Phyllosticta multicorniculata on Abies spp. in the Northeastern U.S.

Several needle blight fungi affect natural regeneration and Christmas tree plantations of Abies spp. in northeastern North America. Of these, Phyllosticta multicorniculata Bissett & Palm has been reported from A. balsamea (L.) Mill. in Ontario and Prince Edward Island, and from A. concolor (Gordon & Glend.) Lindl. ex Hildebr. in Wisconsin (1). In Quebec, P. multicorniculata was reported as an endophyte on symptomless needles of A. balsamea (2). In 1994, we collected this fungus in Grafton County, NH, defoliating lower branches of A. balsamea Christmas trees. In July and August 1996, we examined infected A. concolor Christmas trees in Lamoille County, VT. In July, approximately 50% of the 1996 needle complement on the lower 1 m of the crowns was infected and by August the incidence of infection on these branches increased to 75 to 100%. Less severe blighting occurred up to 1.5 m. Dead needles of the 1995 complement bore abundant, mostly empty, pycnidia of P. multicorniculata. The dead and dying distal ends of the 1996 needle complement bore abundant pycnidia of P. multicorniculata in various stages of maturation. This is the first report of this pathogen on Abies spp. in the northeastern U.S. The conidia from actively-sporulating pycnidia bore more numerous and longer appendages (1 to 16, average 7, up to 38 µm long) than the dried herbarium specimens of various ages used in the species description (1 to 5, up to 7 µm long) (1), or similarly reported from culture (2). References: (1) J. Bissett and M. E. Palm. Can. J. Bot. 67:3378, 1989. (2) L. Petrini et al. Sydowia 43:148, 1991.

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Incidence of Monochamus (Coleoptera: Cerambycidae) species in Nova Scotia, Canada Christmas tree plantations and comparison of panel traps and lures from North America and Europe

The Canadian Entomologist ◽

10.4039/tce.2016.55 ◽

2016 ◽

Vol 149 (2) ◽

pp. 191-203 ◽

Cited By ~ 3

Author(s):

S.E. Blatt ◽

C. Bishop ◽

J. Sweeney

Keyword(s):

Nova Scotia ◽

North America ◽

North American ◽

Bursaphelenchus Xylophilus ◽

Tree Plantations ◽

Christmas Tree ◽

Pinewood Nematode ◽

The European Union ◽

Christmas Trees ◽

Trap Catches

AbstractChristmas trees from Nova Scotia, Canada are banned from import into the European Union (EU) because they may be infected with the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae). Monochamus Dejean (Coleoptera: Cerambycidae) species known to vector pinewood nematode are present in Nova Scotia but their abundance in Christmas tree plantations and surrounding stands has not been assessed. We conducted trapping surveys and experiments in 2014 and 2015 to determine the species of Monochamus and their relative abundance in Nova Scotia Christmas tree plantations and the surrounding forests. We also compared commercially available traps and lures from Europe (cross-vane traps, Galloprotect lure=monochamol+ipsenol+α-pinene+2-methyl-3-buten-2-ol) and North America (intercept panel traps, North American lure=monochamol+ipsenol+α-pinene+ethanol) for their efficacy at catching Monochamus species in a 2×2 factorial experiment. We captured three Monochamus species (M. scutellatus (Say), M. notatus (Drury), and M. marmorator Kirby) in Nova Scotia Christmas tree plantations. Mean trap catches were greater within the plantations than in the surrounding forests. North American panel traps coated with Fluon® and baited with the European lure caught the most M. notatus and M. scutellatus and would be most suitable for survey and monitoring.

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Bionomics of the pine needle scale (Hemiptera: Diaspididae), an emerging pest in Christmas tree (Pinaceae) plantations in southern Québec, Canada

The Canadian Entomologist ◽

10.4039/tce.2018.41 ◽

2018 ◽

Vol 150 (5) ◽

pp. 632-636 ◽

Cited By ~ 1

Author(s):

Jean-Frdéric Guay ◽

Amy Bernier-Desmarais ◽

Jean-François Doherty ◽

Conrad Cloutier

Keyword(s):

Life Cycle ◽

Scale Insects ◽

Tree Plantations ◽

Christmas Tree ◽

Pine Needle ◽

Abies Fraseri ◽

Fraser Fir ◽

Christmas Trees ◽

Significant Damage ◽

The Status

AbstractThe pine needle scale, Chionaspis pinifoliae (Fitch) (Hemiptera: Diaspididae), has the status of an emerging pest in Christmas tree (Pinaceae) plantations in Québec, Canada. The scale is not known to cause any significant damage yet and is not generally monitored by growers. However, it can be an obstacle for exportation to Christmas tree markets where scale insects are strictly regulated. In this study, we describe its life cycle in Christmas tree plantations in southern Québec. We confirm the presence of both parthenogenetic and sexual forms of the scale on Fraser fir Abies fraseri (Pursh) Poiret (Pinaceae) grown as Christmas trees, and of parasitoid and Coccinellidae (Coleoptera) specialists that could contribute to its control.

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Temperature-manipulated dynamics and phenology ofMindarus abietinus(Hemiptera: Aphididae) in commercial Christmas tree plantations in Québec, Canada

The Canadian Entomologist ◽

10.4039/tce.2017.41 ◽

2017 ◽

Vol 149 (6) ◽

pp. 801-812 ◽

Cited By ~ 5

Author(s):

Jean-François Doherty ◽

Jean-Frédéric Guay ◽

Conrad Cloutier

Keyword(s):

Growth Rates ◽

Local Population ◽

Colony Growth ◽

Early Summer ◽

Tree Plantations ◽

Christmas Tree ◽

Christmas Trees ◽

Size Growth ◽

Major Pest ◽

Potential Damage

AbstractThe balsam twig aphidMindarus abietinusKoch (Hemiptera: Aphididae) is a major pest of economic importance for the Christmas tree industry. Global warming during the 21st century could potentially increase local population densities and reinforce the pest status of this aphid in commercial fir (AbiesMiller; Pinaceae) plantations in Québec, Canada. During this study, we tested the effects of a warmer environment on colony growth rates ofM. abietinusand aphid morph composition during the second generation of its cycle, which is key to colony size growth and potential damage to Christmas trees. We monitoredM. abietinuspopulations on two host fir species and one host fir variety, in order to understand the early season dynamics of this aphid and its host tree. It was possible to distinguish the two overlapping generations of winged aphids leaving colonies, which led to observing a much higher proportion of wingless daughters, produced by the stem mother, than what had previously been reported. Colony growth rates were significantly higher in a warmer environment than in the nearby plantation, suggesting that warmer temperatures in late spring and early summer may provide the suitable conditions required forM. abietinuscolonies of greater density.

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ACHILLEA MILLEFOLIUM COMPLEX IN CANADA AND PORTIONS OF THE UNITED STATES

Canadian Journal of Botany ◽

10.1139/b59-007 ◽

1959 ◽

Vol 37 (1) ◽

pp. 73-79 ◽

Cited By ~ 8

Author(s):

Gerald A. Mulligan ◽

I. John Bassett

Keyword(s):

North America ◽

Prince Edward Island ◽

Native Species ◽

Pollen Grains ◽

The United States ◽

Achillea Millefolium ◽

Herbarium Specimens ◽

Male Sterile ◽

Eastern Canada ◽

The Pacific

The chromosome numbers of plants of the Achillea millefolium complex from 27 locations in North America are reported. The levels of polyploidy found are correlated with diameters of the pollen grains. Measurements of pollen grains from more than 300 herbarium specimens are used as an indication of the occurrence of tetraploid and hexaploid species of Achillea in Canada. The results of some crossing experiments are also reported. It is concluded that the common Achillea of North America is tetraploid and is the native A. lanulosa Nutt. It extends from the Pacific to the Atlantic coasts, as far south as California in the west and Pennsylvania in the east, and to northern Canada and Alaska. Another native species, hexaploid Achillea borealis Bong., extends along the Pacific coast from southern California to the Aleutian Islands and along the northern shorelines of Alaska and Canada. A Eurasiatic hexaploid, A. millefolium L. s. str., has been sparingly introduced into Newfoundland, Prince Edward Island, Nova Scotia, and perhaps elsewhere along the Atlantic seaboard. In eastern Canada a male-sterile purple-flowered hexaploid also occurs. This hexaploid escapes from cultivation and forms localized patches. It undoubtedly has been selected from the Eurasiatic A. millefolium L. s str.

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Podabrus rugosulus (Coleoptera: Cantharidae), an opportunist predator of Mindarus abietinus (Hemiptera: Aphididae) in Christmas tree plantations

The Canadian Entomologist ◽

10.4039/ent133151-1 ◽

2001 ◽

Vol 133 (1) ◽

pp. 151-154 ◽

Cited By ~ 5

Author(s):

Richard Berthiaume ◽

Christian Hébert ◽

Conrad Cloutier

Keyword(s):

Abies Balsamea ◽

The United States ◽

Balsam Fir ◽

Tree Plantations ◽

Christmas Tree ◽

Eastern Canada ◽

Aesthetic Value ◽

Christmas Trees ◽

Major Pest ◽

The Aesthetic

The balsam twig aphid, Mindarus abietinus Koch, is a major pest of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), grown as Christmas trees in eastern Canada and the United States (Nettleton and Hain 1982; Kleintjes 1997). This aphid has three or four generations from April to July, and overwinters as eggs on fir shoots. Mature fundatrices deposit progeny on new shoots in late May. Infested shoots develop into pseudogalls characterised by stunting and needle distortion, thus reducing the aesthetic value of trees.

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The Christmas Tree: Traditions, Production, and Diseases

Plant Health Progress ◽

10.1094/php-2000-1013-01-rv ◽

2000 ◽

Vol 1 (1) ◽

pp. 15 ◽

Cited By ~ 14

Author(s):

Gary A. Chastagner ◽

D. Michael Benson

Keyword(s):

North America ◽

Root Rot ◽

Stem Canker ◽

Christmas Tree ◽

Phytophthora Root Rot ◽

Current Season ◽

Fraser Fir ◽

Needle Blight

This article takes a historical look at the Christmas tree industry and discuss three diseases limiting growers' ability to meet the demand for noble and Fraser fir in North America: Phytophthora root rot and stem canker, current season needle necrosis (CSNN), and interior needle blight. Accepted for publication 14 September 2000. Published 13 October 2000.

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Spread of Heterobasidion annosum in Christmas Tree Plantations of the United States Pacific Northwest

Phytopathology ◽

10.1094/phyto-97-5-0551 ◽

2007 ◽

Vol 97 (5) ◽

pp. 551-556 ◽

Cited By ~ 2

Author(s):

N. L. Dart ◽

G. A. Chastagner ◽

T. L. Peever

Keyword(s):

Pacific Northwest ◽

Spatial Scales ◽

Secondary Infection ◽

Root Systems ◽

The United States ◽

Heterobasidion Annosum ◽

Tree Plantations ◽

Christmas Tree ◽

Mature Trees ◽

Christmas Trees

The population structure of Heterobasidion annosum in the Pacific Northwest (PNW) Christmas tree plantations was estimated at two spatial scales to assess the relative importance of primary and secondary infection, colonization, and spread of the pathogen. Ninety-three isolates from single trees in 27 discrete mortality pockets and 104 isolates from 12 individual root systems of noble and Fraser fir trees were sampled near Mossyrock, Washington. Isolates were genotyped using somatic compatibility assays and microsatellite markers to determine the spatial scale at which dispersal of single genotypes (genets) was occurring. All isolates sampled from different trees in discrete mortality pockets had distinct genotypes, whereas the root systems of single trees were dominated by one or two genotypes. These results suggest that infection of PNW Christmas trees results from frequent primary infection events of adjacent stumps and localized secondary spread within root systems rather than clonal spread of the pathogen between adjacent trees. We hypothesize that mortality pockets may be due to availability of infection courts and/or variation in inoculum levels during selective harvesting of patches of mature trees.

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A Review of Non-Chemical Weed Control Practices in Christmas Tree Production

Forests ◽

10.3390/f11050554 ◽

2020 ◽

Vol 11 (5) ◽

pp. 554

Author(s):

Debalina Saha ◽

Bert M. Cregg ◽

Manjot Kaur Sidhu

Keyword(s):

Weed Control ◽

Tree Growth ◽

Cover Crops ◽

Biological Agents ◽

Nitrogen Fertilizers ◽

Tree Plantations ◽

Christmas Tree ◽

Weed Species ◽

Christmas Trees ◽

Tree Production

Weeds interfere with Christmas tree growth at any time and at any stage of production. Growers mostly rely on mechanical mowing and applications of herbicides for weed control in their fields. However, herbicides can be phytotoxic to non-target plants, can cause environment-related issues, and their repeated application can even cause herbicide-resistant weeds. The main objective of this manuscript is to provide a review of non-chemical weed control strategies in Christmas tree production and identify areas where current practices could potentially be improved or in which further research is required. Preventing the introduction of weed seeds requires controlling weeds along farm roads, maintaining clean equipment, and eliminating new weeds before they start seeding. Mowing helps to reduce the number of seeds produced by the weeds and can significantly reduce competition with trees. Shropshire sheep are well suited for grazing Christmas tree plantations as they prefer grazing on grasses and weeds rather than on coniferous trees. Weeds can also be controlled around Christmas trees by mulching. Organic mulch can improve soil moisture, maintain soil temperatures, enhance root establishment and transplant survival, and improve plant establishment and overall growth. Incorporating cover crops into Christmas tree plantations may improve tree growth, quality, and soil fertility and can supplement conventional nitrogen fertilizers. However, if cover crops are not properly managed, they can be highly competitive with the trees. Flaming can cause suppression of many annual weed species but is less effective on larger weeds and needs to be applied with caution. Several insects have been used as biological agents to control selective weed species. However, further research is required to focus on several potential biological agents, different types and depths of mulches, on cover crops types and their competition with different species of Christmas trees and their effects on seedling survival and growth.

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