Effect of Snow Removal on Typhula Blight Development at High Elevation Golf Courses in Colorado

2013 ◽  
Vol 14 (1) ◽  
pp. 12 ◽  
Author(s):  
Tamla Blunt ◽  
Tony Koski ◽  
Ned Tisserat
Keyword(s):  
Kentucky Bluegrass ◽  
High Elevation ◽  
Early Spring ◽  
Disease Suppression ◽  
Late Winter ◽  
Putting Greens ◽  
Freeze Avoidance ◽  
Snow Removal ◽  
Freeze Damage ◽  
High Elevations

Golf course superintendents at high elevations in Colorado apply fungicides in late October before permanent snow cover to suppress Typhula blight development. Many remove snow from putting greens in late winter or early spring assuming this practice helps suppress Typhula blight late into the snow season. They also remove snow to prevent ice formation and freeze damage to turfgrass during snowmelt. However, the benefits of spring snow removal in disease suppression and freeze avoidance have not been demonstrated in Colorado. We compared Typhula blight severity and turfgrass health in Kentucky bluegrass and annual bluegrass fairways where snow was removed weekly from late October through mid-November, from early- to mid-March until the end of the snow period, or not removed. Fall snow removal did not reduce Typhula blight severity compared to no snow removal, but it did result in freeze damage to annual, but not Kentucky bluegrass. Spring snow removal had no effect on Typhula blight severity or freeze damage. Thus the practice of snow removal was of no apparent benefit in our studies. Accepted for publication 3 June 2013. Published 21 August 2013.

scholarly journals (236) Evaluation of Styrax japonicus for Time of Budbreak and Susceptibility to Spring Freeze Damage

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1002B-1002 ◽  
Author(s):  
Sandra Reed
Keyword(s):  
United States ◽  
Genetic Variability ◽  
Weather Conditions ◽  
The United States ◽  
Early Spring ◽  
Late Winter ◽  
Ornamental Tree ◽  
Good Consistency ◽  
Spring Temperatures ◽  
Freeze Damage

Japanesesnowbell(Styrax japonicus Sieb. & Zucc.) is an outstanding small ornamental tree that is underutilized in the United States. Many of the cultivars of this Asian native frequently suffer spring freeze damage, especially when grown in the areas of the country that routinely experience dramatic fluctuations in late winter and early spring temperatures. The objectives of this study were to determine if there was variability within S. japonicus for time of budbreak and if this variability could be used for selecting plants with reduced susceptibility to spring freeze damage. In 1998, 224 open-pollinated seedlings were planted in the field. Percent budbreak was evaluated weekly during a 6-week period in Spring 1999 and 2000. While weather conditions varied greatly between the 2 years, there was good consistency between mean budbreak ratings in 1999 and 2000. There was a 4-week difference between the earliest and latest plants to break dormancy. Based on the 1999 and 2000 data, 28 plants were selected and propagated. A replicated trial involving these selections and three cultivars was carried out in 2002, 2003, and 2004. All of the selections broke bud later and suffered less freeze damage than `Emerald Pagoda' and `Carillon', but many performed similarly to `Pink Chimes'. Variation in height, width, caliper, and canopy shape was observed among the selections. There is an opportunity to utilize the genetic variability in S. japonicus for developing cultivars with reduced susceptibility to spring freeze damage.

WINTER CROWN ROT OR SNOW MOLD OF ALFALFA, CLOVERS, AND GRASSES IN ALBERTA: I. OCCURRENCE, PARASITISM, AND SPREAD OF THE PATHOGEN

1948 ◽  
Vol 26c (1) ◽  
pp. 71-85 ◽  
Author(s):  
M. W. Cormack
Keyword(s):  
Red Clover ◽  
Kentucky Bluegrass ◽  
Early Spring ◽  
Crown Rot ◽  
Wild Plants ◽  
Late Winter ◽  
Meadow Fescue ◽  
Snow Mold ◽  
Red Fescue ◽  
Radial Spread

Winter crown rot or snow mold of alfalfa, clovers, and grasses, caused by an unidentified low-temperature basidiomycete, is widespread and often of major importance in the central and northern areas of Alberta and Saskatchewan. For example, during a six year period an average of 62% of the alfalfa stands examined in west-central Alberta were affected, and the average estimated damage was 10%. Severe damage also occurs in alsike and white Dutch clover, and in timothy, red top, and creeping red fescue. The disease is less prevalent in red clover, Kentucky bluegrass, and meadow fescue, and seldom occurs in brome grass, crested wheat grass, and slender wheat grass. Iris and other garden perennials, as well as dandelion, quack grass, and various wild plants are also damaged.The pathogen attacks the dormant plants beneath the snow during the first thaw in the late winter or early spring. The plants are killed or weakened in irregular patches as the result of rotting of the crown buds and tissues. These symptoms are distinct from those of true winter killing, with which the damage has been confused. The pathogen is difficult to isolate, except at a temperature near freezing from superficial mycelium or freshly infected tissues.The results of infection experiments in the field and under controlled conditions indicate that the development of the disease is associated with physiological changes in the host. Inoculated alfalfa plants brought inside at weekly intervals became susceptible at dates varying from late November to late December in different seasons. Infection was most severe under the conditions provided by a slowly melting snow cover and was also influenced by soil temperature, soil moisture, and growth of the pathogen.The pathogen appears to spread mainly by means of mycelium, since no sporulating stage has been found. The mycelium spreads both above and below ground at the time of the first spring thaw. The distance of radial spread, as measured by killing of the plants, varied in different years from 2.7 to 7.5 in. in dense alfalfa stands, and from 0. 5 to 6.0 in. in bare land.

scholarly journals Variation among Highbush Blueberry Cultivars for Frost Tolerance of Open Flowers

HortScience ◽  
2013 ◽  
Vol 48 (6) ◽  
pp. 692-695 ◽  
Author(s):  
Lisa J. Rowland ◽  
Elizabeth L. Ogden ◽  
Fumiomi Takeda ◽  
David Michael Glenn ◽  
Mark K. Ehlenfeldt ◽  
...  
Keyword(s):  
Frost Tolerance ◽  
Early Spring ◽  
Late Winter ◽  
Highbush Blueberry ◽  
Fruit Crops ◽  
Lethal Temperature ◽  
Genotype Effect ◽  
Freeze Damage ◽  
Whole Plants ◽  
Spring Frosts

Injury of open flowers often occurs in fruit crops by late winter or early spring frosts and can result in significant reduction in yield. In this study, freezing tolerance of open flowers of five highbush blueberry cultivars, Bluecrop, Elliott, Hannah’s Choice, Murphy, and Weymouth, was determined using two freezing methods. Methods involved either placing whole plants in a radiation frost chamber or detached shoots in a glycol-freezing bath. In both methods, plants (or excised shoots) with opening flowers were exposed to temperatures ranging from –2 to –10 °C. After freeze treatments, several flower parts were evaluated for damage and the lethal temperature50 (LT50) determined. In order, from the most sensitive flower part to the least sensitive on average, were the corolla, filament, anther, style, exterior ovary, stigma, ovules, interior ovary, and placenta. A two-way analysis of variance (ANOVA) found no significant effect of the freezing method on the calculated freeze damage to most of the various flower parts. However, a significant genotype effect was found on freeze damage to the style, filament, anthers, and exterior ovary. Overall, ‘Bluecrop’ was the most sensitive to freezing, whereas ‘Hannah’s Choice’ and ‘Murphy’ were the most freezing-tolerant. In conclusion, genotypic variability in frost tolerance of open highbush blueberry flowers was detected, which can be exploited in breeding for more frost-tolerant cultivars.

Proposed mechanisms of initial injury-causing apical dieback in red spruce at high elevation in eastern North America

1986 ◽  
Vol 16 (5) ◽  
pp. 1113-1116 ◽  
Author(s):  
Lance S. Evans
Keyword(s):  
Tissue Injury ◽  
Normal Growth ◽  
High Elevation ◽  
Early Spring ◽  
Red Spruce ◽  
Late Winter ◽  
Visible Injury ◽  
Chlorotic Mottle ◽  
Initial Injury ◽  
Whiteface Mountain

Observations of apical dieback and tree declines of high-elevation red spruce (Picearubens Sarg.) were made from hundreds of random plant samples that exhibited recent injury. This recent and predominant injury related to red spruce decline was not a result of secondary injury to other tissues. Samples of recently injured branches were collected on Whiteface Mountain, NY, Mount Mitchell, NC, and Clingman's Dome, TN. Visible recent injury at Whiteface Mt. was much more intensive and extensive than at Mt. Mitchell. Moreover, few symptoms were present at Clingman's Dome. In the normal growth pattern of red spruce, three buds elongate from each twig terminus during spring. These buds elongate the next growing season and three new buds will form on each of the three elongated twigs. During late winter and early spring of 1985, recent tissue injury occurred on twigs that elongated during the spring of 1984. This recent twig injury and necrosis occurred on 1st-year twigs that retained injured or necrotic needles. No bud enlargement occurred on affected 1st-year twigs. Injury to only one or two of the 1st-year twigs on a branch was the most common injury symptom observed, while injury to all three 1st-year twigs on a branch was rare. On a branch with one or two injured 1st-year twigs, adjacent 1st-year twigs on the same branch had no visible injury. In addition to having all needles of affected twigs exhibiting the same degree of injury simultaneously, injury and necrosis of all portions of affected needles occurred simultaneously. In this manner, affected tissues (twigs and needles) on a branch exhibited a uniform appearance of injury. There was no chlorotic mottle or bands of living and necrotic tissues that has been described for conifer needles exposed to gaseous air pollutants. These results are discussed in relation to possible causes.

scholarly journals Protecting Blueberries from Freezes in Florida

EDIS ◽  
1969 ◽  
Vol 2004 (7) ◽  
Author(s):  
Paul M. Lyrene ◽  
Jeffrey G. Williamson
Keyword(s):  
Early Spring ◽  
Cooperative Extension Service ◽  
Late Winter ◽  
Publication Date ◽  
Highbush Blueberry ◽  
University Of Florida ◽  
Frost Injury ◽  
Early Ripening ◽  
Freeze Damage ◽  
Southern Highbush

Blueberries bloom in late winter or early spring in Florida, making the flowers and young fruit highly susceptible to freeze and frost injury. Killing freezes can occur as late as mid to late March throughout much of Florida, long after the initiation of bloom, especially for early-ripening southern highbush blueberry cultivars. This publication describes conditions that often occur in commercial blueberry fields during and after bloom when the potential for freeze damage exists. Practices that growers can use to minimize freeze damage are also discussed. This document is HS968, one of a series of the Department of Horticultural Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: May 2004.  HS968/HS216: Protecting Blueberries from Freezes in Florida (ufl.edu)

scholarly journals Does Hyperoxia Restrict Pyrenean Rock Lizards Iberolacerta bonnali to High Elevations?

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 200
Author(s):  
Eric J. Gangloff ◽  
Sierra Spears ◽  
Laura Kouyoumdjian ◽  
Ciara Pettit ◽  
Fabien Aubret
Keyword(s):  
High Elevation ◽  
Conservation Strategy ◽  
The Novel ◽  
Thermal Physiology ◽  
Treatment Groups ◽  
Thermal Performance Curve ◽  
And Performance ◽  
Thermal Preferences ◽  
High Elevations ◽  
Intense Radiation

Ectothermic animals living at high elevation often face interacting challenges, including temperature extremes, intense radiation, and hypoxia. While high-elevation specialists have developed strategies to withstand these constraints, the factors preventing downslope migration are not always well understood. As mean temperatures continue to rise and climate patterns become more extreme, such translocation may be a viable conservation strategy for some populations or species, yet the effects of novel conditions, such as relative hyperoxia, have not been well characterised. Our study examines the effect of downslope translocation on ectothermic thermal physiology and performance in Pyrenean rock lizards (Iberolacerta bonnali) from high elevation (2254 m above sea level). Specifically, we tested whether models of organismal performance developed from low-elevation species facing oxygen restriction (e.g., hierarchical mechanisms of thermal limitation hypothesis) can be applied to the opposite scenario, when high-elevation organisms face hyperoxia. Lizards were split into two treatment groups: one group was maintained at a high elevation (2877 m ASL) and the other group was transplanted to low elevation (432 m ASL). In support of hyperoxia representing a constraint, we found that lizards transplanted to the novel oxygen environment of low elevation exhibited decreased thermal preferences and that the thermal performance curve for sprint speed shifted, resulting in lower performance at high body temperatures. While the effects of hypoxia on thermal physiology are well-explored, few studies have examined the effects of hyperoxia in an ecological context. Our study suggests that high-elevation specialists may be hindered in such novel oxygen environments and thus constrained in their capacity for downslope migration.

scholarly journals Protective Role of Ice Barriers: How Reproductive Organs of Early Flowering and Mountain Plants Escape Frost Injuries

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1031
Author(s):  
Clara Bertel ◽  
Jürgen Hacker ◽  
Gilbert Neuner
Keyword(s):  
Management Strategies ◽  
Woody Species ◽  
Reproductive Organs ◽  
High Elevation ◽  
Protective Role ◽  
Early Spring ◽  
Early Flowering ◽  
Ice Formation ◽  
Species Vulnerability ◽  
Infrared Video

In the temperate zone of Europe, plants flowering in early spring or at high elevation risk that their reproductive organs are harmed by episodic frosts. Focusing on flowers of two mountain and three early-flowering colline to montane distributed species, vulnerability to ice formation and ice management strategies using infrared video thermography were investigated. Three species had ice susceptible flowers and structural ice barriers, between the vegetative and reproductive organs, that prevent ice entrance from the frozen stems. Structural ice barriers as found in Anemona nemorosa and Muscari sp. have not yet been described for herbaceous species that of Jasminum nudiflorum corroborates findings for woody species. Flowers of Galanthus nivalis and Scilla forbesii were ice tolerant. For all herbs, it became clear that the soil acts as a thermal insulator for frost susceptible below ground organs and as a thermal barrier against the spread of ice between individual flowers and leaves. Both ice barrier types presumably promote that the reproductive organs can remain supercooled, and can at least for a certain time-period escape from effects of ice formation. Both effects of ice barriers appear significant in the habitat of the tested species, where episodic freezing events potentially curtail the reproductive success.

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

TEMPERATURE RESISTANCE OF GOLDFISH MAINTAINED UNDER CONTROLLED PHOTOPERIODS

1959 ◽  
Vol 37 (4) ◽  
pp. 419-428 ◽  
Author(s):  
William S. Hoar ◽  
G. Beth Robertson
Keyword(s):  
Temperature Change ◽  
Seasonal Variations ◽  
Rapid Growth ◽  
Endocrine System ◽  
Early Spring ◽  
Late Winter ◽  
Thyroid Activity ◽  
Temperature Resistance ◽  
Sudden Temperature Change

Goldfish maintained under controlled photoperiods for 6 weeks or longer were relatively more resistant to a sudden elevation in temperature when the daily photoperiods had been long (16 hours) and relatively more resistant to sudden chilling when they had been short (8 hours). The magnitude of the effect varied with the season. Thyroid activity was slightly greater in fish maintained under the shorter photoperiods. The longer photoperiods stimulated more rapid growth of ovaries during late winter and early spring. The endocrine system is considered a link in the chain of events regulating seasonal variations in resistance to sudden temperature change.

Leaf spot and dry rot of lettuce caused by Xanthomonas vitians (Brown) Dowson

1963 ◽  
Vol 14 (6) ◽  
pp. 778 ◽  
Author(s):  
DE Harrison
Keyword(s):  
Leaf Spot ◽  
Early Spring ◽  
Late Winter ◽  
Laboratory Studies ◽  
Dry Rot ◽  
Complete Destruction ◽  
Western Victoria ◽  
Valley Area ◽  
North Western

During the late winter and early spring of 1960, and again to a lesser extent in 1961 and 1962, many lettuce crops in the Murray Valley area of north-western Victoria were seriously affected by a disease characterized by blackening, dry rotting, and collapse of the affected leaves. The incidence of disease varied from about 10% up to practically complete destruction of some plantings. A yellow bacterium was consistently isolated from affected plants and proved to be pathogenic to lettuce. Laboratory studies have shown that the organism agrees closely with the recorded description of Xanthomonas vitians (Brown) Dowson, which has not, apparently, been previously studied in Australia.

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