost resistance and the importance of hardening. The reciprocal transplant trials suggested that seedlings from subgenus Symphyomyrtus were more frost resistant than those from subgenus Monocalyptus in sites prone to waterlogging. This was sup- ported by frost chamber trials in which a significant interaction between frost resistance and waterlog- ging was demonstrated. Species from subgenus Monocalyptus showed a reduced ability to harden under waterlogged conditions compared with species from subgenus Symphyomyrtus. This interaction may be of ecological importance since species from subgenus Monocalyptus do not occur in cold, waterlogged sites at Snug Plains. The present and previous experiments suggest that the distribution of subalpine eucalypts is dependent upon the interaction of a range of factors including the severity of winter frosts, resistance to growing season frosts, the suitability of the site for frost hardening and the degree of waterlogging.

scholarly journals The effects of short-term light exposure on subjective affect and comfort are dependent on the lighting time of day

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lijun Chen ◽  
Fang-Fang Yan ◽  
Shuhan Fan ◽  
Yifan Wu ◽  
Jia Yang ◽  
...  
Keyword(s):  
Significant Role ◽  
Negative Correlation ◽  
Significant Interaction ◽  
Daily Life ◽  
Light Exposure ◽  
Time Of Day ◽  
Color Temperature ◽  
Subjective Feeling ◽  
Short Term ◽  
Illuminance Level

AbstractLight, one of the key environmental components for both life and work, played significant role in subjective feelings (e.g. affect and comfort), but the exact effects and mechanisms were still to be determined. The present study screened thirty healthy adults (13 females, 22.45 ± 3.26 years) and examined subjective affect and comfort under short-term white lights with different combination of correlated color temperature (CCT) and illuminance at different times of day (e.g. morning, afternoon, and evening). Our results showed a significant interaction between illuminance level and time-of-day on subjective comfort. Participants felt more comfortable under 50 lx and 100 lx instead of 500 lx in the evening, and more comfortable under 500 lx in the morning and afternoon. In addition, a positive correlation between illuminance and comfort in the morning and a negative correlation between them in the evening were found. No significant effect of CCT on any subjective feeling was revealed. Our results necessitate the consideration of time-of-day in understanding lighting effects and application of healthy lighting in daily life.

scholarly journals Use of the delayed luminescence test for evaluation of changes in frost-resistance of winter wheat

2013 ◽  
Vol 38 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Aleksander Brzóstowicz ◽  
Zdzisław Prokowski ◽  
Antoni Murkowski ◽  
Edward Grabikowski
Keyword(s):  
Winter Wheat ◽  
Frost Resistance ◽  
Winter Season ◽  
Wheat Cultivars ◽  
Delayed Luminescence ◽  
Luminescence Method ◽  
Frost Hardening ◽  
Conductometric Method ◽  
Winter Wheat Cultivars ◽  
Autumn And Winter

The influence of frost hardening conditions on the frost-resistance of three winter wheat cultivars ('Mironowska 808', 'Grana' and 'Maris Huntsman') was studied. Frost resistance was measured periodically during the autumn and winter season by the delayed luminescence method. Parallelly an electrical conductivity test was performed for comparison. It was found that the temperature which delayed luminescence reaches its maximum (t<sub>N</sub>) correlates with (t<sub>50</sub>) obtained by the conductometric method. The differences in response of particular cultivars to frost and hardening conditions are described.

EFFECT OF DROUGHT ON FROST RESISTANCE AND FATTY ACID CONTENT OF YOUNG WINTER WHEAT PLANTS

1979 ◽  
Vol 59 (3) ◽  
pp. 639-643 ◽  
Author(s):  
C. WILLEMOT ◽  
L. PELLETIER
Keyword(s):  
Drought Stress ◽  
Winter Wheat ◽  
Frost Resistance ◽  
Fatty Acid Content ◽  
Triticum Aestivum L ◽  
Temperature Treatment ◽  
Frost Hardening ◽  
Low Temperature Treatment ◽  
Degree Of Unsaturation ◽  
Water Holding

Low soil moisture, both prior to and during freezing, increased frost resistance of 12-day-old winter wheat (Triticum aestivum L.) plants. While frost resistance increased, percentage of linolenic acid decreased in drought-stressed plants (10% of soil water-holding capacity) as compared with controls (40%). This occurred whether drought stress was applied before freezing at 1 °C or at 20 °C. A degree of frost hardening can be achieved in winter wheat by drought stress without low temperature treatment, and without an increase in degree of unsaturation of fatty acids.

Time-of-day Dependent Light Effects on Subjective Affect and Comfort

2020 ◽  
Author(s):  
Lijun Chen ◽  
Fangfang Yan ◽  
Shuhan Fan ◽  
Yifan Wu ◽  
Jia Yang ◽  
...  
Keyword(s):  
Significant Role ◽  
Negative Correlation ◽  
Significant Interaction ◽  
Daily Life ◽  
Time Of Day ◽  
Color Temperature ◽  
Subjective Feeling ◽  
Short Term ◽  
Illuminance Level ◽  
Light Effects

Abstract Light, one of the key environmental components for both life and work, played significant role in subjective feelings (e.g. affect and comfort), but the exact effects and mechanisms were still to be determined. The present study screened thirty healthy adults (13 females, 22.45 ± 3.26 years) and examined subjective affect and comfort under short-term white lights with different combination of correlated color temperature (CCT) and illuminance at different times of day (e.g. morning, afternoon, and evening). Our results showed a significant interaction between illuminance level and time-of-day on subjective comfort. Participants felt more comfortable under 50 lx and 100 lx instead of 500 lx in the evening, and more comfortable under 500 lx in the morning and afternoon. In addition, a positive correlation between illuminance and comfort in the morning and a negative correlation between them in the evening were found. No significant effect of CCT on any subjective feeling was revealed. Our results necessitate the consideration of time-of-day in understanding lighting effects and application of healthy lighting in daily life.

scholarly journals Silicate and phosphate combinations for marandu palisadegrass growing on an oxisol

2007 ◽  
Vol 64 (3) ◽  
pp. 275-281 ◽  
Author(s):  
Suzana Pereira de Melo ◽  
Francisco Antonio Monteiro ◽  
Daniel Manfredini
Keyword(s):  
Leaf Area ◽  
Mass Production ◽  
Significant Interaction ◽  
Growing Season ◽  
Dry Mass ◽  
Phosphorus Availability ◽  
Available Phosphorus ◽  
Brachiaria Brizantha ◽  
Total Leaf Area ◽  
Low Concentrations

One of the greatest problems for pasture establishment and maintenance are the extremely low concentrations of available phosphorus in soils. The objective of this study was to evaluate the influences on productive and physiologic attributes during Marandu palisadegrass (Brachiaria brizantha) establishment, following changes in phosphorus availability in the soil through the applications of phosphate and silicate. To achieve this, a fractionated factorial 5² design was used, with 13 combinations for silicon and phosphorus, respectively, in mg dm-3: 150 and 10; 150 and 170; 150 and 330; 225 and 90; 225 and 250; 300 and 10; 300 and 170; 300 and 330; 375 and 90; 375 and 250; 450 and 10; 450 and 170 and 450 and 330, distributed according to randomized blocks, with four replications. The experiment was carried out in a greenhouse using samples of a Typic Haplustox (760 g kg-1 sand, 40 g kg-1 silt and 200 g kg-1 clay). Wollastonite was used as the source of silicate and the sources of phosphorus were Ca(H2PO4)2, KH2PO4 and NaH2PO4. Marandu palisadegrass was grown during the summer and two harvests were made during the growing season. Significant interaction between phosphorus and silicate rates was found for the number of tillers and expanded green leaves, total leaf area, dry mass production of leaf laminae and culms with sheaths, and dry mass production of plant tops. Maximum responses of the analyzed variables were reached in the combination of the intermediate rates of phosphorus (170 and 250 mg dm-3) with high rates of silicon (375 and 450 mg dm-3).

INFLUENCE DE LA LUMIERE ET DE LA TEMPERATURE SUR LA TENEUR EN ACIDE LINOLENIQUE ET LA RESISTANCE AU GEL DU BLE D’HIVER

1980 ◽  
Vol 60 (2) ◽  
pp. 349-355 ◽  
Author(s):  
C. WILLEMOT ◽  
L. PELLETIER
Keyword(s):  
Low Temperature ◽  
Winter Wheat ◽  
Linolenic Acid ◽  
Mode Of Action ◽  
Frost Resistance ◽  
Frost Hardiness ◽  
Frost Hardening ◽  
Long Time

The correlation between accumulation of linolenic acid in the crowns and roots of winter wheat and its frost hardening at low temperature is indirect. It results from their common requirement for light and low temperature. Light mainly produces energy and carbon reserves. The partial hardening obtained in darkness could be eliminated by preetiolation. The high levels of linolenic acid and frost resistance reached after hardening were maintained for a long time in darkness. The levels of linolenic acid and frost hardiness decreased faster at low temperature in hardened plants after treatment with BASF 13-338, a substituted pyridazinone, than in plants deprived of light. The mode of action of BASF 13-338 is apparently not limited to the inhibition of photosynthesis.

Sign in / Sign up

Export Citation Format

Share Document