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Robert Jetton

Associate Professor & Camcore Forest Health Specialist

Jordan Hall Addition 3227



B.S. Furman University (1997)
M.S. North Carolina State University (2002)
Ph.D. North Carolina State University (2008)

Research Interests

Forest entomology; Invasive forest pests; Community ecology; Arthropod diversity related to habitat type and structure; Gene conservation; Population genetics

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Area(s) of Expertise

Gene Conservation and Forest entomology/pathology


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Date: 06/06/22 - 5/31/25
Amount: $34,234.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

Previous and ongoing research shows that cutting gaps around individual or small groups of hemlock woolly adelgid (HWA) infested eastern hemlocks to increase the level of sunlight exposure to the crown reduces HWA densities and improves the growth and carbon balance of the tree. How to apply and combine such release strategies with other HWA management tools remains unclear. This project will develop and validate silvicultural thinning tool that will be integrated with existing HWA chemical and biological control strategies to improve the health and long-term sustainability of eastern hemlock in the southern Appalachians.

Date: 09/16/19 - 7/25/24
Amount: $80,000.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

This agreement supports a cooperative project between North Carolina State University and the USDA Forest Service Southern Region for the genetic resource conservation of threatened and endangered tree species in the Southern Region, on the Southern Appalachian forests. Genetic diversity studies are critical in understanding adaptation of imperiled tree species to climate change and forest health impacts. This agreement will allow NCSU, Camcore to identify and add new imperiled tree species to the list for new seed collections. Genetic diversity studies will be done on the species and seeds will be used in restoration efforts on the Southern National Forests.

Date: 01/01/22 - 12/31/23
Amount: $150,000.00
Funding Agencies: US Dept. of Agriculture - Agricultural Marketing Service (USDA AMS)

This project will be a collaboration between the Christmas Tree Genetics Program, the Forest Health and Conservation Program, and the Molecular Tree Breeding Lab in the Department of Forestry and Environmental Resources at North Carolina State University. Our goal is to accelerate the genetic improvement of Fraser fir against the tree-killing pathogen Phytophthora root rot and insect pest balsam woolly adelgid. Fraser fir is one of North Carolina’s most important specialty crops generating annual revenues exceeding $100 million. The development of novel genomic tools and technologies will have a positive, transformative impact on the North Carolina Christmas tree industry. Our project builds on resources developed by the NCSU Christmas Tree Genetics Program in collaboration with the NCDA and NC Christmas tree growers over the past 4+ decades. We propose five major objectives in this proposal: (1) genomic resource development of Fraser fir responses to Phytophthora and BWA; (2) identification of Phytophthora and BWA elicitors; (3) evaluation of Fraser fir responses to isolated elicitors; (4) population level analysis of key pest responsive genes in existing NCSU Fraser fir breeding program resources; and (5) synthesis and dissemination of results to NC Christmas tree stakeholders. Subsequent to the funding period, these efforts will benefit the North Carolina Christmas tree community and contribute to the genetic conservation of native Fraser fir populations in the Appalachian Mountains. We expect project deliverables will help address key knowledge gaps of pest resilience in Fraser fir and push conventional conifer breeding strategies and integration with genomic information into a new era.

Date: 03/31/21 - 9/30/23
Amount: $2,800.00
Funding Agencies: Institute of Museum & Library Services

The Center for Plant Conservation received a grant from the Institute for Museum and Library Services (IMLS) for a project entitled, “RNA integrity as a powerful metric of aging in preserved seed collections of wild rare plant species” (MG-245983-OMS-20). To satisfy grant commitments, CPC has the need for a subcontractor to collect a “fresh accession” of rare plant seed from the same wild population previously collected 15 years ago or more and subsequently preserved in orthodox seed storage. The older seed accession currently in orthodox storage will hereafter be known as the “original accession”. Contractor represents that they are able and willing to undertake this work. As the contractor, NC State University will make one “fresh” seed collection from populations of Fraser fir (Abies fraseri) in western North Carolina. Fresh collections will either be made from the same population as the “original accessions”; from ex-situ plants of shared wild provenance; or from plants grown or bulked from seeds of a seed collection held in long term storage for 15 years or more – known as the “original accession.” The specific quantity of seed required for testing may vary depending on the size of seed and inclusion in the different experimental groups. Seed quantities for target species are the estimated quantity of seed needed to achieve 75mg of material plus 100 seeds for a germination trial. The bolded species will need multiple 75mg replicates from the freshly collected accession for inclusion in an advanced aging study.

Date: 05/01/21 - 4/30/23
Amount: $50,988.00
Funding Agencies: US Dept. of Agriculture (USDA) Forest Service

A monitoring program for Carolina hemlock ecosystems will be implemented across the species range. Vulnerability will be assessed using long-term growth, climate, and insect infestation patterns. Growth and mortality rates from the spatially extensive empirical data will be tested against Carolina hemlock status conditions from the Forest Inventory and Analysis program data.

Date: 11/01/21 - 10/31/22
Amount: $3,000.00
Funding Agencies: NC Christmas Tree Association

The research proposed will test Coretect, and imidacloprid-based insecticide, as a planting time treatment for multi-year control of piercing-sucking insect pests of Fraser fir Christmas trees. Pests such as the balsam woolly adelgid, balsam twig aphid, and elongate hemlock scale are important pests that routinely require regular application of foliar applied insecticides multiple times throughout a rotation for effective control. In pest management systems for other conifer species, a single CoreTect tablet placed in the planting hole provides four to five years of protection against most piercing-sucking insects. This project will test for similar effectiveness in Fraser fir. Reduced usage of foliar applied insecticides during the first four to five years of a rotation could yield significant financial savings for growers and reduce human and environmental pesticide exposure.

Date: 10/01/17 - 8/31/22
Amount: $25,000.00
Funding Agencies: Cary, NC

Located in the heart of Cary, North Carolina, Hemlock Bluffs Nature Preserve is an important ecological, cultural, and recreational resource for the local community. In addition to providing trails and education programs that allow people of all ages to become more familiar with the natural word that surrounds their daily lives, the unique geology of this Piedmont site creates a home for plant species more typical of the mountains of western North Carolina such as galax, and provides refuge for numerous species of reptiles, amphibians, mammals, arachnids, and insects against the ongoing urbanization of Cary. At the center of this unique ecosystem is eastern hemlock (Tsuga canadensis), a tree species known as the “redwood of the east” that is a canopy dominant species in the forests of the Southern Appalachian, mid-Atlantic, northeastern, and upper mid-western regions of the United States. At Hemlock Bluffs it is a relic of past glacial periods when many northern and mountain tree species survived below glacial margins in the Piedmont and coastal regions of the southeast. As the glaciers retreated many of these tree species migrated to areas now considered to be their natural environments, but the cool, moist environment of the north-facing bluffs along Swift Creek provides a niche where this small population of eastern hemlock is able to survive more than 200 miles distant from its typical habitat. The hemlock woolly adelgid (Adelges tsugae) is an exotic insect from Japan that has caused widespread decline and mortality of eastern hemlock throughout its native range in the eastern United States and threatens the extinction of this keystone forest tree species. Although initial predictions suggested that the isolation of Hemlock Bluffs from the core of the hemlock range would make introduction of this destructive insect unlikely, the adelgid was detected at the preserve in 2010. Since that time, the Town of Cary has worked closely with Bartlett Tree Experts and research and forest health management professionals from North Carolina State University, the North Carolina Forest Service, and the USDA Forest Service to develop a management strategy to limit the impact of the hemlock woolly adelgid at Hemlock Bluffs. So far, the combination of careful adelgid population monitoring and 2 use of chemical insecticides to control the insect when found has worked well. However, much of what we know about the long-term management of this pest comes from research and development activities developed for forests within the core of the eastern hemlock range. Given the unique nature of this Piedmont location and the growing influence of surrounding urbanization, research aimed at developing a better understanding of the genetic and ecosystem processes at this site will allow for the development of management and conservation strategies tailored specifically for Hemlock Bluffs Nature Preserve. This proposal documents three research projects that the Camcore program at North Carolina State University, in collaboration with our university, state, and federal cooperators, feel will aid in improving the long-term sustainability of Cary’s eastern hemlock resources.

Date: 12/02/21 - 7/31/22
Amount: $2,587.00
Funding Agencies: Christmas Tree Promotion Board

In collaboration with scientists at North Carolina State University and USDA ARS, scientists at Washington State University will utilize detached branches to determine the potential effectiveness of postharvest fumigation treatments with Bluefume (HCN) in killing elongated hemlock scale (EHS) life stages on infested Fraser fir and determine the effects of HCN fumigation on the postharvest quality of non-infested commonly-grown Christmas tree species,such as balsam fir, Canaan fir, Fraser fir, grand fir, noble fir, Nordmann fir, Turkish fir, Trojan fir, and Douglas-fir). Branches will be fumigated at the USDA ARS Postharvest facility in CA. Treatments will consist of 5 rates of HCN plus a non-fumigated control. Each treatment will be replicated 3 times with 3 branches per replication. Following fumigation, the viability of EHS life stages on infested branches will be assessed. Uninfested branches from the commonly grown species will be transported and displayed in a temperature-controlled room to determine if the fumigation treatments have any adverse effects on postharvest quality and needle retention.

Date: 07/03/17 - 7/02/22
Amount: $225,237.00
Funding Agencies: US Forest Service

This project will develop and validate a silvicultural tool that improves the health and sustainability of eastern hemlock, an ecologically keystone species in the southern Appalachians threatened by the invasive hemlock woolly adelgid (HWA). Individual or small clusters of "target" trees (i.e., suppressed or intermediate eastern hemlocks with moderate to good crown health) will be released by removing or girdling other stems competing for sunlight directly above and adjacent to the target trees. Increased sunlight is expected to improve hemlock crown health via improved carbon balance, enhanced foliage production, and reduced HWA settlement rates relative to unreleased trees. Treatments will be replicated at a number southern Appalachian sites and will evaluate release by girdling vs. felling and variations on the size of the resulting canopy gap. Operationally, the tool is expected to prolong hemlock health and survival and increase the efficacy of existing HWA management tools (e.g. biological and chemical control) when integrated with them.

Date: 01/01/20 - 6/30/22
Amount: $122,800.00
Funding Agencies: US Dept. of Agriculture (USDA)

The Department of Forestry and Environmental Resources at North Carolina State University will conduct field, greenhouse and laboratory studies to improve our understanding of the ecology and management of the exotic insect pest Elongate Hemlock Scale in Fraser fir Christmas trees, one of North Carolina’s most important specialty crops. Although the scale typically causes little damage to Fraser fir, its presence on Christmas trees represents an important pathway by which this insect can spread to new areas where more susceptible host species might exist. When detected on Christmas trees entering states where the scale is not yet present, local regulatory agencies intercept and destroy the infested material. This causes detriment to the revenues and reputation of North Carolina’s Christmas tree industry. The results of this research will inform management recommendations to growers for reducing scale infestations and limiting the risk of future spread via infested Fraser fir. Outcomes will be reported to stakeholders through presentations at the North Carolina Christmas Tree Association (NCCTA), articles in Limbs and Needles (the official trade magazine of the NCCTA), and papers published in the scientific literature.

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