D. Michael Benson

This project addresses Goal 4, Safeguarding Nursery Production, by studying the basic factors influencing disease development and spread of boxwood blight caused by Calonectria pseudonaviculata (C.ps.). In the U.S., boxwood blight rapidly emerged as a destructive pathogen of boxwood during the fall of 2011, quickly impacting major boxwood production regions over a period of less than four months. The rapid spread of boxwood blight caught the nursery and landscape sectors of U.S. agriculture off-guard and ill-equipped to effectively manage the disease. In conjunction with developing mitigation strategies, it is imperative to understand the environmental factors which influence incidence and spread of this exotic disease in order to develop a systems approach to manage Boxwood Blight. This proposed regional, multistate collaborative research project will serve to safeguard nursery production in the United States by: 1. Determining inoculum sources, survival, and dissemination. 2. Studying the environmental parameters contributing to boxwood blight disease development and pathogen dispersal; 3. Evaluating the potential for root infections; and 4. Assessing the genetic diversity of strains and isolates. Collaboration among the five university, experiment station, and USDA research groups, in cooperation with the nursery industry (ANLA), ensures an integrated, coordinated effort toward the common goal of improved management of boxwood blight disease, without duplication of resources. Data and resource sharing between research groups will provide a robust common platform that will accelerate rapid discovery on a scale not possible from any individual laboratory. A complementary project entitled ?Boxwood Blight Mitigation Strategies? that will develop mitigation strategies and provide expanded outreach will be submitted separately under Goal 6.

This project addresses Goal 6, Enhance Mitigation Capabilities, through the development of integrated management tools that will minimize the incidence, severity and spread of boxwood blight disease caused by Calonectria pseudonaviculata (C.ps.) to boxwood plants (genus Buxus). Boxwood blight was first described in the United Kingdom during the 1990s and is now considered endemic throughout Europe. In the U.S., boxwood blight rapidly emerged as a destructive pathogen of boxwood during the end of 2011, quickly impacting major boxwood production regions over a period of less than four months. The rapid spread of boxwood blight caught the nursery and landscape sectors of U.S. agriculture off-guard and ill-equipped to effectively manage the disease. This proposed regional, multistate collaborative research project will enhance mitigation capabilities for boxwood blight disease in the United States by: 1. Identification of best management practices for boxwood blight in the U.S. using an integrated toolbox of conventional fungicides, biologically-compatible products, sanitizers, tolerant Buxus cultivars, and changes in cultural practices; 2. Development and implementation of a rapid molecular diagnostic tool for the identification of the fungicide-resistant G2 genotype; and 3. Developing outreach tools to educate growers on these best management practices. Collaboration among the IR-4 Project, seven university, experiment station, and USDA research groups, in cooperation with the nursery industry (ANLA), ensures an integrated, coordinated effort toward the common goal of improved management of boxwood blight disease, without duplication of resources. Data and resource sharing between research groups will provide a robust platform that will accelerate rapid discovery on a scale not possible from any individual laboratory. A complementary project entitled ?Understanding Environmental Factors for Boxwood Blight Development? that will study the environmental factors for boxwood blight development will be submitted separately under Goal 4.

This project addresses the development of integrated management tools that will minimize the incidence, severity and spread of boxwood blight disease caused by Cylindrocladium pseudonaviculatum (syn. C. buxicola) to boxwood plants (genus Buxus). Boxwood blight was first described in the United Kingdom during the 1990s and is now considered endemic throughout Europe. In the U.S., boxwood blight rapidly emerged as a destructive pathogen of boxwood during the end of 2011, quickly spreading across both major boxwood nursery production regions over a period of less than four months. The rapid spread of boxwood blight caught the nursery and landscape sectors of U.S. agriculture unaware and ill-equipped to effectively manage the disease. This proposed research project will serve to enhance mitigation capabilities for boxwood blight disease in North Carolina.

Fraser fir cultured as Christmas trees is one of North Carolina?s largest specialty crops with an annual revenue exceeding $100 million. The most severe disease in Fraser fir nurseries and plantations is Phytophthora root rot which afflicts the industry with an estimated $6 million in losses annually. Because Fraser fir has no innate resistance, the NCSU Christmas Tree Genetics Program has begun evaluation of two exotic species, Turkish and Trojan fir, that show promise as quality Christmas tree species and also possess some Phytophthora resistance. Genetic control of resistance to a single Phytophthora genotype has been confirmed. The proposed research will assess resistance in these fir species to a broader array of Phytophthora genotypes and use next generation sequencing technology to develop DNA markers to select for resistance in genetic field trials that will be established in 2013-2014. The technology and knowledge generated will be applied toward developing Phytophthora-resistant fir planting stock targeted for sites with known disease problems and will ultimately abate the adverse impact of this disease on the state?s Christmas tree industry.

Phytophthora diseases have become a major problem in floral crops throughout the United States in recent years due to movement of infected plant material between greenhouse production facilities and the ability of the pathogen to become established in production facilities once introduced. Surveys of production facilities have identified P. nicotianae as the most commonly occurring Phytophthora sp. on a number of different crops but P. drechsleri, P. cryptogea and P. tropicalis also occur. A high percentage of isolates of P. nicotianae and P. drechsleri are resistant to the most commonly used fungicide, mefenoxam. Phytophthora tropicalis, a recently described species in Hawaii, is becoming more prevalent on many different floral crops across the entire U. S. Floral crop growers need disease management information and tools to reduce or eliminate losses due to Phytophthora diseases.

Determine efficacy of new active ingredient formulations and new biopesticides for managing foliar and/or floral blights of ornamental plants caused by Botrytis species.

This research and extension project aims to enhance mitigation capabilities of boxwood blight through the evaluation and development of integrated management tools that will minimize the incidence, severity and spread of boxwood blight disease in field production of boxwood plants. We also plan on producing and developing outreach tools to educate growers and other extension agents on the best management practices for boxwood blight. Bulletins on boxwood blight and best management practices (BMPs) based on knowledge garnered so far have been developed by NCSU and other groups, but no research at current has focused on field production of boxwood.

This project addresses Goal 6, Enhance Mitigation Capabilities, through the development of integrated management tools that will minimize the incidence, severity and spread of boxwood blight disease caused by Cylindrocladium pseudonaviculatum (syn. C. buxicola) to boxwood plants (genus Buxus). Boxwood blight was first described in the United Kingdom during the 1990s and is now considered endemic throughout Europe. In the U.S., boxwood blight rapidly emerged as a destructive pathogen of boxwood during the end of 2011, quickly spreading across both major boxwood nursery production regions over a period of less than four months. The rapid spread of boxwood blight caught the nursery and landscape sectors of U.S. agriculture unaware and ill-equipped to effectively manage the disease. This proposed regional, multistate collaborative research project will serve to enhance mitigation capabilities for boxwood blight disease in the United States by: 1. Identification of best management practices for boxwood blight in the U.S. using an integrated toolbox of conventional fungicides, biologically-compatible products, sanitizers, tolerant Buxus cultivars, and changes in cultural practices; 2. Determination of the environmental parameters contributing to boxwood blight disease development and pathogen dispersal; 3. Development and validation of sensitive, rapid and accurate molecular diagnostic tools for the boxwood blight pathogen.

Efficacy of management tools for Pythium root rot in ornamental crops. Determine efficacy of new active ingredient formulations and new biopesticides for managing root, crown and stem rots of ornamental plants caused by Pythium species, so that growers will have new management tools to combat this disease problem.

Efficacy of management tools for Pythium root rot in ornamental crops. Determine efficacy of new active ingredient formulations and new biopesticides for managing root, crown and stem rots of ornamental plants caused by Pythium species, so that growers will have new management tools to combat this disease problem.