OVER-WINTER STORAGE OF CONIFEROUS SEEDLINGS AS A MEANS OF PREVENTING LATE FROST DAMAGE

In a series of experiments on over-winter storage, seedlings of white spruce and other conifers were placed in normal shipping hales and stored in root cellars without artificial refrigeration. White spruce seedlings were retained in dormant condition for approximately six months without apparent damage to their later performance in plantations. Stored seedlings proved highly resistant to damage from spring frosts and therefore superior to spring-shipped stock from the same nursery beds. Conclusive evidence of the suitability of other conifers for over-winter storage was not obtained. The application of over-winter storage of white spruce seedlings in planting operations in northern Ontario is discussed.

Download Full-text

Inheritance and correlations of frost injury, growth, flowering, and cone characteristics in white spruce, Piceaglauca (Moench) Voss

Canadian Journal of Forest Research ◽

10.1139/x85-082 ◽

1985 ◽

Vol 15 (3) ◽

pp. 498-504 ◽

Cited By ~ 19

Author(s):

Hans Nienstaedt

Keyword(s):

White Spruce ◽

Frost Damage ◽

Growth Potential ◽

Ottawa River ◽

Frost Injury ◽

Growth Initiation ◽

High Heritability ◽

Lake States ◽

Spring Frosts ◽

The Impact

White spruce progenies from the Lake States (61) and from the Ottawa River Valley, Ontario (31), were tested in north-central Wisconsin. Transplants were raised in nurseries in Wisconsin and Ontario and planted in 1969 in an open field after thorough weed control. Observations in the Wisconsin nursery and in the field between 1971 and 1979 are reported. They included heights, frost damage, spring vegetative growth phenology, strobili production, and three cone characteristics. The discussion concentrates on the relationships between heights and the other measured characteristics. Frost damage proved difficult to assess. In the year of frost, damage is severe, a 50% growth reduction, and the fastest growing trees are most severely damaged. However, in environments with only occasional late spring frosts, permanent damage is negligible. Spring growth initiation was not correlated significantly with total height growth or frost damage. Breeding of late-flushing genotypes that can avoid frost damage is questionable in spite of the high heritability for flushing. Female strobili production was substantial at age 10 years, male production was not. Even so, generation turnovers of 10–15 years may be possible. The impact of fecundity on growth potential is discussed as it relates to multigeneration breeding.

Download Full-text

Vegetative phenology in a clonal seed orchard of Piceaglauca and Piceamariana in northwestern Ontario

Canadian Journal of Forest Research ◽

10.1139/x82-058 ◽

1982 ◽

Vol 12 (2) ◽

pp. 408-413 ◽

Cited By ~ 15

Author(s):

Conor O'Reilly ◽

William H. Parker

Keyword(s):

Black Spruce ◽

White Spruce ◽

Seed Orchard ◽

Frost Damage ◽

Northern Ontario ◽

Spring Frost ◽

Growth Cessation ◽

Clonal Seed Orchard ◽

Qualitative Index ◽

Vegetative Phenology

The vegetative phenology of Piceaglauca (Moench) Voss and P. mariana (Mill.) B.S.P. was determined in 1979 based on four ramets selected from each of 14 clones of each species located at a seed orchard in northern Ontario. The time of flushing of the leaders and four lateral branches was determined by a qualitative index of bud and shoot development; time of growth cessation was scored as the date at which 95% of shoot growth was complete. The flushing of the vegetative buds of white spruce lasted for a 10-day period compared with only 6 days for black spruce. Although the average date of flushing for white spruce clones was 9 days ahead of the average date for black spruce clones, the latest white spruce clone flushed only 3 days before the earliest black spruce clones. As well, degree-day requirements for flushing were significantly different for clones within each of the two species. These results suggest that the selection of late-flushing white spruce trees for seed orchard stock has the potential to decrease spring frost damage in this species in northern Ontario. Date of budbreak was not correlated with date of growth cessation for either white or black spruce; however, early-flushing clones of black spruce produced significantly greater leader extension than late-flushing clones.

Download Full-text

On the relative attractions of sulphuric acid for water, under particular circumstances: with suggestion of means of improving the ordinary process of manufacturing sulphuric acid

Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London ◽

10.1098/rspl.1837.0040 ◽

1843 ◽

Vol 4 ◽

pp. 81-82

Keyword(s):

High Temperature ◽

Specific Gravity ◽

Sulphuric Acid ◽

Conclusive Evidence ◽

Dew Point ◽

Chemical Affinity ◽

Dilute Acid ◽

Atmospheric Air ◽

Open Atmosphere ◽

Series Of Experiments

The object of the inquiry detailed in the present paper is to determine at what degree of concentration the affinity of sulphuric acid for aqueous vapour is equal to that of anhydrous space for the same vapour at given temperatures. It has long been known that concentrated sulphuric acid abstracts moisture from the atmosphere, but the amount and the rate of this absorption have never been ascertained with accuracy; and consequently, in applying this acid to purposes of exsiccation, the experimenter has often been at a loss to know whether the acid was sufficiently strong to render the space in which it was confined perfectly anhydrous. By placing portions of the acid, previously weighed, and diluted with known quantities of water, under the receiver of an air-pump, with equal portions of concentrated acid, of the specific gravity 1·8428, in similar dishes, the author ascertained that the dilute acid could be concentrated to the specific gravity 1·814, at a temperature varying from 65° to 57°: whence he concludes that acid of such strength is capable of drying a vacuum when the temperature does not exceed 57°. By making similar experiments in air, the author compared together the weights lost by ten grains of dilute sulphuric acid of the specific gravity 1·135, at three different periods of the day for six days, taking note of the dew-point and the temperature; and infers that when the affinity of space for vapour, or the evaporating force, is equal to 0·15 of an inch of mercury, it is just able to balance the affinity for water of sulphuric acid of the specific gravity 1·249. The author next instituted a series of experiments to ascertain whether the evaporation of water from dilute sulphuric acid is capable of being carried on to the same extent in air as in vacuo, and found that the evaporating force of air exerted upon such acid is less than that of a vacuum at the same temperature. He observes that his experiments offer conclusive evidence that the evaporation of water is not owing to the existence of a chemical affinity between the vapour of the liquid and atmospheric air; but thinks that they favour the notion that the obstruction to this process in the open atmosphere is rather owing to the pressure than to the inertiæ of the particles of air. He is also of opinion that improvements will hereafter arise from this inquiry with regard to the economical management of the process of manufacturing sulphuric acid, which process would be greatly expedited by the regulated admission of steam into the condensing chambers kept at a constant high temperature.

Download Full-text

The effect of spring frosts on the nectar production and the bee visitation of fruit trees

International Journal of Horticultural Science ◽

10.31421/ijhs/6/1/75 ◽

2000 ◽

Vol 6 (1) ◽

Author(s):

P. Benedek ◽

J. Nyéki ◽

I. Amtmann ◽

F. Bakcsa ◽

J. Iváncsics ◽

...

Keyword(s):

Tree Species ◽

Fruit Trees ◽

Frost Damage ◽

Fruit Tree ◽

Wild Plants ◽

Cold Weather ◽

Nectar Production ◽

Spring Frost ◽

Fruit Orchards ◽

Spring Frosts

Fruit tree species suffered very strong spring frosts in 1997 in Hungary. This caused partial or total damages at buds and flowers depending on site and time of blooming. It was demonstrated at a number of experiments that frost and cold weather also strongly affected the nectar production of surviving flowers. No or very little amount of nectar was measured in flowers first of all of early blooming fruit tree species (apricot) but also of pear and apple in some places. In spite of this fact intensive honeybee visitation was detected in the flowers of fruit trees that suffered partial frost damage only at those sites where honeybee colonies were placed in or at the experimental plantations and the lack of sufficient amount of nectar did not affected bee behaviour seriously on fruit flowers. This means that bad nectar production failed to affect bee visitation of fruit trees definitely. The reason for this was the fact that not only fruit trees but another early bee plants (wild plants, too) suffered frost damage. Accordingly, in lack of forage bees intensively searched for food at blooming fruit trees with some living flowers. Consequently, there was an acceptable yield at those plantations where bud and flower damage was not complete. Accordingly, intensive bee visitation (that is moving additional bee colonies to overpopulate fruit orchards with honeybees) can be an effective tool to decrease or eliminate the detrimental effect of spring frost on the yield of fruit trees where bud or fruit damage is not too high.

Download Full-text

Serial Attention Mechanisms in Visual Search: A Direct Behavioral Demonstration

Journal of Cognitive Neuroscience ◽

10.1162/089892902320474454 ◽

2002 ◽

Vol 14 (7) ◽

pp. 980-993 ◽

Cited By ~ 33

Author(s):

Emanuela Bricolo ◽

Tiziana Gianesini ◽

Alessandra Fanini ◽

Claus Bundesen ◽

Leonardo Chelazzi

Keyword(s):

Visual Search ◽

Size Effects ◽

Conclusive Evidence ◽

Steady Increase ◽

Functional Neuroanatomy ◽

Set Size ◽

Behavioral Signatures ◽

Series Of Experiments ◽

The Individual ◽

Set Size Effects

In visual search, inefficient performance of human observers is typically characterized by a steady increase in reaction time with the number of array elements—the so-called set-size effect. In general, set-size effects are taken to indicate that processing of the array elements depends on limited-capacity resources, that is, it involves attention. Contrasting theories have been proposed to account for this attentional involvement, however. While some theories have attributed set-size effects to the intervention of serial attention mechanisms, others have explained set-size effects in terms of parallel, competitive architectures. Conclusive evidence in favor of one or the other notion is still lacking. Especially in view of the wide use of visual search paradigms to explore the functional neuroanatomy of attentional mechanisms in the primate brain, it becomes essential that the nature of the attentional involvement in these paradigms be clearly defined at the behavioral level. Here we report a series of experiments showing that highly inefficient search indeed recruits serial attention deployment to the individual array elements. In addition, we describe a number of behavioral signatures of serial attention in visual search that can be used in future investigations to attest a similar involvement of serial attention in other search paradigms. We claim that only after having recognized these signatures can one be confident that truly serial mechanisms are engaged in a given visual search task, thus making it amenable for exploring the functional neuro-anatomy underlying its performance.

Download Full-text

Spring frost damage to placental tissues in lowbush blueberry flower buds

Canadian Journal of Plant Science ◽

10.4141/p00-176 ◽

2001 ◽

Vol 81 (4) ◽

pp. 779-781 ◽

Cited By ~ 1

Author(s):

A. Randall ◽

Olson and Leonard J. Eaton

Keyword(s):

Key Words ◽

Fruit Set ◽

Frost Damage ◽

Full Bloom ◽

Flower Buds ◽

Vaccinium Angustifolium ◽

Spring Frost ◽

Lowbush Blueberry ◽

Commercial Yield ◽

Spring Frosts

Closed flower buds and flowers at full bloom of Vaccinium angustifolium Ait. were collected from the field and histologically examined after severe spring frosts. Prior to anthesis, blackened ovarian placentae in closed buds were the only damaged tissues evident; placental damage may interfere with both seed and fruit set. Undetected frost damaged placentae may contribute to losses in commercial yield. Key words: Vaccinium, frost damage, placenta

Download Full-text

A case of severe frost damage prior to budbreak in young conifers in Northeastern Ontario: Consequence of climate change?

The Forestry Chronicle ◽

10.5558/tfc85453-3 ◽

2009 ◽

Vol 85 (3) ◽

pp. 453-462 ◽

Cited By ~ 31

Author(s):

Rongzhou Man ◽

Gordon J Kayahara ◽

Qing-Lai Dang ◽

James A Rice

Keyword(s):

Climate Change ◽

Cold Hardiness ◽

Shoot Elongation ◽

Frost Damage ◽

Weather Data ◽

Climatic Warming ◽

Closed Canopy ◽

Time Requirements ◽

Spring Frosts ◽

Understory Trees

In spring 2007, young planted and natural conifers suffered extensive needle and bud injury near Hearst and Kapuskasing in northeastern Ontario. Damage was observed on all species of conifers up to 20 years old and 8 m in height. Taller trees, especially those in the overstory, and young understory trees protected by a closed canopy had less damage. The damage was caused by earlier than normal loss of cold hardiness followed by late spring frosts according to damage observations, weather station data, and calculated thermal time requirements for budbreak and cold hardiness of conifers. During May 19 to 21, 2007, minimum temperatures were recorded between -8°C and -9°C, and before this period, temperatures were warm enough to induce early dehardening and loss of trees' cold hardiness. According to the historical weather data for Kapuskasing, estimated budbreak time has become earlier since 1918 and freezing temperatures during budbreak and shoot elongation (between growing degree days 100 and June 15) have become more frequent since 1980. If the trend towards earlier budbreak is due to climate change, then the type of frost damage we observed in northeastern Ontario in 2007 could become more common. We discuss implications of such events and suggest research needed to understand the risk of frost damage with climatic warming and to reduce damage. Key words: conifer frost damage, mature needle and bud (or needle/bud) mortality, early dehardening and budbreak (or dehardening/budbreak), climatic warming

Download Full-text

PHENOLOGICAL AND CLIMATIC SIMULATION OF THE LATE FROST DAMAGE IN CHERRY AND SOUR CHERRY IN ROMANIA

Acta Horticulturae ◽

10.17660/actahortic.2006.707.13 ◽

2006 ◽

pp. 109-117

Author(s):

E. Chitu ◽

C. Paltineanu

Keyword(s):

Sour Cherry ◽

Frost Damage ◽

Late Frost

Download Full-text

Frost Damage to White Spruce Buds

Canadian Journal of Forest Research ◽

10.1139/x72-013 ◽

1972 ◽

Vol 2 (1) ◽

pp. 62-63 ◽

Cited By ~ 6

Author(s):

J. R. Clements ◽

J. W. Fraser ◽

C. W. Yeatman

Keyword(s):

Apical Meristem ◽

White Spruce ◽

Frost Damage ◽

Late Spring ◽

Time Of Death ◽

Spring Frost ◽

Late Spring Frost ◽

Understory Trees

Unopened buds of white spruce (Piceaglauca (Moench) Voss) were damaged by late spring frost. At time of death of the apical meristem the buds were not ready for flushing. As expected on the basis of ground frosts, there was more damage among shorter trees than among taller trees, and more damage among open-grown trees than among understory trees.

Download Full-text