News & Press

Current EAB Research at the University of Minnesota and EAB Management Guidelines Are the Topics of

Mon, 5 Apr 2021 16:36:12 GMT

The Minnesota Department of Agriculture (MDA) will be hosting two research-based webinars on topics related to emerald ash borer (EAB) during the month of April. Both of these webinars may be of interest to a variety of nursery and landscape professionals.

The first webinar to be hosted by the MDA – Emerald Ash Borer Research: Updates from the University of Minnesota – will begin at 11:00 a.m. on Thursday, April 15, 2021, and will highlight research being performed by researchers in the University of Minnesota's Forest Entomology Lab. Presenters will include Dr. Brian Aukema and graduate students Dorah Mwangola and Jake Wittman. Attendees will learn about Dorah's research on the optimization of EAB insecticide treatments and Jake's work on determining the attractive range of a new green prism EAB detection trap baited with sex pheromone and ash volatile lure combination. The webinar will include time for questions and answers and 1.0 Continuing Education Unit (CEU) will be available for ISA Certified Arborists and MNLA Certified Professionals who attend. CLICK HERE TO REGISTER FOR THIS WEBINAR.

The second webinar to be hosted by the MDA – Emerald Ash Borer: Management Guidelines and Insecticide Treatments – will start at 11:00 a.m. on Thursday, April 22, 2021, and will focus on EAB management guidelines and insecticide treatment options. More specifically, Jonathan Osthus, MDA, will discuss EAB management guidelines developed for communities and Jeff Palmer, a certified arborist, will discuss the selection of good treatment candidates, preventative vs. reactive EAB treatments, and the limitations of different EAB treatment options. The webinar will include time for questions and answers and 1.0 Continuing Education Unit (CEU) will be available for ISA Certified Arborists and MNLA Certified Professionals who attend. CLICK HERE TO REGISTER FOR THIS WEBINAR.

With two new counties being added to the Minnesota EAB quarantine already this year, and 27 of Minnesota’s 87 counties now under quarantine for EAB, emerald ash borer continues to spread in Minnesota and keeping up with the latest EAB research and treatment options is important for those who are attempting to manage this highly destructive pest.

To comment on this research update, suggest research topics of interest, or pass along a piece of research-based information that might be of interest to your industry colleagues, please email us at Research@MNLA.biz.

The Challenges of Balancing Public Safety with Plant and Ecosystem Health

Thu, 11 Mar 2021 16:32:23 GMT

The research article covers the basics including the effects of deicing salts on plant and soil health and how to mitigate their effects. The article is a quick and fun read that reminds us of the challenges of balancing public safety with plant and ecosystem health. Given the public safety and liability concerns associated with the accumulation of snow and ice, it is unlikely that the use of deicing salts will be abandoned any time soon. As MNLA professionals who offer snow and ice management services are, however, well aware, there are best management practices that can be used to minimize salt use and the negative effects of deicing salts on the environment. Read full article.

Thanks to Transgenic Research, Blight Resistant American Chestnuts Possible

Tue, 10 Sep 2019 17:15:15 GMT

Prior to 1900, the American chestnut (Castanea dentata), a member of the beech family (Fagaceae), was the dominant tree in eastern forests from Maine and southern Ontario (Canada) to Florida and west to the Ohio River valley accounting for 25% (and in some regions as much as 30-50%) of all the hardwood trees within the range of American chestnut (an estimated population of 4 billion trees). American chestnut was also commonly planted in designed landscapes both in and outside its native range as a shade tree and for its wildlife value. The stately trees grew to heights of 100 feet or more (up to 160 feet) with straight trunks that measured up to eight feet in diameter and was an important species commercially for its edible nuts and attractive, rot-resistant lumber, as a landscape species, and for its value as a reliable food source for wildlife in native ecosystems (nut crops were generally produced every year). The nuts were used as food for both people and livestock and the wood was used for just about anything that was constructed of wood including furniture, utility poles, wood flooring, musical instruments, railroad ties, and caskets, and most barns and homes east of the Mississippi that were built between 1600 and 1900 were constructed from American chestnut lumber. But that was before the effects of the accidental, and very unfortunate introduction of the pathogenic fungus that causes chestnut blight to North America – Cryphonectria parasitica (formerly Endothia parasitica), a devastating fungus that colonizes the inner bark and cambium and causes expanding, deadly cankers on the trunks, stems, and shoots of American chestnut trees of all ages, began to appear. Thus far, no inherent resistance has been found in American chestnut populations.

First detected and reported in 1904 when diseased American chestnut trees were observed by a forester in New York City in the New York Zoological Park (now the Bronx Zoo), it is believed that the fungus was introduced on Japanese chestnut trees imported as nursery stock from Asia sometime in the late 1800's. Following its introduction and initial establishment, the disease spread rapidly, and chestnut blight has subsequently devastated the American chestnut population throughout its native range and, although not yet extirpated, the species has been classified as “functionally extinct” by the United States Department of Agriculture (USDA) since 1950. In his well-known Manual of Woody Landscape Plants: Their Identification, Ornamental Characteristics, Culture, Propagation and Uses, Dr. Michael Dirr describes American chestnut as “the queen of American forest trees” that has been “reduced to a memory” by chestnut blight. Today, occasional stumps that produce sprouts are all that remain of this revered species, but the young stems are soon attacked by the fungus and never reach reproductive maturity, so seeds are never produced and the species is no longer self-sustaining. Although less susceptible, Castanea pumila (synonym Castanea alnifolia; Allegheny chinquapin/chinkapin, American chinquapin/chinkapin, or dwarf chestnut), a much smaller tree or large shrub (attaining maximum heights of only 30 feet) that is native to the eastern and southeastern United States from southern New Jersey and Pennsylvania to northern Florida and west to eastern Texas and Oklahoma, is also vulnerable to attack by the chestnut blight fungus. Breeding and selection efforts have variously focused on the development of American and hybrid chestnut trees that are resistant to chestnut blight for decades with varying degrees of success, but no final solution.

Although traditional breeding and selection efforts continue, genetic engineering has received increasing attention as a method of developing blight resistant chestnut trees in recent years. A prominent example is the American Chestnut Research and Restoration Project (https://www.esf.edu/chestnut/), a nonprofit organization housed in the College of Environmental Science and Forestry (ESF) at the State University of New York, whose goal is to reintroduce resistant American chestnut trees into forest ecosystems in New York and the rest of the eastern United States, and ultimately restore American chestnut to its native range in North America, has been pursuing the development of blight resistant trees using genetic engineering techniques. Interestingly, and although other species of chestnuts (Castanea spp.), specifically Chinese chestnut (Castanea mollissima; native to China, Taiwan, and the Korean peninsula) and Japanese chestnut (Castanea crenata; also called Korean chestnut; native to Japan and South Korea), have genetic resistance to chestnut blight and have been used in breeding efforts to develop resistant chestnut trees with characteristics that are similar to the revered American chestnut, the gene that has been used to successfully confer blight resistance to American chestnut trees by ESF researchers comes from wheat (Triticum aestivum). Cryphonectria parasitica is an oxalate-producing fungal pathogen and the oxalic acid generated by the chestnut blight fungus weakens cell walls and creates an environment that allows other fungal enzymes to degrade cell walls and membranes which results in the death of cells, the formation of girdling cankers, and the death of the portions of the tree above the cankers. The gene that has been isolated from wheat provides codes the production of an enzyme called oxalate oxidase (OxO) which, when incorporated into the genome of American chestnut trees, confers genetic resistance to chestnut blight by preventing the formation of cankers by the chestnut blight fungus in transgenic chestnut trees by converting the harmful oxalic acid to carbon dioxide and hydrogen peroxide. Although trees can still be infected by the fungus, the infections are not viable and the addition of the OxO gene to the American chestnut genome and the subsequent oxidation of oxalic acid by the oxalate oxidase enzyme has been described by some as a vaccine against the chestnut blight fungus.

A process called Agrobacterium-mediated transformation is used to facilitate the gene transfer wherein a "disarmed" (non-pathogenic) strain of Agrobacterium tumefaciens containing the resistance enhancing OxO gene is used to transform somatic American chestnut embryos. Wild type Agrobacterium tumefaciens is a pathogenic bacterium that is commonly found in the soil and is a natural genetic engineer that is commonly used in transgenic research. Using traditional tissue culture techniques, these transgenic embryos can then be multiplied and triggered to produce shoots which are then rooted and grown on to produce chestnut blight resistant trees. By crossing these transgenic trees with surviving wild American chestnut trees, the researchers hope to maintain genetic diversity and regional adaptations of America chestnut populations in future generations of American chestnuts while also protecting them from chestnut blight with the ultimate goal of producing trees that can reach reproductive maturity and produce seeds and offspring to conserve and restore the American chestnut to its native range.

Compared to traditional breeding to create inter-specific hybrids between American chestnut and resistant species like Chinese chestnut, the transfer of the single gene that is responsible for the oxalate oxidase enzyme is much more targeted and precise than the thousands of genes that are involved in the creation of inter-specific hybrids through traditional breeding and selection efforts. As a result, the introduction of undesirable characteristics from the nonnative species is generally avoided such that the inherent characteristics of American chestnut are retained. Horizontal gene transfer (HGT; the transfer of genes between organisms in a manner other than traditional reproduction) between species, including the human-mediated transfer of the OxO gene from wheat to the American chestnut, is also a natural and random occurrence in nature via a variety of pathways and can have positive or negative effects on the genetically modified species depending on the circumstances. In addition to the development of blight resistant American chestnut trees Under controlled conditions, HGT may have the potential to be used to confer a number of traits to a variety of horticultural species including abiotic stress tolerances (e.g., drought, heat, flooding, and high pH tolerance), plant habit, unique flower forms, colors and fragrances, responses to day length and flowering times, herbicide resistance, and resistance to other diseases and pests.

Needless to say, although genetic engineering may show potential for a variety of desirable outcomes, the use of biotechnology, including the use of genetic engineering and the development of genetically modified trees and other plants for agricultural, landscape, and conservation purposes is controversial and the transgenic research focused on the iconic American chestnut has become the “poster child” for both the proponents and detractors of biotechnology and genetic engineering as a means of increasing tree and forest health. In response to the growing interest in genetic engineering and the associated concerns, the National Academies of Science, Engineering and Medicine has sponsored a review of the potential of biotechnology to address forest health concerns and has subsequently published a consensus study report entitled Forest Health and Biotechnology: Possibilities and Considerations (see “Citations” section) and may be of interest to nursery and landscape professionals that have an interest in these issues. In addition, in response to concerns about the American Chestnut Research and Restoration Project’s plans to eventually release genetically engineered American chestnut trees into the wild, the Campaign to STOP GE Trees, Biofuelwatch and Global Justice Ecology Project, an international alliance of organizations formed in 2004 and dedicated to stopping the release of genetically engineered trees based on a belief that such trees would have devastating ecological and social impacts, released a white paper in April of this year (2019) describing the science and potential risks of releasing genetically engineered American chestnut trees into forests. It is important to note that the ongoing ESF American chestnut research is regulated under a permit granted by the USDA and the potential deregulation and release of transgenic American chestnut trees into an unregulated environment would be subject to stringent regulatory review by the USDA and two other federal agencies – the US Environmental Protection Agency (EPA) and the US Food and Drug Administration (FDA). It must also be noted that the activities of these regulatory agencies are not universally respected by all concerned. Regardless, if the genetically engineered American chestnuts that are currently being developed are deregulated in the next few years, they would be the first genetically modified trees to be planted in the wild; a very big and potentially consequential development.

Public angst related to genetically modified food crops, and genetically modified organisms (GMOs) in general, is certainly understandable and often justified, and public perceptions are regularly influenced by a variety of factors including a lack of clear and reliable information regarding the history and current status of traditional breeding and genetic engineering techniques, safeguards, and outcomes, media bias and a steady stream of negative stories and opinions about genetically modified organisms in the news and popular media (including social media), a general, and seemingly growing, mistrust of industry and regulatory authorities, and strong and committed opposition to GMOs by vocal activist groups. Without question, public concerns about genetically engineered plants and other organisms must be addressed if the science and desired outcomes of genetic engineering are to be understood and realized and the nursery and landscape industry needs to be educated and involved relative to the genetic engineering research and activities that have the potential to impact our industry and the plants we provide to our customers. And as the science continues to move forward, it is clear that regulatory changes will also be needed to address the many new innovations that have occurred and the future changes to come and industry will need to decide how it will be involved in this process.

Finally, it should be noted that American chestnut has also been historically threatened by Phytophthora root rot caused by the fungus Phytophthora cinnamomi in the southern reaches of its native range and the development of viable selections and restored populations of American chestnut will likely require resistance to both pathogens. Obviously, this susceptibility to another serious disease complicates efforts to return American chestnut to its former status as an important landscape and forest tree and efforts are ongoing to hopefully accomplish this goal.

Clearly, the potential benefits that might be realized through genomic research and genetic engineering are exciting, but, at the same time, these emerging technologies also present significant, and understandable concerns and research and regulatory challenges. American chestnuts that have been genetically engineered to be blight resistant could be a good test case and may set a precedent and become a model for the future. It will be interesting to see where we end up.

Citations:

Powell, W.A., A.E. Newhouse, and V. Coffey. 2019. Developing Blight-Tolerant American

Chestnut Trees. Cold Spring Harbor Perspectives in Biology doi:10.1101/cshperspect.a034587 https://www.esf.edu/chestnut/documents/Cold%20Spring%20Harb%20Perspect.pdf

National Academies of Sciences, Engineering, and Medicine. 2019. Forest Health and Biotechnology: Possibilities and Considerations. The National Academies Press, Washington, DC. This publication may be purchased, downloaded for free in pdf form, or read online at https://doi.org/10.17226/25221 or https://www.nap.edu/catalog/25221/forest-health-and-biotechnology-possibilities-and-considerations

Smolker, R. and A. Petermann. 2019. Biotechnology for Forest Health? The Test Case of the Genetically Engineered American Chestnut. The Campaign to STOP GE Trees, Biofuelwatch and Global Justice Ecology Project. https://stopgetrees.org/wp-content/uploads/2019/04/biotechnology-for-forest-health-test-case-american-chestnut-report-WEB-1.pdf

The following, selected resources related to the genetic engineering of plants and the regulation of genetically modified plants may also be of interest:

Conolly, N.B. 2007 (updated January 2015). Chestnut Blight: Cryphonectria parasitica. Plant Disease Diagnostic Clinic, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY. http://plantclinic.cornell.edu/factsheets/chestnutblight.pdf

Van Laere, K., S.C. Hokanson, R. Contreras, and J. Van Huylenbroeck. 2018. Woody Ornamentals of the Temperate Zone. In: Van Huylenbroeck J. (ed.) Ornamental Crops. Handbook of Plant Breeding, Vol. 11. Pages 803-887. Springer, Cham. https://link.springer.com/chapter/10.1007/978-3-319-90698-0_29#citeas (abstract and references only)

Chang, S, E.L. Mahon, H.A. MacKay, W.H. Rottmann, S.H. Strauss, P.M. Pijut, W.A. Powell, V. Coffey, H. Lu, S.D. Mansfield, and T.J. Jones. 2018. In Vitro Cellular & Developmental Biology – Plant 54(4):341-376. https://link.springer.com/article/10.1007%2Fs11627-018-9914-1

Oliver, M.J. 2014. Why We Need GMO Crops in Agriculture. Missouri Medicine 111(6):492-507. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6173531/

Leyser, O. 2014. Moving Beyond the GM Debate. PLoS Biol 12(6): e1001887. https://doi.org/10.1371/journal.pbio.1001887

Stephen F. Chandler, S.F. and C. Sanchez. 2012. Genetic Modification; the Development of Transgenic Ornamental Plant Varieties. Plant Biotechnology Journal 10(8):891-903. https://onlinelibrary.wiley.com/doi/full/10.1111/j.1467-7652.2012.00693.x

Lucht, J.M. 2015. Public Acceptance of Plant Biotechnology and GM Crops. Viruses 7(8):4254-4281. https://www.mdpi.com/1999-4915/7/8/2819/htm

Herman, R.A., M. Zhuang, N.P. Storer, F. Cnudde, and B. Delaney. 2019. Risk-Only Assessment of Genetically Engineered Crops Is Risky. Trends in Plant Science 24(1):58-68. https://www.cell.com/trends/plant-science/fulltext/S1360-1385(18)30230-9

Prakash, C.S. 2001. The Genetically Modified Crop Debate in the Context of Agricultural Evolution. Plant Physiology 126(1):8-15. http://www.plantphysiol.org/content/plantphysiol/126/1/8.full.pdf

Westbrook, J.W., J.B. James, P.H. Sisco, J. Frampton, S. Lucas, and S.N. Jeffers. 2019. Resistance to Phytophthora cinnamomi in American Chestnut (Castanea dentata) Backcross Populations that Descended from Two Chinese Chestnut (Castanea mollissima) Sources of Resistance. Plant Disease 103(7):1631-1641. https://apsjournals.apsnet.org/doi/10.1094/PDIS-11-18-1976-RE (abstract only) https://apsjournals.apsnet.org/doi/10.1094/PDIS-11-18-1976-RE

United States Department of Agriculture (USDA). 2014. Plant Protection Act (As Amended, December 23, 2004). USDA, Animal and Plant Health Inspection Service (APHIS), Plant Protection and Quarantine (PPQ), Professional Development Center (PDC). https://www.aphis.usda.gov/plant_health/downloads/plant-protect-act.pdf

Executive Office of the President (EOP). 2016. National Strategy for Modernizing the Regulatory System for Biotechnology Products. https://obamawhitehouse.archives.gov/sites/default/files/microsites/ostp/biotech_national_strategy_final.pdf

Executive Office of the President (EOP). 2017. Modernizing the Regulatory System for Biotechnology Products: An Update to the Coordinated Framework for the Regulation of Biotechnology. https://obamawhitehouse.archives.gov/sites/default/files/microsites/ostp/2017_coordinated_framework_update.pdf

Montgomery, E. 2012. Genetically Modified Plants and Regulatory Loopholes and Weaknesses Under the Plant Protection Act. Vermont Law Review 37:351-379. https://lawreview.vermontlaw.edu/wp-content/uploads/2013/02/03-Montgomery1.pdf

Figure 1. An American chestnut (Castanea dentata) leaf showing its characteristic shape and distinctive teeth that are responsible for the specific epithet dentata (Latin for toothed); the emerging leaves are light green and lustrous with a reddish-purple tinge and long-pointed tips, becoming dark green as they mature (Photo Credit: James Calkins).

American Chestnut Leaf

Figure 2. American chestnut (Castanea dentata) fruits, catkin remnants, and leaves; American chestnut trees are monecious (male and female flowers produced on the same plant) and produce flowers on two types of catkins after the leaves emerge in the spring – catkins that produce only male flowers that bloom first, and catkins that produce male flowers along most of their length and several female flowers near their bases where the catkins are attached to the flowering shoots – and spine-covered fruits called burs (Photo Credit: James Calkins).

American Chestnut Fruits Catkin Remnants & Leaves

Figure 3. A young American chestnut (Castanea dentata) tree infected by American chestnut blight (Cryphonectria parasitica); note the distinct, orange canker surrounding a small dead, blighted side branch in the center of the canker that will eventually girdle and kill the stem above the canker and ultimately the entire stem (Photo Credit: Linda Haugen, USDA Forest Service, Bugwood.org).

Chestnut Blight Canker - Linda Haugen USDA

New Emerald Ash Borer (EAB) and Palmer Amaranth Finds in Minnesota

Fri, 5 Oct 2018 22:03:09 GMT

Emerald Ash Borer (EAB) Found in Wright County

On September 13, 2018, the Minnesota Department of Agriculture (MDA) announced the discovery of a new emerald ash borer (EAB; Agrilus planipennis) infestation in Wright County and has declared an emergency quarantine for the entire county....

Palmer Amaranth Discovered in Redwood County

In addition to the recent find of emerald ash borer (EAB) in Wright County in the Twin Cities metropolitan area, the Minnesota Department of Agriculture (MDA) has also confirmed a new infestation of Palmer amaranth (Amaranthus palmeri) in Redwood County in west-central Minnesota....

Click here to read more about the history of these finds and current details.

Help the University of Minnesota Develop a Gravel Bed Database

Tue, 29 May 2018 19:05:30 GMT

Minnesota has emerged as one of the national leaders in using gravel beds to help decrease transplant shock and increase the survival of transplanted nursery stock to reforest our communities and the University of Minnesota has been a leader in gravel bed research and promotion. A recognition that it would be helpful to all concerned to know who is using gravel beds and where they are located, the University of Minnesota would like to create a gravel bed database for Minnesota. Read full article.

Eau Claire County, Wisconsin, Added to Quarantined Area for Emerald Ash Borer (EAB)

Wed, 27 Dec 2017 17:09:40 GMT

Emerald ash borer (EAB; Agrilus planipennis) was discovered in the City of Eau Claire in Eau Claire County on November 27, 2017, and reported in a news release from the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) on December 4, 2017. As a result of this new find, the Eau Claire EAB infestation becomes the seventh new EAB infestation identified in Wisconsin outside previously quarantined areas, and Eau Claire County becomes the seventh county added to the Wisconsin quarantine list, since August (Chippewa, Eau Claire, Green Lake, Marathon, Marinette, Waupaca, and Waushara Counties). As has been previously reported, EAB has also been confirmed in only one new county in Minnesota during the same period (Martin County in August). The new infestation, located on the University of Wisconsin-Eau Claire campus in the heart of the City of Eau Claire, was investigated by Wisconsin Department of Natural Resources and City of Eau Claire forestry staff and was initially discovered in response to extensive damage to an ash tree caused by woodpeckers in search of EAB larvae under the bark. It was subsequently learned that several trees were involved and larval samples were submitted to the USDA Animal and Plant Health Inspection Service (APHIS) for official confirmation. The formal announcement of the Eau Claire County infestation and the addition of Eau Claire County to the list of quarantined counties in Wisconsin is available on the DATCP website at https://datcp.wi.gov/Pages/News_Media/EABEauClaire.aspx.

The City of Eau Claire, the County Seat of Eau Claire County, is located in west-central Wisconsin, 84 miles east of St. Paul, MN, along Interstate Highway 94 (I-94). Eau Claire County is bordered by Chippewa County to the north (recently quarantined for EAB), Buffalo, Trempealeau, and Jackson Counties to the south (all quarantined for EAB and contiguous with the quarantined counties in the southern half of the state), Clark County to the east, and Dunn and Pepin Counties to the west. Emerald ash borer has not yet been documented in neighboring Clark, Dunn, and Pepin Counties, but all three counties share a border with at least two other quarantined counties and Clark County is bordered by quarantined counties to the south, east, and west (five counties).

As nursery and landscape professionals are well aware, EAB is a serious threat to ash trees growing in designed landscapes and native ecosystems and Minnesota Nursery and Landscape Association (MNLA) members located in Wisconsin, and especially in the Eau Claire area, and member firms that perform work in Wisconsin, will want to be aware of this expansion of the EAB quarantine and continue to educate their customers about the threat of EAB and how to manage and prevent the spread of this devastating insect pest.

Including Eau Claire County, 49 of Wisconsin’s 72 counties (68%), including all of the counties in the southern half of the state, are now under quarantine for EAB. Although this is a depressing statistic, it is important to note that, with the exception of the far southeastern corner of the state and a few of the counties bordering Minnesota in the southwestern part of the state, most of Wisconsin, including most of the area in the quarantined counties, remains EAB-free, as a majority of the quarantined counties only have small, isolated EAB infestations. The same is also generally true for Minnesota where only 16 of the state’s 87 counties (18%), almost exclusively located in the Twin Cities metropolitan area and several counties in southeastern Minnesota, are currently under full or partial quarantine in an attempt to slow the spread of EAB in the state.

A list of confirmed EAB infestations in Wisconsin by county, municipality, and date of confirmation is available on the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) website at https://datcpservices.wisconsin.gov/eab/articleassets/ConfirmedEABFindsInWisconsin.pdf and a map of the Wisconsin counties quarantined for EAB can be found at https://datcpservices.wisconsin.gov/eab/articleassets/WI_EAB_Quarantine.pdf. See the link to the Minnesota Department of Agriculture (MDA) website below to view a map of the EAB infestations and quarantined areas in Minnesota.

Avoid moving firewood. It cannot be overemphasized that infested firewood is considered a primary vector of EAB and firewood may not be moved out of a quarantined county. Better yet, firewood should not be moved around the state or even within an infested county. In Minnesota, firewood may only be moved outside quarantined areas if it has been heat-treated to state standards and certified by the Minnesota Department of Agriculture under a compliance agreement. Additional information about moving firewood in Minnesota is available at http://www.mda.state.mn.us/plants/pestmanagement/firewood.aspx and at http://www.mda.state.mn.us/plants/pestmanagement/firewood/firewood-dealers.aspx. The Minnesota Department of Natural Resources also has firewood restrictions (http://www.dnr.state.mn.us/firewood/index.html). Information on moving firewood in Wisconsin is available at https://datcp.wi.gov/Pages/Programs_Services/MovingFirewood.aspx and from the Wisconsin Department of Natural Resources at http://dnr.wi.gov/topic/Invasives/firewood.html.

History of EAB in North America and in Minnesota and Neighboring States

Native to east-central Asia, emerald ash borer (EAB; Agrilus planipennis; Coleoptera: Buprestidae) was first documented in North America in 2002 in southeastern Michigan (Detroit area) and has since spread to 30 states in the Eastern, Midwestern (including Minnesota), and Mountain regions of the United States and the far southern portions of two Canadian provinces (Ontario and Quebec). Capable of attacking healthy trees, hundreds of millions of ash trees (Fraxinus spp.) have already been killed in infested areas and all three species of ash native to the Upper Midwest and Minnesota are susceptible to attack – white ash (Fraxinus americana), black ash (Fraxinus nigra; most common in northern Minnesota and the most numerous species in the state), and green ash (Fraxinus pennsylvanica; also called red ash; the most widely distributed species in the state and the most commonly planted species in designed landscapes). As a result, it is estimated that as many as one billion ash trees could be at risk in Minnesota alone.

In Minnesota, EAB was first documented in Ramsey County in 2009 (May); EAB was also confirmed in Hennepin and Houston Counties the same year and all three counties were subsequently quarantined by the Minnesota Department of Agriculture (MDA). Winona County was added to the list of quarantined counties in 2011. Since then, the destructive, non-native emerald ash borer beetle has continued to spread to new areas and, as of this writing, 16 of Minnesota’s 87 counties (18%) are currently subject to complete or partial quarantines in an attempt to prevent the spread of emerald ash borer in the state. Fifteen (15) counties are covered by complete quarantines including Anoka (2015), Chisago (2015), Dakota (2014), Dodge (2016), Fillmore (2015), Goodhue (2017), Hennepin (2009), Houston (2009), Martin (2017), Olmsted (2014), Ramsey (2009), Scott (2015), Wabasha (2016), Washington (2015), and Winona (2011) Counties. A partial quarantine (established in September 2016 and formalized in March 2017) is also in effect for southeastern St. Louis County.

Originally the quarantine in St. Louis County was limited to Park Point in the City of Duluth (November 2015), but has subsequently been expanded to include the southeastern portion of St. Louis County including the entire City of Duluth in response to additional EAB finds. The remainder of St. Louis County is not currently under quarantine. Superior, WI (Douglas County), is also infested and was quarantined in 2013. Although the infestations in Duluth, MN, and Superior, WI, are in areas where winter temperatures tend to be moderated by Lake Superior, these infestations are close to the larger populations of ash trees in the colder, more forested areas of both states. As a result, depending on the actual winter temperatures experienced, we may soon learn whether these infestations will be able to expand and affect ash trees in the adjacent, colder areas where laboratory studies have suggested EAB populations may not be able to reach tree-killing levels as a result of the winter temperatures typically experienced in these regions. With the exception of the City of Duluth and the recent find in Martin County, the current EAB infestations in Minnesota are limited to the Twin Cities metropolitan area and the southeastern corner of the state.

Fortunately the spread of EAB in Minnesota has been slower than what has been experienced in other infested areas and the new finds in Dodge, Martin, and Wabasha Counties, and the expanded quarantines in Goodhue and St. Louis Counties are the only new areas that have been added to the Minnesota EAB quarantine in 2016 and so far this year (2017). Of course, this may change as this is a time of year when new finds are common as a result of woodpecker activity focused on EAB larvae in infested trees as was recently the case in Eau Claire County, Wisconsin. Although the spread of EAB and the number of trees that have been lost in Minnesota have been atypical compared to the more easterly infestations in other states, it is possible that EAB is beginning to spread more quickly. Beginning with the first EAB finds in Minnesota in 2009, six (6) counties were quarantined during the first six years (2009-2014) of the Minnesota invasion, but, including the most recent find in Martin County in August of this year, quarantines have subsequently been added in ten (10) additional counties since then (2015-August 2017). Whether this trend continues remains to be seen.

Emerald ash borer is also present in Iowa (mainly in eastern and southern counties) and a few counties in east-central Nebraska, but has not yet been found in North or South Dakota. The Minnesota and Nebraska infestations, plus infestations in a small number of counties just across the state borders in eastern Kansas, Oklahoma, and Texas, and an isolated infestation in Boulder County, CO, are currently the western-most infestations in North America. In Canada, the EAB infestation is currently limited to extreme south-central Quebec and southeastern Ontario and an isolated infestation in the Thunder Bay, Ontario, area approximately 45 miles northeast of the Minnesota border. The introduction of EAB in North America, which likely occurred in the early 1990s, was a human-mediated event and, more recently, the long-distance and initially-isolated infestations of EAB in the Minneapolis/St. Paul metropolitan area, the Duluth/Superior area, Thunder Bay (Ontario, Canada), Rhinelander (WI), the Kansas City (MO/KS) metropolitan area, the southwestern Arkansas/northern Louisiana/northeast Texas region, and in Boulder County (CO), were almost certainly human-mediated introductions. Along with other control efforts, all concerned must be constantly diligent and take great care to avoid moving EAB-infested materials, including firewood, to non-infested areas to slow the spread of this devastating insect pest.

Selected Links to Additional EAB Information

General information about the Minnesota Department of Agriculture (MDA) emerald ash borer (EAB) program and links to more specific information about EAB in Minnesota are available on the MDA website at http://www.mda.state.mn.us/plants/pestmanagement/eab.aspx.

The text of the Minnesota EAB quarantine (Version 11; May 9, 2017) is available at http://www.mda.state.mn.us/plants/pestmanagement/eab/eabquarantine.aspx. The quarantine addresses the use and movement of regulated materials which include the insect itself (all life stages); all plants and plant parts of the genus Fraxinus, including nursery stock, scion and bud wood, logs, branches, stumps, and roots, chips and mulch (composted or not); firewood of any non-coniferous species, and other materials deemed to be a risk for the spread of EAB by the Minnesota Commissioner of Agriculture.

A new, interactive, searchable, ArcGIS online map of specific EAB finds and generally infested, quarantined, and biocontrol areas in Minnesota is available at https://mnag.maps.arcgis.com/apps/webappviewer/index.html?id=63ebb977e2924d27b9ef0787ecedf6e9.

A summary of the status of EAB in Minnesota, along with information about some of the activities being pursued by the MDA to better understand and track EAB in the state, are available at http://www.mda.state.mn.us/plants/pestmanagement/invasivesunit/~/media/Files/plants/invasives/statusrpt-eab.pdf.

Additional information about EAB in Wisconsin is available at http://datcpservices.wisconsin.gov/eab/article.jsp?topicid=20.

And finally, additional information regarding the status of EAB in North America is available on the Emerald Ash Borer Information Network website at http://emeraldashborer.info and from the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) at https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/emerald-ash-borer.

If you have questions or comments regarding this EAB quarantine update or the status of EAB in Minnesota and/or Wisconsin, contact Jim Calkins, MNLA Regulatory Affairs Manager, at jim@mnla.biz; 952-935-0682.

Good News: Green Industry Research Reported in the Journal of Environmental Horticulture is Now Open

Thu, 27 Jul 2017 17:11:40 GMT

Open access is an international initiative with the goal of making peer-reviewed research immediately available to other researchers, industry professionals, and the public free of charge. Making research findings available in an open access format improves the accessibility of peer-reviewed research by eliminating the economic barriers of access to published research findings and can also increase the timeliness and impact of the research reported. Read the full article.

Designing Landscapes to Mitigate the Negative Effects of Stormwater Runoff

Thu, 8 Jun 2017 15:41:28 GMT

Recent heavy rains are a clear reminder of the need to manage stormwater runoff and the role trees and other green infrastructure can play. Read the full article.

Deer Repellents Plus

Tue, 25 Apr 2017 15:36:10 GMT

Spring has arrived in Minnesota, resident deer are hungry, and landscape plants are at risk; deer repellents and other potential solutions. Read the full article.

Can Japanese Knotweed Reproduce by Seed in Minnesota?

Thu, 13 Apr 2017 15:54:36 GMT

Japanese knotweed (Polygonum cuspidatum), also called Asian knotweed, Japanese fleeceflower, and Mexican bamboo, and, to a much lesser extent, giant knotweed (Polygonum sachalinense), also called Sakhalin knotweed and Japanese bamboo, members of the Polygonaceae (Buckwheat, Knotweed, or Smartweed Family), are well-known herbaceous perennials that have been planted in American landscapes, including Minnesota landscapes, for over 100 years. Introduced from their native habitats in Asia, Japanese knotweed is native to Japan, eastern China, Taiwan, and the Korean peninsula, and giant knotweed is native to northern Japan and Sakhalin Island to the north (Russia). Both species are long-lived, rhizomatous geophytes that are cold hardy (USDA Cold Hardiness Zone 4) and otherwise quite adaptable (light, soil texture, and pH) and can spread aggressively by their rhizomes to produce large colonies if established in areas where the growing conditions are ideal (adequate light and moisture). Read full article.

Consider attending the 2017 Shade Tree Short Course; March 14-15 at Bethel University in Arden Hills

Wed, 8 Mar 2017 15:49:51 GMT

If it’s March, it must be time for the Shade Tree Short Course; a Minnesota tradition started in 1963. This year, the 55th Annual Shade Tree Short Course will take place on March 14-15, 2017, at Bethel University in Arden Hills, Minnesota.

The Shade Tree Short Course is two-day conference for anyone and everyone involved in urban forestry and arboriculture and interested in shade tree selection, health, and management. In addition to the valuable learning opportunities focused on a wide variety of topics related to shade trees, International Society of Arboriculture Certified Arborist CEUs will be available for most sessions and Certified Minnesota Tree Inspectors will be recertified by attending the conference. A combination of general and concurrent sessions covering a multiplicity of shade tree topics based on research and practical experience, and motivated by the desire to protect, maintain, and increase tree canopy in Minnesota communities, will be the highlight of each day. Read full article.

Turf Research: Establishing Better Lawns for People and the Environment

Fri, 17 Feb 2017 16:44:40 GMT

It has been estimated that there are nearly 42 million acres of lawn in the United States which accounts for 1.9% of the land area in the country. In Minnesota, the proportion of land dedicated to turfgrass is similar to that for the country as a whole – about 785,000 acres or just over 1.5% of the land area. Interestingly, in Minnesota, and all but nine states (Arkansas, Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, Utah, and Wyoming), it is estimated that turfgrass is the leader as an irrigated crop based on acreage; more than the top irrigated crops combined including corn, forage crops, soybeans, orchard and vineyard crops, cotton, pastureland, and wheat. Needless to say, managed turfgrass is an important commodity from a horticultural perspective and a significant component of managed landscapes where turf serves a variety of important functions including aesthetics, erosion control, and carbon sequestration just to name a few. At the same time, maintaining a healthy lawn requires significant and increasingly expensive inputs including water, fertilizer, energy, and labor and these requirements and their impacts on budgets and potential impacts on the environment have caused some to question the value of lawns in designed landscapes. Read full article.

The Search for Salt Tolerant Turf

Fri, 17 Feb 2017 16:40:47 GMT

Too often we forget that a tremendous amount of deicing salt is applied to our highways, streets, driveways, and sidewalks to make these surfaces safer for vehicles and pedestrians during the winter months by lowering the freezing point of water. Sodium chloride (NaCl) is the primary deicing salt used for this purpose and, although the amount of road salt applied varies from year to year based on weather conditions, it is estimated that between 15 and 22 million tons are applied each year in the 26 states impacted by snow and ice including Minnesota where about 350,000 tons are used in the seven county, Minneapolis/St. Paul metropolitan area alone each year based on 2007 reporting (government entities – 265,400 tons/season; commercial snow and ice management firms – 66,349 tons/season; homeowners and commercial property managers/packaged NaCl – 17,460 tons per season). It is interesting to note that the use of road salt was relatively uncommon until just after World War II and its use has subsequently increased steadily and substantially over the past seventy years. Read full article.

Never Underestimate the Value of Healthy Soil and Always Respect the Fundamental Nature of Soil in N

Fri, 17 Feb 2017 16:34:23 GMT

Too often we seem to overlook or ignore the value and significance of healthy soil to our profession and the plants we grow, maintain, and recommend to our customers and the general public. As green industry professionals we should, of course, know better and constantly strive to preserve its many functions in natural and managed ecosystems. Several new publications produced by soil scientists at Iowa State University in collaboration with the Natural Resources Conservation Service (NCRS; United States Department of Agriculture/USDA) provide a wealth of information that should be of interest to growers, garden center staff, landscape designers, landscape managers, and the general public. Read full article.

Invasive Garden Ants; A Spreading Concern in Europe, Asia, and Beyond

Tue, 8 Nov 2016 15:50:23 GMT

Invasive garden ants (Lasius neglectus); a spreading concern in Europe, Asia, and beyond.They are a nuisance and a threat to human infrastructure, indigenous ant species (and possibly other native invertebrates), and native ecosystems, and may also be a potential threat to agriculture and managed landscapes. Read full article.

Threatening Disease of Commercial Banana in Designed Landscapes

Tue, 11 Oct 2016 17:39:40 GMT

Bananas (Musa spp.) are increasingly being used in designed landscapes, but may be threatened by a devastating disease. Most nursery, landscape, and garden center professionals have probably never heard of Panama disease, a Fusarium wilt disease caused by the ascomycete fungus Fusarium oxysporum f. sp. cubense. Most likely, this is because Panama disease is a disease of banana plants (Musa spp.) which are, of course, fairly uncommon in Minnesota. In recent years, however, this has been changing. Read full article.

Researchers, Policymakers, Green Industry Professionals, and Concerned Citizens Remain Interested in

Tue, 13 Sep 2016 17:19:29 GMT

As most nursery and landscape professionals are well aware, the ongoing debate about neonicotinoid insecticides and their potential impacts on bees and other pollinators continues. Much has been learned, but many important questions remain and researchers continue the search for answers to these questions. Read more.

Latest Invasive Species Research at UMISC

Thu, 4 Aug 2016 19:11:42 GMT

Keep up with the latest invasive species research at UMISC in La Crosse, Wisconsin, October 16-19, 2016. Read full article.

Discovery Early Bud-Break 1 Believed To Be “Master Regulator"

Wed, 3 Aug 2016 18:39:57 GMT

Recently discovered Early Bud-Break 1 (EBB1) gene believed to be a “master regulator” of spring bud-break in poplar trees (Populus spp.). Read full article.

Prominent Lifestyle and Landscape Design Trends in 2016

Tue, 5 Jul 2016 18:31:20 GMT

One of the keys to success for landscape design and construction firms is understanding the market – the interests and desires of potential customers – and having the skills to create landscape design solutions that address those needs. According to Missy Henriksen, vice president of public affairs for the National Association of Landscape Professionals (NALP), the latest landscape design trends highlight a desire by homeowners to “bring the indoors out” and “create comfortable landscapes that are both functional and beautiful” and suggest “a shift toward sustainable landscapes that reflect a renewed sense of mindfulness for the earth and its ecosystems.” Ms. Henriksen’s belief is based on an NALP analysis of the top landscape design trends for 2016. The annual trend analysis and predictions are based on consumer demands, lifestyle trends, and a variety of horticultural, architectural, and landscape design factors.

Recognizing and responding to these types of market trends in the proper context can be a challenge for nursery and landscape professionals, but these outcomes are essential if consumer interests and desires are to be anticipated and satisfied. Information gathered through consumer research, including the NALP survey completed earlier this year, can be helpful in this regard. Read more.

New Comprehensive Listing of Willow Cultivars

Mon, 13 Jun 2016 18:38:06 GMT

With the exception of quaking aspen (Populus tremuloides) in parts of the Mountain West, where it is revered and commonly planted in urban areas where it often isn’t very happy and tends to be short-lived, much like paper birch (Betula papyrifera; Betulaceae – Birch Family) in the Upper Midwest, the Salicaceae (Willow Family), which includes the willows, poplars, aspens, and cottonwoods (and other genera), are a group of plants people tend to love to hate. The current bias against this environmentally and culturally significant group of plants that have been important to humans for thousands of years is variously, but questionably, based on a variety of perceived concerns including disease and insect problems, weak wood that can be susceptible to breakage in storms, short lifespans, and a lack of showy landscape characteristics. In addition, some species have a suckering habit and some are considered messy (dropped leaves, twigs, flowers, fruits, and seeds; including, of course, the “cotton” associated with female cottonwood trees, but also variously produced by all members of the Salicaceae). In reality, many of these concerns are overblown and, in many cases, apply equally to other, more popular, species where these drawbacks tend to be accepted or overlooked. Phytobigotry aside, the bias against this important group of plants may be changing as the value of these plants is increasingly recognized and understood.New, comprehensive listing of willow cultivars may be of interest to plant breeders and others with an interest in the genus Salix. Read full article.

Production System Influences Production

Tue, 10 May 2016 16:51:21 GMT

Understanding the costs associated with producing, transporting, planting, establishing, and maintaining landscape plants is an important consideration for growers and their customers at the wholesale and retail level and regardless if the plants will be planted and maintained in the public or private sector. This is especially true in an economy where the cost of doing business continues to rise in response to increased production, distribution, marketing, and regulatory costs and where the financial resources of customers are increasingly limited resulting in a production and marketing environment that is increasingly competitive. Read full article.

UMISC CONFERENCE & LAF SUMMIT

Tue, 10 May 2016 16:45:06 GMT

As a follow up to a Research for the Real World Social Media Research Update posted earlier this year (Upper Midwest Invasive Species Conference to be held in La Crosse, WI – October 17-19, 2016), registration for the 2016 Upper Midwest Invasive Species Conference (UMISC) in La Crosse, Wisconsin, is now open. Held every other year, the conference is scheduled for October 17-19, 2016, and will focus on the latest tools and state-of-the-art techniques related to invasive species management. The conference is hosted by the Invasive Plants Association of Wisconsin (IPAW), the Midwest Invasive Plant Network (MIPN), and the Minnesota Invasive Species Advisory Council (MISAC). Read the full article.

Key Findings Related to the Marketing Activities and Perspectives of Garden Retailers

Mon, 4 Apr 2016 16:50:54 GMT

As garden center marketing efforts ramp up; survey data shows websites rank as the most successful marketing platform for garden retailers. Read full article.

Preliminary Risk Assessment Indicates Imidacloprid May Have A Negative Effect On Honey Bees

Mon, 7 Mar 2016 17:49:49 GMT

As part of an ongoing registration review of neonicotinoid insecticides the United States Environmental Protection Agency (USEPA/EPA) has released a preliminary risk assessment for imidacloprid (N-{1-[(6-Chloro-3-pyridyl)methyl]-4,5-dihydroimidazol-2-yl}nitramide). Imidacloprid was initially approved for use in the United States by the USEPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) in 1994. With the goal of ensuring that registered pesticides do not present an unreasonable risk to human health or the environment when used as directed on the product label, the USEPA has initiated a pesticide registration review program designed to reassess registered pesticides every 15 years to determine whether they continue to meet FIFRA standards for registration based on the most recent scientific data and other information. Read full article.