Effective use of ethylene-releasing agents to prevent spread of eastern dwarf mistletoe on black spruce

1985 ◽  
Vol 15 (5) ◽  
pp. 872-876 ◽  
Author(s):  
William H. Livingston ◽  
Robert A. Blanchette ◽  
Mark L. Brenner ◽  
Kathryn J. Zuzek

Ethylene-releasing agents (ethephon, ethanedial dioxime, etacelasil, 2-chloroethyl-methylbis(phenylmethoxy)-silane, and 1-aminocyclopropane-1-carboxylic acid) applied to dwarf mistletoe (Arceuthobiumpusillum Pk.) infections on black spruce (Piceamariana (Mill.) B.S.P.) in four separate tests (August 1982, 1983, and 1984 and May 1983) promoted premature abscission of mistletoe shoots. Concentrations of the chemicals ranged from 12 to 5000 μg/g. Surfactants (Ortho X-77 and PGFI-100) were evaluated for increasing the effectiveness of the ethylene-releasing agents. The treatment combination that consistently resulted in 74–100% abscission of dwarf mistletoe shoots was August applications of 2500 μg/g ethephon plus either surfactant. Treatments did not significantly affect growth of black spruce or subsequent growth of dwarf mistletoe shoots. Abscission of dwarf mistletoe shoots prevents spread of the disease in black spruce for 2 years and for at least 4 years in some western conifers.

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.


1973 ◽  
Vol 3 (2) ◽  
pp. 312-315 ◽  
Author(s):  
F. H. Tainter ◽  
D. W. French

Upward movement of acid fuchsin dye solution in dwarf mistletoe-infected black spruce trees generally occurred in a helical pattern. In seven of ten trees the dye ascended in a counterclockwise direction around the axis of the tree. All trees showed wide variation in direction of ascent, in some cases the dye column reversed direction of ascent partially up the bole. In some instances the witches' brooms apparently attracted the dye.


1983 ◽  
Author(s):  
Michael E. Ostry ◽  
Thomas H. Nicholls ◽  
D.W. French
Keyword(s):  

2012 ◽  
Vol 29 (3) ◽  
pp. 109-112 ◽  
Author(s):  
Fred Baker ◽  
Mark Hansen ◽  
John D. Shaw ◽  
Manfred Mielke ◽  
Dixon Shelstad

1979 ◽  
Vol 9 (4) ◽  
pp. 544-545
Author(s):  
Fred A. Baker Jr. ◽  
D. W. French

Perennial aerial shoots of Arceuthobiumpusillum Peck with flabellate branching were found in Minnesota. Removal of aerial shoots, presumably by birds, from several dwarf mistletoe plants was also noted. Although rare in other host – dwarf mistletoe combinations, secondary infections are commonly found on black spruce (Piceamariana (Mill.) BSP).


1971 ◽  
Vol 47 (1) ◽  
pp. 33-35 ◽  
Author(s):  
William F. Johnston

Slash burning tests showed that summer broadcast burning is superior to both winter progressive burning and no disposal for reproducing black spruce on clearcut areas in north-central Minnesota. Broadcast burning is superior because: 1 it exposes moist sphagnum moss and consumes dry mosses, and thus produces favorable seedbeds over the entire clearcut area; 2 it kills all residual conifers and eradicates dwarf mistletoe; and 3 assuming slash disposal is prescribed, it is much cheaper than progressive burning.


1997 ◽  
Vol 51 (11) ◽  
pp. 1648-1655 ◽  
Author(s):  
Umesh P. Agarwal ◽  
Sally A. Ralph

Good-quality Raman spectra of most wood species can now be obtained by using near-infrared Fourier transform Raman spectroscopy. To make effective use of such spectroscopic information, one needs to interpret the data in terms of contributions from various wood components and, for each component polymer, in terms of vibrational modes of its substructural units/groups. In the present work, Raman spectral features of black spruce (Picea mariana) wood were associated with lignin and/or carbohydrate polymers. Lignin's spectral contributions were recognized in several ways. In addition to spectra of milled-wood and enzyme lignins, a spectrum of native lignin was obtained by subtracting the spectrum of acid chlorite delignified black spruce from the spectrum of an untreated wood sample. A comparison of lignin spectra indicated that the Raman features of the three lignins are very similar. Raman contributions of carbohydrate polymers, namely, those of cellulose and hemicellulose, were identified by using authentic and/or isolated samples and, in the case of cellulose, by using previously published spectra. Such an analysis showed that the hemicellulose present in black spruce did not give rise to any new, unique features that were not already present due to cellulose. Therefore, it was concluded that the hemicellulose contribution is broad and is hidden under the Raman contribution of cellulose. Also, peak positions of lignin contributions did not overlap with those of cellulose, and there were spectral regions where either lignin or cellulose contributed.


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