THE DEVELOPMENT OF FOLIAR SYMPTOMS AND THE POSSIBLE CAUSE AND ORIGIN OF WHITE PINE NEEDLE BLIGHT

1960 ◽  
Vol 38 (2) ◽  
pp. 153-161 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Local Population ◽  
Early Summer ◽  
Pine Needle ◽  
White Pine ◽  
Growing Seasons ◽  
Foliar Symptoms ◽  
Leaf Tissues ◽  
The Individual ◽  
Possible Cause ◽  
Needle Blight

Needle blight of eastern white pine (Pinus strobus L.) is characterized by an orange-red discoloration of the distal portions of current year needles. At Chalk River, Ontario, 600 seedlings and saplings of white pine were examined repeatedly throughout the 1957 and 1958 growing seasons for the appearance and development of needle blight symptoms. The first of these were faint pinkish spots on the stomata-bearing faces of needles in semimature (about four-week-old) tissue. These developed rapidly into orange-red bands which within a few days spread to the needle tips. Mature tissue was not susceptible to attack, so lesions which developed subsequently were always proximal, on younger tissues derived from basal meristems. Attacks which occurred in the early summer killed only limited areas at the tips of needles, whereas those that occurred when the needles were nearly full-grown involved most of their length. Needle blight incidence was confined to a few major outbreaks during one season and in each of these many trees developed typical symptoms at essentially the same time. Each of these major outbreaks of the disease occurred after 1 or more days of wet weather which was followed suddenly by a continuous sunny period. No microorganisms were isolated from tissues displaying the initial needle blight symptoms.The data with respect to the nature and occurrence of needle blight are believed to suggest that susceptibility to the unfavorable conditions which incite it is inherent in the individual and that differences in response among members of a local population depend on variations in susceptibility, rather than on a varying local predisposition among uniformly susceptible individuals. The blight is initiated in semimature leaf tissues only but then spreads distally throughout adjacent, more mature tissues with a similar pattern of breakdown.

The annual occurrence and effects of semimature-tissue needle blight on white pine

1971 ◽  
Vol 49 (3) ◽  
pp. 423-435
Author(s):  
S. N. Linzon
Keyword(s):  
Adverse Effects ◽  
Similar Pattern ◽  
Pinus Strobus ◽  
Premature Death ◽  
White Pine ◽  
Eastern White Pine ◽  
Foliar Symptoms ◽  
Needle Blight

The occurrence of semimature-tissue needle blight (SNB) on eastern white pine (pinus strobus L.) was closely followed for 7 years, 1957 to 1963. White pines susceptible to SNB displayed recurrent foliar symptoms in some years. Annual fluctuations in the incidence of SNB occurred in a similar pattern on widely separated sample plots in a localized area. Major outbreaks of SNB were infrequent and were often found to occur during a continuous sunny period following a period of excess rainfall. The adverse effects of the disease on foliage were reflected in reduced growth in other parts of affected trees and in premature death of perennially blighted trees.

FIELD GRAFTING WITH HEALTHY AND NEEDLE-BLIGHTED EASTERN WHITE PINE TREES AND THE EXPRESSION OF DISEASE SYMPTOMS

1961 ◽  
Vol 39 (6) ◽  
pp. 1287-1292 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Pinus Strobus ◽  
White Pine ◽  
Stages Of Development ◽  
Eastern White Pine ◽  
Disease Symptoms ◽  
Pine Trees ◽  
Root Grafts ◽  
The Individual ◽  
Needle Blight ◽  
Made In

Healthy and needle-blighted eastern white pine trees (Pinus strobus L.) were intergrafted in the forest using bottle and cleft crown graft techniques. The grafts were made in four combinations of diseased and healthy scions and stock branches and at three different stages of development of the graft components. High percentages of successful grafts were obtained when the partner combinations included healthy scions and when the grafting was done in early May with active top growth just beginning in both scions and stock. Fewer grafts survived when diseased scions were employed and when the field grafting was carried out with dormant-collected scions or with scions and stock both possessing advanced new growth.Each grafted partner retained its original identity. Needle-blight symptoms appeared simultaneously on diseased scions and their mother trees, while the healthy stock trees remained unaffected. Conversely, healthy scions and their mother trees were unaffected while the diseased stock trees displayed the needle-blight symptoms on their foliage. No disease symptoms were transmitted by stem grafting. A search revealed that perennially needle-blighted trees were joined to neighboring healthy trees by natural root grafts, and that there was no visible communication of the disease symptoms. Additional evidence has been presented to show that needle blight is nonparasitic in etiology and that susceptibility to needle breakdown is inherent in the individual.

Some Effects of Oxidant Air Pollutants (Ozone and Peroxyacetyl Nitrate) on the Ultrastructure of Leaf Tissues

1972 ◽  
Vol 30 ◽  
pp. 360-361
Author(s):  
William W. Thomson ◽  
Elizabeth S. Swanson
Keyword(s):  
Air Pollutants ◽  
Electron Microscopic Examination ◽  
Peroxyacetyl Nitrate ◽  
Electron Microscopic ◽  
Growth Physiology ◽  
Physiology And Biochemistry ◽  
Entire Plant ◽  
Leaf Tissues ◽  
Gaseous Hydrocarbons ◽  
The Individual

The oxidant air pollutants, ozone and peroxyacetyl nitrate, are produced in the atmosphere through the interaction of light with nitrogen oxides and gaseous hydrocarbons. These oxidants are phytotoxicants and are known to deleteriously affect plant growth, physiology, and biochemistry. In many instances they induce changes which lead to the death of cells, tissues, organs, and frequently the entire plant. The most obvious damage and biochemical changes are generally observed with leaves.Electron microscopic examination of leaves from bean (Phaseolus vulgaris L.) tobacco (Nicotiana tabacum L.) and cotton (Gossipyum hirsutum L.) fumigated for .5 to 2 hours with 0.3 -1 ppm of the individual oxidants revealed that changes in the ultrastructure of the cells occurred in a sequential fashion with time following the fumigation period. Although occasional cells showed severe damage immediately after fumigation, the most obvious change was an enhanced clarity of the cell membranes.

An integrated approach for tracking climate-driven changes in treeline environments on different time scales in the Valle d’Aosta, Italian Alps

The Holocene ◽  
2021 ◽  
pp. 095968362110259
Author(s):  
Anna Masseroli ◽  
Giovanni Leonelli ◽  
Umberto Morra di Cella ◽  
Eric P Verrecchia ◽  
David Sebag ◽  
...  
Keyword(s):  
Integrated Approach ◽  
Early Summer ◽  
Ice Age ◽  
Limiting Factor ◽  
Alpine Treeline ◽  
Growing Seasons ◽  
Direct Measurements ◽  
Soil Temperatures ◽  
Summer Temperatures ◽  
Local Station

Both biotic and abiotic components, characterizing the mountain treeline ecotone, respond differently to climate variations. This study aims at reconstructing climate-driven changes by analyzing soil evolution in the late Holocene and by assessing the climatic trends for the last centuries and years in a key high-altitude climatic treeline (2515 m a.s.l.) on the SW slope of the Becca di Viou mountain (Aosta Valley Region, Italy). This approach is based on soil science and dendrochronological techniques, together with daily air/soil temperature monitoring of four recent growing seasons. Direct measurements show that the ongoing soil temperatures during the growing season, at the treeline and above, are higher than the predicted reference values for the Alpine treeline. Thus, they do not represent a limiting factor for tree establishment and growth, including at the highest altitudes of the potential treeline (2625 m a.s.l.). Dendrochronological evidences show a marked sensitivity of tree-ring growth to early-summer temperatures. During the recent 10-year period 2006–2015, trees at around 2300 m a.s.l. have grown at a rate that is approximately 1.9 times higher than during the 10-year period 1810–1819, one of the coolest periods of the Little Ice Age. On the other hand, soils show only an incipient response to the ongoing climate warming, likely because of its resilience regarding the changeable environmental conditions and the different factors influencing the soil development. The rising air temperature, and the consequent treeline upward shift, could be the cause of a shift from Regosol to soil with more marked Umbric characteristics, but only for soil profiles located on the N facing slopes. Overall, the results of this integrated approach permitted a quantification of the different responses in abiotic and biotic components through time, emphasizing the influence of local station conditions in responding to the past and ongoing climate change.

Rare forest types in northeastern Ontario: a classification and analysis of representation in protected areas

2010 ◽  
Vol 40 (3) ◽  
pp. 423-435 ◽  
Author(s):  
Charles R. Drever ◽  
James Snider ◽  
Mark C. Drever
Keyword(s):  
Protected Areas ◽  
Local Population ◽  
Red Oak ◽  
Betula Alleghaniensis ◽  
White Pine ◽  
Yellow Birch ◽  
Eastern White Pine ◽  
Habitat Specificity ◽  
White Cedar ◽  
Eastern White Cedar

Our objective was to assess the relative rarity and representation within protected areas of Standard Forest Units (SFUs) in northeastern Ontario by applying the concepts of geographic range, habitat specificity, and local population size. SFUs are stand type classifications, routinely employed by forest managers, based on tree composition, disturbance history, and prescribed silvicultural system. We identified several SFUs as rare because of a narrow distribution, association with only one landform type, or lack of at least one stand larger than an ecoregion-specific threshold. In the Boreal forest, rare SFUs comprised stands dominated by eastern hemlock ( Tsuga canadensis (L.) Carrière), red oak ( Quercus rubra L.), yellow birch ( Betula alleghaniensis Britt.), or eastern white-cedar ( Thuja occidentalis L.). Rare SFUs also included eastern white pine ( Pinus strobus L.) and (or) red pine ( Pinus resinosa Ait.) leading stands managed by shelterwood or seed tree silviculture as well as low-lying deciduous stands and selection-managed stands of shade-tolerant species. In the Great Lakes – St. Lawrence forest, rare SFUs were yellow birch stands, stands dominated by conifer species abundant in the Boreal, and shelterwood-managed hardwood stands. Several rare SFUs had <12% of their total area in protection, i.e., stands dominated by eastern white pine, yellow birch, eastern white pine – red oak, or eastern white-cedar. These rare stand types require increased protection in reserves and tailored silvicultural practices to maintain their probability of persistence.

scholarly journals Abnormal Leaf Development on White Oaks Linked to Drift of Chloroacetamide Herbicides

2005 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Jayesh B. Samtani ◽  
John B. Masiunas ◽  
James E. Appleby
Keyword(s):  
Central Region ◽  
Leaf Development ◽  
North Central Region ◽  
White Oak ◽  
North Central ◽  
The North ◽  
Leaf Tissues ◽  
Herbicide Drift ◽  
Possible Cause ◽  
Insect Attack

In the last few decades, white oak in the north central region have developed malformed spring leaves called “leaf tatters.” Symptoms begin with the death of interveinal leaf tissues, eventually leaving only the main leaf veins with little interveinal tissues present. Winter injury, frost, insect attack, and herbicide drift were all thought to be possible causes of leaf tatters. This study indicates that drift of chloroacetamide herbicides from applications onto corn and soybean fields is a possible cause of the leaf tatters syndrome. Accepted for publication 14 February 2005. Published 21 February 2005.

scholarly journals Changes in Number and Weight of Wheat and Triticale Grains to Manipulation in Source-Sink Relationship

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
E. Ballesteros-Rodríguez ◽  
C. G. Martínez-Rueda ◽  
E. J. Morales-Rosales ◽  
G. Estrada-Campuzano ◽  
G. F. González
Keyword(s):  
Yield Components ◽  
Genetic Improvement ◽  
Wheat Cultivar ◽  
Experimental Manipulation ◽  
Grain Weight ◽  
Agricultural Technology ◽  
Growing Seasons ◽  
Yield And Yield Components ◽  
The Individual ◽  
Source Sink

The source-sink ratio experimental manipulation has helped to define whether a crop is limited by source or sink or co-limited by both. There is no evidence in triticale of source-sink manipulations effects on yield and yield components. Two experiments were accomplished during 2008 and 2009 growing seasons at the Universidad Autónoma del Estado de México, México, and one in 2010 at the National Institute of Agricultural Technology in Pergamino, Argentina. Two triticale cultivars (line 4 and 7) and one wheat cultivar (Tollocan) were used. Source-sink relations were modified at anthesis by thinning, degraining, shading, and total defoliation procedures. Changes in the source-sink relation affected yields in both species differentially. The changes in yield due to cultivars and treatments were explained mainly by the number of grains rather than by their individual grain weight. The number of grains was affected by all treatments in both species, while the individual grain weight was increased by thinning and degraining mainly in triticale. A greater number of fertile florets in triticale were associated with their higher rate of abortion compared to wheat. These results could help to better understand crop management and genetic improvement.

Boron and Magnesium Fertilization of a Coastal Douglas-Fir Plantation

1993 ◽  
Vol 8 (2) ◽  
pp. 48-53 ◽  
Author(s):  
R. N. Green ◽  
R. E. Carter
Keyword(s):  
Height Growth ◽  
Douglas Fir ◽  
Boron Deficiency ◽  
Growing Seasons ◽  
Foliar Symptoms ◽  
Foliar Concentrations ◽  
A Site ◽  
Coastal British Columbia ◽  
Severe Growth

Abstract This study examines the role of boron and magnesium nutrition in the occurrence of severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Skwawka River valley of south coastal British Columbia. Four fertilizer treatments including boron (2.25 kg B/ha), magnesium (42 kg Mg/ha), boron plus magnesium, and a control, were applied in conjunction with planting on a site believed to be deficient in these nutrients. After 5 growing seasons, only treatments containing boron (B and B+Mg) showed improved height growth over the control trees. The incidence of leader dieback, swollen leading shoots, and foliage distortion was significantly related to treatment with virtually no occurrence in plots treated with boron. Seedling uptake of applied boron was high, with foliar concentrations of 45 ppm found after the second growing season. Foliar B levels declined to 13-15 ppm after 5 growing seasons. No significant increase in foliar magnesium levels was detected for either of the magnesium treatments. The reduction in the incidence of leader dieback and shoot and foliar symptoms in seedlings treated with B indicate that these symptoms were the result of boron deficiencies. This is the first study to verify boron deficiency in coastal Douglas-fir through fertilizer trials. West. J. Appl. For. 8(2):48-53.

Surface burning in a mature stand of Pinus resinosa and Pinus strobus in Michigan: effects on understory vegetation

2001 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
David D. Neumann ◽  
Donald I. Dickmann
Keyword(s):  
Late Summer ◽  
Pinus Resinosa ◽  
Red Pine ◽  
Phytolacca Americana ◽  
Vegetative Cover ◽  
White Pine ◽  
Periodic Surface ◽  
Surface Fires ◽  
Growing Seasons ◽  
Surface Burning

Beginning in 1991, periodic surface fires (frontal fire intensities <200 kW m–1) were introduced into a mixed red pine (Pinus resinosa Ait.) and white pine (P. strobus L.) plantation (dbh 16–60 cm). Replicated plots of 0.4–0.5 ha were either burned three times at biennial intervals (early May of 1991, 1993, and 1995), burned once (early May 1991), or not burned. Measurements were conducted during the 1994 and 1995 growing seasons. The pine overstory was largely unaffected by the fires. The understory on unburned plots contained 16 111 large seedlings (>1 m, ≤ 1.9 cm dbh) and 3944 saplings (2.0–5.9 cm dbh) per ha, consisting of 23 woody angiosperm taxa. Plots burned once contained 60% of the large seedlings, 7% of the saplings, and 6 fewer taxa than unburned plots. No large seedlings and few saplings were found in plots burned biennially. Cover of low (<1 m) woody and herbaceous vegetation in plots burned once or three times was twice that of unburned plots, even in the growing season immediately following the May 1995 re-burn. Recovery of low vegetative cover in the re-burned plots was rapid, exceeding that in once-burned or unburned plots by late summer following the burn. Species richness of low vegetation was 20–25% higher in burned than unburned plots, except in the year immediately following reburning. Taxa dominating this site following burning were Sassafras albidum (Nutt.) Nees, Rubus spp., Phytolacca americana L., and Dryopteris spinulosa (O.F. MÜll.) Watt. Restoration of low-intensity surface fires to ecosystems dominated by mature red pine or white pine is feasible, but major changes in understory structure and composition will occur.

VEGETATIVE PROPAGATION OF CONIFERS: XII. EFFECTS OF MEDIA, TIME OF COLLECTION, AND INDOLYLACETIC ACID TREATMENT ON THE ROOTING OF WHITE PINE AND WHITE SPRUCE CUTTINGS

1942 ◽  
Vol 20c (4) ◽  
pp. 204-211 ◽  
Author(s):  
J. L. Farrar ◽  
N. H. Grace
Keyword(s):  
Acid Treatment ◽  
White Spruce ◽  
Early Summer ◽  
Appreciable Effect ◽  
White Pine ◽  
Indolylacetic Acid ◽  
Sphagnum Peat ◽  
Effects Of Media ◽  
Phytohormone Treatment ◽  
Rooting Response

Semimonthly collections of white pine and white spruce cuttings were taken from July to October, 1939, and propagated in several media. Collections of both species were taken in late October to examine the effect of type of cutting and of planting in media involving different proportions of two sands and two different peats. Cuttings were dusted with a series of concentrations of indolylacetic acid in talc. The season of collection and the medium used for propagation were the factors of main importance. Phytohormone treatment failed to demonstrate appreciable effect, no difference in rooting response could be attributed to the kind of sand used, but there were indications that response increased with the amount of sedge peat in the medium.Rooting of white pine cuttings collected in late August and propagated in a sedge peat medium was 62%, earlier and later collections gave substantially less rooting. Sand only and the sphagnum peat media were generally inferior to the sedge type of peat. At the optimum season of collection the sphagnum peat effected 50% rooting.The late July collection of white spruce cuttings effected rooting of 90% of the plain cuttings when propagation occurred in a sedge peat medium. Low percentages rooted in sand or sphagnum peat media. Cuttings with a heel of old wood tended to be superior to plain cuttings in respect to survival and rooting.Preliminary experiments with spring and early summer collections of both species resulted in slight rooting. Likewise, greenhouse propagations of dormant material gave very poor results.

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