DESCRIPTION OF SEMIMATURE TISSUE OF EASTERN WHITE PINE FOLIAGE SUSCEPTIBLE TO NEEDLE BLIGHT

1962 ◽  
Vol 40 (8) ◽  
pp. 1175-1176 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
White Pine ◽  
Eastern White Pine ◽  
Needle Blight

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.

HISTOLOGICAL STUDIES OF SYMPTOMS IN SEMIMATURE-TISSUE NEEDLE BLIGHT OF EASTERN WHITE PINE

1967 ◽  
Vol 45 (1) ◽  
pp. 133-143 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Pinus Strobus ◽  
Pine Needles ◽  
The Other ◽  
White Pine ◽  
Eastern White Pine ◽  
Histological Studies ◽  
Endodermal Cells ◽  
Needle Blight

The incipient symptoms of needle blight of eastern white pine (Pinus strobus L.) appear only in semimature tissues of current year needles, and the orange-red lesions then spread acropetally throughout adjacent, more mature, tissues. Semimature tissue of white pine needles is characterized by the start of the suberization of the radial and transverse walls of the endodermal cells. The first cells to break down in blighted semimature tissue occur in the mesophyll region of one of the ventral faces of the needle. Mesophyll necrosis spreads laterally to the other ventral face and finally to the dorsal face of the needle, before proceeding distally through mature tissue. Anatomical differences exist between needles collected from susceptible and non-susceptible white pines.

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.

Etiological studies on needle fungi associated with semimature-tissue needle blight of eastern white pine

1968 ◽  
Vol 46 (12) ◽  
pp. 1565-1574 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Bordeaux Mixture ◽  
Growing Season ◽  
Morphological Development ◽  
White Pine ◽  
Eastern White Pine ◽  
Saprophytic Fungi ◽  
Disease Symptoms ◽  
First Occurrence ◽  
Spore Trapping ◽  
Needle Blight

The results of etiological studies on semimature-tissue needle blight (SNB) of eastern white pine (Pinus strobus L.) deny any role to needle fungi as the primary cause. No mycelium was found in newly blighted semimature tissue by either cultural or histological methods. Mycelia of several saprophytic fungi were isolated from the blighted portions of current year needles about 2 weeks after the onset of SNB, and fruit-bodies of different organisms were found to occur both in the interior and on the exterior of blighted needles about 4 weeks after the first occurrence of disease symptoms. The fruit-bodies of two Ascomycetes, Cenangium acuum Peck & Cooke and Hypoderma desmazierii Duby (= Lophodermium brachysporum (Rostrup) Tub.), were found on the necrotic terminals of attached 1-year-old needles which had been blighted in the previous year. The morphological development of apothecia of C. acuum was studied. Hysterothecia of Lophodermium spp. (L. pinastri (Schrad. ex Fr.) Chev. and L. nitens Darker) occurred ubiquitously on fallen white pine needles. Aerial spore trapping snowed that ascospores of C. acuum were abundant, those of Lophodermium spp. were prevalent, and those of H. desmazierii were practically non-existent in the area investigated. There was little coincidence between the occurrence of SNB outbreaks and peak populations of air-borne ascospores of these fungi. Ascospore suspensions and needles bearing fructifications of C. acuum and Lophodermium spp. were used to inoculate the newly developing needles of SNB-susceptible and non-susceptible field trees and potted seedlings, but the typical symptoms of SNB did not develop as a result of these inoculations. Two fungicides, captan and Bordeaux mixture, were applied to SNB-susceptible and non-susceptible field trees throughout the growing season, but neither fungicide prevented the symptoms of SNB from appearing on the new needles of susceptible trees at the same time as they appeared on untreated susceptible trees in the area. The fungicidal sprays, however, did prevent saprophytic fungi from invading blighted portions of the needles. It is concluded from this investigation that SNB is not a disease of fungal origin.

OZONE DAMAGE AND SEMIMATURE-TISSUE NEEDLE BLIGHT OF EASTERN WHITE PINE

1967 ◽  
Vol 45 (11) ◽  
pp. 2047-2061 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Urban Areas ◽  
Average Concentration ◽  
Atmospheric Ozone ◽  
White Pine ◽  
Eastern White Pine ◽  
Naturally Occurring ◽  
Apparent Relationship ◽  
Coulometric Method ◽  
High Concentrations ◽  
Needle Blight

Investigations were conducted in forests remote from large urban areas to determine whether there was any cause and effect relationship between naturally occurring atmospheric ozone (O3) and semimature-tissue needle blight (SNB) of eastern white pine (Pinus strobus). The daily average concentration of atmospheric ozone, relative to cracking by rubber test strips, was determined for three seasons and no apparent relationship was found between excessive rubber cracking and the occurrence of outbreaks of SNB on susceptible white pines. The repeated application of vitamin C, a reducing agent, to newly developing needles of susceptible white pines, did not prevent the appearance of the symptoms of SNB or retard subsequent symptom development. In fumigation experiments with artificially produced ozone, concentrations of over 0.60 p.p.m., as measured by the manual potassium iodide method, or 0.40 p.p.m. by the coulometric method, were required to produce severe markings on the new needles of the white pine under study. Foliage on material derived from trees non-susceptible to SNB was more responsive to these high concentrations of ozone and exhibited more uniform damage than foliage derived from trees susceptible to SNB. The macroscopic and microscopic symptoms of damage caused by excess ozone were dissimilar from the typical symptoms of SNB. The results of these investigations indicate that naturally occurring atmospheric ozone in stands of eastern white pine is not an incitant of SNB.

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.

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