Seasonal periodicity in the discharge of Pucciniastrum goeppertianum basidiospores

1977 ◽  
Vol 55 (7) ◽  
pp. 745-751 ◽  
Author(s):  
G. A. Van Sickle

Discharge of Pucciniastrum goeppertianum (Kühn) Kleb. basidiospores from witches' brooms on lowbush blueberry (Vaccinium angustifolium Ait. and V. myrtilloides Michx.) in central New Brunswick occurred at irregular intervals from mid-May to late June in 1973 and 1974, but more than 75% of the total catch occurred in a 1-week period each year. Annual timings were related to spring weather variation so that discharge peaks each year coincided with shoot elongation of the aecial host, balsam fir (Abies balsamea (L.) Mill.). Measurable rainfall preceded all major discharge peaks; relative humidity and temperature were factors only as they affected the rate of drying of the hypertrophied twigs. Basidiospore concentration at 15, 90, and 150 cm above the ground level brooms decreased at a ratio of 7:2:1.

1996 ◽  
Vol 128 (5) ◽  
pp. 957-958 ◽  
Author(s):  
Troy L. Whidden

Lowbush blueberry (Vaccinium angustifolium Ait., V. myrtilloides Michx.) growers often use colonies of the European honey bee (Apis mellifera L.) to supplement native bee populations for pollination. Native bee fauna is thought to be insufficient in number and too unpredictable, in terms of numbers, from year to year to be relied on for adequate crop pollination (Kevan and LaBerge 1978; Mackenzie and Winston 1984; Mohr and Kevan 1987; Kevan 1988; Eck 1988).


2010 ◽  
Vol 142 (5) ◽  
pp. 466-472
Author(s):  
Bertrand Guillet ◽  
Andrew Morrison ◽  
Drew Carleton ◽  
Don Ostaff ◽  
Dan Quiring

AbstractWe collected midcrown branches of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), at six different sites located in five different plant-hardiness zones, along a north–south transect in New Brunswick, Canada, to evaluate the effect of plant-hardiness zone, crown class (overstory versus understory), and shoot length during the previous 10 years on the annual incidence of gouting by the balsam woolly adelgid, Adelges piceae (Ratzeburg) (Homoptera: Adelgidae). Site, crown class, and their interaction, along with the square of shoot length, explained 78% of the variation in gouting. Variations in gouting attributed to plant-hardiness zone were probably primarily due to variation in mean January temperature: at each site, the mean January temperature was positively and closely related to the mean level of gouting. The level of gouting was consistently higher on trees in the understory than on those in the overstory. Shoot length was parabolically related to the proportion of shoots with gout. The parabolic relationship between shoot size and the level of gouting is similar to that previously reported for galling adelgids, and suggests that gouting by A. piceae may be greatest on trees with an intermediate growth rate.


1989 ◽  
Vol 67 (12) ◽  
pp. 3513-3516 ◽  
Author(s):  
John A. Johnson ◽  
Norman J. Whitney

Endophytic fungi were isolated from the interiors of surface-sterilized needles of balsam fir (Abies balsamea) and red spruce (Picea rubens) in New Brunswick, Canada. Four different fungi were isolated frequently. One species, designated X-W, was isolated exlusively from the petiole segment of red spruce needles. There was no difference in the variety of species isolated from fir needles from two sites, but a difference in frequency of species did exist. Micrographs of the interior of balsam fir needles showed hyphae occupying intercellular spaces and adhering to the outer walls of parenchyma cells. No penetration of cells by either fungus was observed.


2015 ◽  
Vol 45 (6) ◽  
pp. 659-666 ◽  
Author(s):  
Edward A. Wilson ◽  
David A. MacLean

Forest management regimes increasingly focus on the emulation of natural disturbance events, e.g., fire or insect outbreaks, to help increase ecosystem sustainability. We determined the residual stand response to a variable retention harvest inspired by spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks in New Brunswick, Canada. Our objectives were to analyze the differences between surviving residual trees and those that succumbed to windthrow and to quantify growth release. The treatment was based on harvesting the estimated spruce budworm outbreak mortality, i.e., 90% of mature balsam fir (Abies balsamea (L.) Mill., 60% of mature spruce (Picea spp.), and no hardwoods. Windthrow increased with the proportion of trees harvested and averaged 52% over 7–9 years in these stands with high balsam fir – spruce content. One-third of 42 harvested plots sustained >30% windthrow, whereas 73% of 11 similar unharvested plots had <10% windthrow. Balsam fir had higher windthrow than spruce at 53% and 41%, respectively. Windthrown balsam fir trees had significantly larger diameters at breast height (DBH, 1.3 m), larger heights, and smaller crown ratios than surviving residual trees. Substantial growth release occurred, with DBH increment of residual trees 48%–64% greater than trees in unharvested plots. Balsam fir and intolerant hardwoods exhibited the largest growth response. We suggest that future spruce budworm inspired harvests in stands with high balsam fir – spruce content use two or three entries about 5 years apart to reduce windthrow.


2006 ◽  
Vol 82 (5) ◽  
pp. 700-711 ◽  
Author(s):  
M. Penner ◽  
D E Swift ◽  
R. Gagnon ◽  
J. Brissette

A stand management density diagram (SDMD) is presented for balsam fir (Abies balsamea (L.) Mill.) forests in New Brunswick. The SDMD incorporates a maximum size density line, as well as quadratic mean diameter and top height isolines. Several mortality functions are evaluated. The resultant SDMD should be a useful tool for projecting early stand development and determining the timing and intensity of thinnings. Key words: Acadian Forest Region, mortality curves


2005 ◽  
Vol 35 (10) ◽  
pp. 2479-2490 ◽  
Author(s):  
Sarah Lesley Taylor ◽  
David A MacLean

Data from 585 balsam fir (Abies balsamea (L.) Mill.) and spruce (Picea spp.) permanent sample plots (PSPs) >50 years old in New Brunswick, Canada, measured between 1987 and 1998, were used to quantify the timing, magnitude, and causes of decline in stand growth, measured as negative net volume increment. Plots were subdivided into classes based on species group, ecoregion, and volume-development pattern (decreasing, fluctuating, stable, or increasing volume with time). Decline began at an earlier age in balsam fir – spruce (BFSP) PSPs (~70 years old) than in spruce – balsam fir (SPBF) PSPs (~120 years). One-third of plots (29%) fell into the decreasing volume-development category. Variation in the proportion of decreasing plots occurred among ecoregions (range 0%–60%) and, to a lesser extent, among species groups (26%–33%). Decreasing BFSP plots exhibited double the rate of volume loss of their SPBF counterparts (–7.4 and –3.9 m3·ha–1·year–1, respectively). Decline was caused by an increased rate of mortality, which was highest in the decreasing volume-development classes (7.5 m3·ha–1·year–1) and lowest in the increasing volume-development classes (1.4 m3·ha–1·year–1). Growth of surviving trees remained relatively stable (2.5–4.2 m3·ha–1·year–1) among volume-development classes. Blowdown was the biggest cause of tree mortality, accounting for approximately 50% of dead trees in BFSP and SPBF plots. The rate of mortality was influenced by ecoregion, species, and the combined effect of previous insect-outbreak and wind disturbances.


1951 ◽  
Vol 83 (7) ◽  
pp. 181-183 ◽  
Author(s):  
F. E. Webb ◽  
R. S. Forbes

In 1945 injury to shoots of balsam fir, Abies balsamea (L.) Mill., by sawfly larvae was very common in York and Madawaska counties, New Brunswick. Since then, similar injury has been noticed throughout most of New Brunswick, eastern Nova Scotia, the upper peninsula of Michigan and northern Wisconsin.New Brunswick specimens were identified by Dr. O. Peck of the Systematic Unit, Division of Entomology, as presumably Pleroneura borealis Felt, the specimens running to this species in Ross' Key (2); however, as stated by Ross (3), the recognition of species in the genus is not at present based upon fundamental characters. P. borealis was originally described in 1917 by Felt (1) from three specimens collected at Lake Clear, N.Y., in 1907. Except for the taxonomic revision by Ross (2), no other reference to this species was found in the literature.


1973 ◽  
Vol 51 (6) ◽  
pp. 1161-1168 ◽  
Author(s):  
K. Loach ◽  
C. H. A. Little

Rates of net photosynthesis and dark respiration of 1-year-old and currently developing foliage were measured in the uppermost (i.e. 1-year-old) whorl of branches of 6-year-old balsam fir trees (Abies balsamea (L.) Mill.) during the period of extension growth of the current shoot. The rates were integrated to estimate net dry matter production by the two ages of foliage, and compared with dry matter requirements for growth of the new shoot (estimated from a regression equation of length over dry weight), and with cambial growth in the 1-year-old shoot (estimated from periodic harvests). The surplus of production over use in these two sinks was stored temporarily in the 1-year-old foliage or exported from the branch, the latter predominating. Two periods in which a large proportion of the photosynthetic production was exported (corresponding roughly to the months of May and July) were separated by a period when export was relatively low. At this intermediate time, current photosynthetic production was minimal and local growth demands were at their highest. Photosynthates stored in the 1-year-old foliage before budbreak supplemented current photosynthesis and permitted export to continue, except for a few days at the end of June. The contribution from stores in the old foliage, however, never exceeded one-third of current photosynthetic production. When extension growth terminated, a second transient storage peak occurred in the 1-year-old foliage for about 2 weeks. These observations explain the commonly observed reduction in root growth during current shoot extension, and corroborate results from studies made by other investigators using radioactive tracers.


2013 ◽  
Vol 145 (4) ◽  
pp. 430-434
Author(s):  
Rob C. Johns ◽  
J. Fidgen ◽  
Don P. Ostaff

AbstractLaboratory experiments using field-collected females were carried out to determine the oviposition preference of the balsam fir sawfly, Neodiprion abietis (Harris) (Hymenoptera: Diprionidae) in New Brunswick, Canada. Unmated adult females given no choice among host–plant foliage laid ∼98% of available eggs on balsam fir (Abies balsamea (Linnaeus) Miller; Pinaceae), but only 8% and 10%, respectively, on white spruce (Picea glauca (Moench) Voss; Pinaceae) and black spruce (Picea mariana (Miller) Britton, Sterns, and Poggenburg). Given a choice among shoots from all three hosts in the same chamber, unmated females laid all but one egg in balsam fir. Host plant had no effect on female longevity, although there were nearly four- to eightfold more empty egg slits on balsam fir needles, owing presumably to the greater activity of females on this preferred host foliage.


1986 ◽  
Vol 118 (1) ◽  
pp. 69-77 ◽  
Author(s):  
D.C. Eidt ◽  
V.N. Mallet

AbstractFenitrothion accumulates in foliage tissue of balsam fir, Abies balsamea (L.) Mill., in the forest, but only until about 1.5 μg/g is reached. The balsam fir sawfly, Neodiprion abietis (Harris), which belongs to the family of forest insects known to be most sensitive to fenitrothion, has become rare but persists in New Brunswick in spite of the use of fenitrothion for control of spruce bud worm, Choristoneura fumerifana (Clemens).


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