Role of Armillaria calvescens and Glycobius speciosus in a sugar maple decline

1992 ◽  
Vol 22 (4) ◽  
pp. 549-552 ◽  
Author(s):  
Eric Bauce ◽  
Douglas C. Allen

Sugar maple, Acersaccharum Marsh., decline may be reversible during early stages before secondary insects and fungi invade stressed trees. Treatment with boric acid reduced the regenerative capacity of Armillariacalvescens Bérubé & Dessureault rhizomorphs and the percent infection of trembling aspen, Populustremuloides Michx., stakes used as a bioassay. One year after treatment, crown condition and cambial electrical resistance of trees initially in early stages of crown dieback improved compared with controls. The crown condition of sugar maples previously attacked by the sugar maple borer, Glycobiusspeciosus (Say), did not improve during 5 years of observation, whereas 18% of uninfested trees in similar initial crown condition did improve. Sugar maple borer was more abundant in declining trees [Formula: see text] than is typical of nondeclining infested trees [Formula: see text]. Declining trees had more sugar maple borer damage than apparently healthy trees (no evidence of crown dieback). The borer and the fungus are important contributing agents that prevent recovery of many declining sugar maples.

1992 ◽  
Vol 22 (2) ◽  
pp. 264-266 ◽  
Author(s):  
Eric Bauce ◽  
Douglas C. Allen

An 85-year-old even-aged northern hardwood stand was studied to elucidate relations between the crown condition of declining sugar maples, Acersaccharum Marsh., and the condition of maple fine roots. Declining sugar maples had lower fine-root biomass and fewer rootlet tips than apparently healthy trees. However, rootlet mortality did not differ significantly between crown dieback classes. Damage to fine roots caused by Ctenophora sp. was significantly greater on trees in advanced stages of decline.


1992 ◽  
Vol 22 (11) ◽  
pp. 1776-1784 ◽  
Author(s):  
Douglas C. Allen ◽  
Charles J. Barnett ◽  
Imants Millers ◽  
Denis Lachance

Change in the health of sugar maple (Acersaccharum Marsh.) and associated northern hardwoods was evaluated for 3 years (1988–1990) in seven states and four provinces. Generally, levels of crown dieback and crown transparency (a measure of foliage density) in 165 stands decreased during this period. In 1990, less than 7% of all dominant–codominant sugar maples (n = 7317) exhibited crown dieback ≥ 20%. Significantly (p = 0.05) fewer of these maples were classified as having high crown transparency (≥ 30%) in 1990 compared with 1988. Crowns of maples that received moderate (31–60%) or heavy (> 60%) pear thrips (Taeniothripsinconsequens (Uzel)) damage for 1 year recovered the following year. Crowns of maples exposed to severe drought in 1988 (Wisconsin) continued to show the effects (high transparency) of this stress in 1990. A majority (69–71%) of the dominant–codominant sugar maples with high (≥ 20%) crown dieback had bole and (or) root damage. Of those maples with crown dieback ≥ 50%, 86% had bole and (or) root damage. The condition of sugar maple in operating sugar bushes and undisturbed stands was similar. The condition of sugar maple crowns was similar in locations presumably exposed to low, medium, and high levels of sulfate deposition.


1998 ◽  
Vol 15 (3) ◽  
pp. 141-145
Author(s):  
Anthony A. Hopkin ◽  
Gordon M. Howse

Abstract Surveys of sugar maple trees, conducted in Ontario between 1987 and 1995, showed a general improvement in crown condition after 1990. Plots on the shallow soils of the Precambrian shield in central Ontario showed the highest levels of crown dieback in all years. This area was also defoliated at moderate-to-severe levels in 1988. Dieback levels on undefoliated plots were high in 1987-1988, but plots improved after 1988. Defoliated plots showed no improvement, and dieback remained high through 1995. Crown dieback was lower in forest and urban situations than at roadside plots. Roadside plots showed high levels of dieback and should be considered poor indicators of forest condition. Pest damage was recorded on all plot types. Sugar maple in both urban and roadside locations had a higher incidence of stem defects, stem canker, and stem insect damage than trees in forest plots. Root rots were most prevalent at roadside locations. Stem cankers, stem defects, and root rot were most common in the northern forest plots. North. J. Appl. For. 15(3): 141-145.


1977 ◽  
Vol 7 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Dennis Newbanks ◽  
Terry A. Tattar

Electrical resistance (ER) measurements of the xylem–cambium area were affected by time of year, air temperature, tree diameter, species, bark blemishes, callus tissue, decay, and measurement techniques. Our results indicate that in urban sugar maples there was no statistically significant correlation between ER and tree response to physiologic stress, as measured by visual crown classification (based on the severity of decline symptoms) and by increment core data. Trees in a non-urban, campus setting showed a significant correlation between electrical resistance and visual crown symptoms (r = 0.61). Trees with intermediate crown-condition ratings had the highest average ER, and on the basis of ER, individual trees could not be placed into stress-response categories because of large variations in ER within each crown-condition class. No significant correlation was found between ER and applied physiologic stresses in nursery-grown sugar maples.


1978 ◽  
Vol 8 (4) ◽  
pp. 375-379 ◽  
Author(s):  
Roberta A. Spitko ◽  
Terry A. Tattar ◽  
Richard A. Rohde

Twelve sugar maples (Acersaccharum Marsh.) on the campus of the University of Massachusetts were selected for the study in spring 1977. Trees chosen ranged from healthy to severely declined and were assigned to crown-condition classes of increasing severity from I to IV. Whole root samples from each tree were cleared in 10% KOH and stained in trypan blue to assess the degree of vesicular–arbuscular infection. Five sections of secondary feeder roots from each tree were selected at random and examined under a microscope. The number of infected cortical cells per centimetre of roots was counted to give an estimate of percent mycorrhizal infection for each tree. An inverse relationship was found between the degree of decline shown by the crown and the amount of mycorrhizal infection in the roots. Trees of class I had young infections showing extensive arbuscule development and few vesicles. In classes II to IV there was a decrease in the number of cortical cells infected by the fungus and an increase in vesicle formation, at times to the point where cortical cells were disrupted by their presence. In class IV, arbuscules that were present had undergone digestion of the fine branches so that only the collars were in evidence. Soil pH and nutritional status were determined but no relationship was found between these factors and the health of the fungal symbiont in the roots.


1995 ◽  
Vol 25 (3) ◽  
pp. 386-397 ◽  
Author(s):  
Timothy R. Wilmot ◽  
David S. Ellsworth ◽  
Melvin T. Tyree

We compared growth with soil and foliar elemental composition in seven stands of sugar maple (Acersaccharum Marsh.) in northern Vermont characterized by high or low incidence of crown dieback over the period 1989–1992. In stands with low-quality crown conditions, such as elevated crown dieback, long-term basal area growth rates were approximately half of those in stands with higher crown quality. Average annual basal area growth was 17.5 cm2 for dominant trees in these stands during the period 1953–1992 compared with 32.3 cm2 for trees in higher quality stands. The occurrence of elevated crown dieback was apparently unrelated to stand characteristics such as stand age, basal area, stem density, elevation, or aspect among the stands sampled. Stands with elevated crown dieback were found on soils characterized by low pH ( <4.0), low base cation pools (particularly Ca and Mg), and higher Al in soil surface horizons than higher quality stands. Over 4 years, sugar maple stands with elevated crown dieback exhibited significantly lower (P < 0.01) foliar Ca concentrations and somewhat lower foliar N and Mg than higher quality stands, while soil and foliar K were similar in both dieback classes. Among survey plots sampled in 1989, soil pH and Ca were strongly correlated with foliar Ca and K (P < 0.001). Soil pH, soil Ca, and foliar Ca were also strongly correlated with the level of crown dieback among plots and stands (P < 0.0001). Our results indicate that podzolic soils in northern Vermont may present marginal conditions for sugar maple growth in terms of soil pH and soil Ca availability, but that P and K pools appear to be sufficient for growth. While a lack of historical data prevents identification of long-term trends in nutrient availability in these soils, factors promoting losses of base cations from acidic, base-cation-poor Podzols may also exacerbate foliar nutrient deficiencies and thus affect the crown condition of sugarbushes in northern Vermont.


1992 ◽  
Vol 124 (6) ◽  
pp. 1129-1138 ◽  
Author(s):  
E. Carey ◽  
R.G. Van Driesche ◽  
J.S. Elkinton ◽  
T.S. Bellows ◽  
C. Burnham

AbstractWidespread defoliation of sugar maple stands due to pear thrips, Taeniothrips inconsequens (Uzel), feeding occurred in Massachusetts in 1987 and 1988. To assess the role of tree health as a possible cause of these outbreaks, an experiment was conducted in sugar maple stands in Massachusetts in 1990. Sleeve cages were placed on mature sugar maples and stocked with adult female pear thrips to determine the relation between root starch reserves (an index of tree health) and thrips fecundity. The experiment was run at four sites, assessing both root starch levels and thrips fecundity on individual trees. Each stand showed a range from high to low starch values and trees at each end of the root starch index spectrum were selected for use in the experiment at each site. Analysis of data showed no differences between sites, apart from those linked to starch levels, and found thrips fecundity to be positively correlated with higher starch reserves. The results of this experiment do not support the original hypothesis that declining tree health was a causal factor in pear thrips outbreaks on sugar maple in Massachusetts.


WCET Journal ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 9-18
Author(s):  
Wai Sze Ho ◽  
Wai Kuen Lee ◽  
Ka Kay Chan ◽  
Choi Ching Fong

Objectives The aim of this study was to retrospectively review the effectiveness of negative pressure wound therapy (NPWT) in sternal wound healing with the use of the validated Bates-Jensen Wound Assessment Tool (BWAT), and explore the role of NPWT over sternal wounds and future treatment pathways. Methods Data was gathered from patients' medical records and the institution's database clinical management system. Seventeen subjects, who had undergone cardiothoracic surgeries and subsequently consulted the wound care team in one year were reviewed. Fourteen of them were included in the analysis. Healing improvement of each sternal wound under continuous NPWT and continuous conventional dressings was studied. In total, 23 continuous NPWT and 13 conventional dressing episodes were analysed with the BWAT. Results Among conventional dressing episodes, sternal wound improvement was 2.5–3% over 10 days to 3.5 weeks, whereas 4–5% sternal healing was achieved in 5 days to 2 weeks with sternal wire presence. Better healing at 11% in 1 week by conventional dressing was attained after sternal wire removal. In NPWT episodes, 8–29%, 13–24%, and 15–46% of healing was observed in 2 weeks, 3.5 to 5 weeks and 6 to 7 weeks, respectively. Only 39% wound healing was acquired at the 13th week of NPWT in one subject. With sternal wire present, 6%–29% wound healing progress was achieved by NPWT in 1–4 weeks, and 16–23% wound improvement in 2 to 4.5 weeks by NWPT after further surgical debridement. After sternal wire removal, 6–34% sternal wound healing occurred by continuous NPWT for 1–2 weeks, and maximum healing at 46% after 2.5 weeks of NPWT were observed. Conclusions Better wound healing was achieved in the NPWT group in comparison to conventional dressings alone. However, suboptimal sternal wound healing by NPWT alone was observed. Removal of sternal wire may improve the effectiveness of NPWT. Successful tertiary closure after NPWT among subjects supports the important bridging role of NPWT in sternal wound healing. Factors causing stagnant sternal wound healing by NPWT alone are discussed.


1968 ◽  
Vol 58 (3) ◽  
pp. 364-376 ◽  
Author(s):  
S. Pesonen ◽  
M. Ikonen ◽  
B-J. Procopé ◽  
A. Saure

ABSTRACT The ovaries of ten patients, at least one year after the post-menopause, were incubated with two Δ5-C19-steroids and also studied histochemically. All these patients had post-menopausal uterine bleeding and increased oestrogen excretion of the urine. The urinary estimations of gonadotrophins, 17-KS, 17-OHCS and pregnanediol were carried out on all patients. Vaginal smears were read according to Papanicolaou, and the endometrium and ovaries were studied histologically. The incubation experiments indicate the presence of Δ5-3β-hydroxysteroid-dehydrogenase. When androst-5-ene-3β,17β-diol was used as precursor the formation of testosterone occurred without any concomitant production of DHA and/or androstenedione. This seems to indicate the possible role of the Δ5-pathway in the formation of testosterone by post-menopausal ovarian tissue. The histochemical reactions indicated a reducing activity on NADH, lactate and glucose-6-phosphate, in certain corpora albicantia, atretic follicles and in diffuse thecoma regions in the cortical layer of the ovary. Steroid-3β-ol-dehydrogenase and β-hydroxybutyrate-dehydrogenase were found only at the edges of certain corpora albicantia, in some individual stroma cell groups and in some atretic follicles. Our studies, both biochemical and histochemical, suggest that the observed increase in the urinary oestrogens of the patients studied might in part at least, be of ovarian origin. This opinion is also supported by the postoperative oestrogen values.


2012 ◽  
Vol 2 (2) ◽  
pp. 345-350
Author(s):  
Dr. Girish.L Dandagi ◽  
◽  
Venkat kalyana kumar. P ◽  
Dr. Dr.Isaac Mathew ◽  
Dr. Dr.G S Gaude Dr. Dr.G S Gaude

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