Enhance Tennessee's nursery and ornamental plant industry

Research to keep a major industry strong


Sustainable Management of Arthropod Pests in Ornamental Nursery Production

Management of Invasive Non-Indigenous and Key Insect Pests in Nursery Crops 

Identification of Plant Endophytes for Plant Protection Against Fungal Diseases, Pests and Environmental Stresses

Improving Productivity and Soil-borne Disease Control in Nursery Crop Production

Improving Profitability and Reducing Negative Environmental Impacts of Nursery Crops


Sustainable Management of Arthropod Pests in Ornamental Nursery Production
Dr. Karla Addesso
The most recent comprehensive evaluation of the United States environmental horticulture industry reported economic  contributions of $147.8 billion in output, 1,964,339 jobs, $95.1 billion in value added, $64.3 billion in labor income, and $6.9 billion in indirect business taxes (Hall et al. 2005). Nursery and greenhouse crops alone account for $16 billion of the United States economy with $4.65 billion contributed by nursery growers reporting over $10,000 in sales (USDA 2007) and the sector provided 261,408 jobs with a value of $18.1 billion (Hall et al. 2005). As in other areas of agriculture, insect pest management programs are crucial to the production of healthy nursery stock, but despite the industry's considerable contribution to the United States economy, research on nursery crop pests lags behind in effort and funding focused on vegetables and row crops. The complex nature of the nursery industry due to the large number of plant species grown in individual nurseries is part of what makes nursery pest management research challenging. As such, pests that have large economic impacts, attack multiple, high production genera and are quarantine restricted are important targets for research.  Integrated pest management (IPM) programs that incorporate host plant resistance, cultural, behavioral and chemical controls are more sustainable than programs focusing on only one of these techniques. A key element in developing successful IPM programs is a thorough understanding of insect behavior and chemical ecology. By understanding pest behaviors and identifying the chemicals influencing those behaviors, pest managers can target pests at vulnerable stages in their life cycle and manipulate pest populations so they can be more effectively controlled. In 2009, the Southern Nursery Integrated Pest Management Working Group, sponsored by a grant from the Southern Region IPM Center, established the Pest Management Strategic Plan for Container and Field-Produced Nursery Crops. The working group consisted of a team of researchers and nursery owners. They listed the following research priorities for the nursery industries in Tennessee, Kentucky, North Carolina, South Carolina and Georgia, all of which support the need for research in the areas relating to: (1) making IPM profitable and viable for nursery crop production, (2) investigating whole systems approaches to pest management and (3) development of conservation biological control tactics, such as habitat manipulation with flowering plants, to increase the abundance, diversity, and efficacy of naturally occurring predators and parasitoids.  To support these strategic goals, we will focus resources on the study of arthropod pests that impact a wide range of high value woody ornamental crops. These pests may include spider mites, scales, wood borers, fire ants and other pests each of which affect a wide range of trees and shrubs. Two objectives will be investigated in the current Evans-Allen proposal: (1) Investigation of life history and behavioral traits of ornamental pests and associates to improve management and (2) Investigation of lower risk products for use against ornamental pests.

Management of Invasive Non-Indigenous and Key Insect Pests in Nursery Crops  
Dr. Jason Oliver
The U.S. green industry contributes about $150 billion in economic output and 1.9 million jobs to the U.S. economy with an estimated $6.4 billion contribution to the Tennessee economy. With more than 2,000 non-indigenous insects now introduced into the U.S. and a continued rapid influx of new species from global trade, the nursery industry has been significantly impacted by multiple new pest problems that result in higher production costs. Managing these new pests often requires frequent agrochemical inputs that increase environmental contamination, worker exposure hazards, and the carbon footprint of the nursery industry, which lowers long-term sustainability. The primary objective of this project is to develop more cost sustainable and environmentally-friendly management treatments for two problem groups of nursery insects including pests under Federal and state quarantines (i.e., imported fire ants [IFA] and Japanese beetle [JB]) and trunk attacking wood-boring insects (i.e., ambrosia beetles and flatheaded borers). Reasons for addressing these pest insect groups include 1) the mandatory protocols for JB and IFA that are expensive, impractical to apply, and primarily utilize older and more hazardous organophosphate chemistries, 2) the human and livestock health hazard, as well as ecological impact posed by IFA, and 3) the difficulty in management of wood-boring insects that are cryptically hidden in tree trunks, require multiple expensive treatments that are only moderately effective, are primarily non-native and lack current control programs and recommendations, and have damage that either kills trees or renders them unsalable (i.e., key pests). There have been an estimated 30 new Scolytinae bark and ambrosia beetles introduced into the U.S. since 1980, and JB and IFA are continuing to expand their U.S. range impacting new areas.  American Hort (formerly the American Nursery and Landscape Association) has cited the need for improved crop protection and control methods, systems approaches, and integrated Best Management practices to reduce the introduction of non-native pests and to manage established pests. American Hort also has stated a particular need for better pest control measures that minimize environmental and applicator hazards and improves industry sustainability. This project will address American Hort identified needs by developing new treatment options for key and invasive pests of field- and container-grown nurseries.  Insecticides and alternative biopesticides will be evaluated for the key invasive pests groups identified. To develop lower impact management programs, research will examine 1) lower than labeled rates of conventional insecticides alone or in combination with efficacy enhancing additives, 2) reduced-risk compounds (e.g., biological compounds, biopesticides) posing less acute hazard to nursery labor and the environment, and 3) improved time-saving application techniques. The project also will continue phorid-decapitating fly (Pseudacteon spp.) releases that have the potential to provide region-wide and sustainable biological suppression of IFA populations; thereby reducing IFA impacts on humans, livestock, and natural ecosystems, as well as lowering agrochemical inputs. Several possible impacts are expected from the project, including 1) new lower cost rates or treatment options available for JB, IFA, and other invasive pests to improve sustainability and profitability of small-limited-use, as well as large-scale nursery operations, 2) more reduced-risk biopesticides available for these pests, which in turn will reduce worker hazard and lower environmental contamination, 3) new IFA biological control agents that may provide region-wide, sustainable, and continued no cost suppression of IFA populations, and 4) improved sustainability of nurseries by lowering the utilization of synthetic petroleum-based insecticides that have a greater carbon footprint. This project also will address two of the seven priority areas identified by USDA-NIFA for nursery and floriculture industries, including 1) rising costs of other inputs and 2) reducing the effect of environmental regulations, like chemical runoff.

Identification of Plant Endophytes for Plant Protection Against Fungal Diseases, Pests and Environmental Stresses
Dr. Margaret Mmbaga
A wide range of endophytic bacteria and fungi that live inside plants without causing any symptoms are known to benefit their host plant in various ways including boosting plants defense system against pathogen, insect pests, environmental stresses and promoting plant growth. Fungal pathogens impose major constraints on agricultural production globally; despite the continued release of disease-resistant cultivars and chemical fungicides, fungal infections continue to cause crop yield losses and motivate the development of effective and durable disease management systems. These challenges are likely to worsen with climate change because of increased likelihood of drought and altered precipitation patterns. Novel, robust and naturally abundant microbial strains that colonize plants internally and enhance plant defense system against fungal pathogens are expected to be less vulnerable to external environmental fluctuations. Thus, endophytes can be an important source of biocompounds and provide valuable products for improving agricultural productivity with reduced agricultural chemicals, especially pesticides. There is need to identify such endophytes and utilize them to increase crop productivity. The main objective of this project is to identify endophytes that can be used to boost plant protection against diverse fungal pathogens. Specifically (1) identify endophytes that have utility as biological control agents against fungal pathogens and/or insect pests, and/or enhance plant tolerance to environmental stresses associated with climate change and (2) evaluate host range, plant colonization and plant growth promoting ability of the selected endophytes in horticultural crops including diverse vegetables and ornamental plants.

Improving Productivity and Soil-borne Disease Control in Nursery Crop Production
Dr. Fulya Baysal-Gurel
Nursery crops are produced on approximately 369,000 acres in the United States, with annual sale value of 6.6 billion dollars.  Woody ornamentals production in Tennessee takes place on 33,591 acres. Soil-borne diseases can be a major limitation to field  grown nursery production of woody ornamentals, particularly for propagation-field ground bed systems. In addition, based on  nursery inspections and disease samples we receive in the Plant Pathology Lab at the Tennessee State University Otis Floyd  Nursery Research Center, we have documented that soil-borne pathogens are the most economically important pathogens.  Fungal, oomycete, and bacterial pathogens, as well as viruses and plant parasitic nematodes, may all cause soil-borne  diseases. The National IPM Road Map has listed "Develop advanced management tactics for specific settings that prevent or  avoid pest attack" and efforts to "improve the efficiency of suppression tactics and demonstrate least-cost options and pest  management alternatives" as critical research needs. Soil-borne diseases are often difficult to control, and cannot be managed  solely through the use of crop rotations, improved disease-resistant varieties and chemical control. The addition of organic  matter such as cover crop green manure or good quality compost, soil solarization and application of biorational products are  also important management strategies for soil-borne disease management in sustainable field grown nursery production  systems. However, the effective use of these strategies in production of Tennessee field grown woody ornamentals appears to  be limited by a range of economic, social and technical factors.  The long-term goal of the proposed work is to improve production efficiency and reduce soil-borne disease pressure through  economic and effective applications of organic matter, soil solarization, chemical and biorational products on field grown  ornamental nurseries. Organic matter amendment, soil solarization, chemical and biorational products will be evaluated in field  grown nursery production systems and their effects on plants, soils, microbial communities, and soil-borne diseases will be  documented. Results from this research will be grower-oriented research-based recommendations, improved understanding of  the fundamental factors mediating improved crop growth and soil-borne disease suppression. 

Improving Profitability and Reducing Negative Environmental Impacts of Nursery Crops
Dr. Anthony Witcher
Nursery crop producers may encounter a wide range of factors (biotic and abiotic) that affect crop growth and quality including pests (insects, pathogens, weeds, etc.), mineral nutrition, and the environment (excessive rain, drought, wind, temperature extremes, etc.). Synthetic pesticides are widely used in nursery crop production, yet may pose an environmental threat (contaminate surface and ground water, non-target organism toxicity, etc.) and possibly exhibit reduced effectiveness due environmental conditions and cultural practices. As a result, balancing the environmental and financial impacts of crop production is an ongoing challenge for nursery crop producers.  The effectiveness and environmental fate of pesticides in alternative substrates used for nursery crop production will be evaluated to assure these practices are effective and safe. Additionally, alternative weed management techniques will be evaluated to determine suitability for use in nursery production systems. Results from this research will be used to identify new nursery crop production practices to reduce synthetic pesticide inputs and decrease ground and surface water contamination.
 

 

 

 

 

 






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