The strawberry industry in the Southeast region (SEUS; north of Florida) tends to consist of many limited acreage (5 acres average) growers who depend on this spring crop as a major source of their farm gate income. Costs of production can reach $13,000 or more per acre with gross returns of $15,000 to over $17,000 per acre if pests, particularly soilborne pathogens and weeds, are managed well . In the absence of effective management net returns are reduced by over $8000 per acre. Critical use nominations (CUN) to extend the use of methyl bromide as a soil fumigant were developed for the SEUS (AL, AK, GA, KY, LA, MS, NC, OH, SC, TN) through a participatory and industry-wide stakeholder process and the lack of adoption of alternatives was due to: 1) lack of confidence or data in about the alternatives, 2) costs of alternatives, 3) application difficulties due to such factors as hilly terrain, equipment requirements or weather patterns, 4) certain alternative fumigants cannot be used in environmentally sensitive areas, 5)current or emerging regulatory restrictions and 6) extensive pest pressure not sufficiently managed by alternatives. In addition, we are encountering many growers who are actively seeking non-fumigant based approaches to manage their crops and circumvent these (perceived or real) issues. Thus, it is critical that we continue to expand our research and extension efforts in fumigant and non-fumigant based systems. <P> Our long-term goal is to foster a strawberry industry that is competitive, sustainable, and conducive to SEUS farm viability. Such a vision encompasses short, mid- and long-term outcomes and is dependent on the diverse stakeholder objectives identified. Our objectives are i) to enable growers to transition to economically and technically viable non-ozone depleting fumigants; ii) to develop and/or implement other chemical-based tactics or non-chemical-based tactics extendable in the near term to effectively manage economically constraining soilborne pests and improve crop performance; iii) to enable growers to adapt to economically and technically viable biologically-based systems to complement fumigant and chemical inputs or to supplant them and iv) to effectively extend research-based information to stakeholders. Outputs will include training of field faculty, extension agents and other key consultants, frequent symposium and grower meeting presentations, extension publications and products, and scientific peer review publications that advance the science of strawberry production and soilborne pest management.
Non-Technical Summary: <BR>Over the years we have assembled an inter-disciplinary and inter-state response and vision team of key private and public sector stakeholders that seeks to implement chemical and biological-based alternatives to methyl bromide. Significant progress has been achieved in vegetable and strawberry production issues. This proposal focuses on advancing strawberry production systems by developing and extending readily adaptable fumigant and biologically-based approaches. Three strategic levels of research and extension are identified to address critical use nominations for the strawberry fruit industry in the Southeast USA: 1) Tactic substitution - addressing short term needs of growers who seek non-ozone depleting fumigant alternatives. The primary component includes fine-tuning the use of novel mulches and technologies to enhance efficacy and/or mitigate emerging regulatory issues; 2) Tactic Diversification - focuses on advancing current research efforts to incorporate novel and registered fungicides, nematicides and herbicides using pest-driven combinations for targeted and efficacious management of these soilborne pests; 3) Tactic Development - focuses on readily adaptable and biologically-based systems including use of best management systems with cover crops and compost, anaerobic soil disinfestation, mustard seed meal applications and biased soil profiles that favor beneficial microbial communities. Finally, we will focus on extending outcomes through multi-tactic mechanisms including participatory on-farm-research, web-based information, extension agent training, field days, presentations at most fruit and vegetable meetings in the SE and along the eastern seaboard, scientific presentations at professional meetings, peer reviewed publications, and writings in extension articles and industry driven newsletters. Combined efforts are expected to result in technically and economical feasible assessments and implementation of alternatives, exploration of viable diversification and development of integrated pest management tactics, and a region-wide advanced understanding of the biology, ecology and management of key soilborne pests. <P> Approach: <BR> Objective 1: We will continue to explore the use of existing or novel fumigants for efficacy against the major soilborne diseases and weeds of strawberries in combination with existing and emerging technologies such as types of mulch and application methods. We propose to incorporate reduced rate treatments in our field scale work through on farm research (OFR). Objective 2: We seek to determine the viability of using "smart" timing and judicial use of products to manage soilborne pests in strawberry production systems optimally applied to manage site-specific strawberry pests. We have been evaluating novel chemistry and technologies that we believe can play a major role in future non-fumigant dependent strawberry production systems. Likewise, we have documented strawberry crop phenology and know when strawberry plants have root growth spurts - providing an informed criteria of when optimal fungicide/pesticide timings can be applied. Therefore, we propose to design programs that combine our knowledge and experience about the biology of the pests, pesticide efficacy and use patterns, crop growth cycles and critical pathogen-free periods to develop non-fumigant approaches to manage targeted soil pests. Objective 3: There is a need to expand research and extension on the potential of anaerobic soil disinfestation as a tool to manage soilborne pests in SEUS strawberry production systems. There is also a need to further explore the efficacy of using mustard seed meal (MM) as a component of biologically-based systems to manage soilborne pests in strawberry production systems. We will use land with a long-term history of strawberry production in TN and NC on growers' fields and on research station land and implement various farming system practices that rely on cover crops, organic amendments and best management practices to enhance strawberry production. This work will be complemented with detailed soil and microbial community analysis. For the field work, we will collect weed and disease incidence data, whole plant samples, and our team or growers will collect yields, typically collected twice weekly. Treatments will be replicated in a RCDB and in some cases for OFR, growers will allow non-fumigate treatments. Local agents will be engaged to help collect data. Objective 4: Growers prefer production systems that offer improved economic performance (lower costs, higher yields, reduced inputs, and improved quality), as well as reduced risk. Therefore, we will evaluate economic performance of the proposed biological-based and chemical alternatives to MeBr by using partial budget and net economic value methods. The proposed analysis methods would allow our team to isolate, identify and value all economic gains and losses associated with each system and to assess system profitability. We will also adopt multiple methods to communicate research-based outcomes consistent with the history of our programs including agent training, symposiums, grower meetings/expos, extension publications and products and peer reviewed scientific publications.