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United States Department of Agriculture

Agricultural Research Service


Location: Crops Pathology and Genetics Research

2008 Annual Report

1a. Objectives (from AD-416)
1. Demonstrate alternatives to MB in key crop systems and regions dependent upon MB. This will be accomplished by conducting replicated, large-scale field trials that will compare standard treatments with MB to the best available alternatives. The alternatives will include substitute fumigants and supporting integrated pest management (IPM) practices. The trials will be conducted by multi-disciplinary teams in partnership with commercial growers at field locations that collectively represent the diversity of the commercial production systems. 2. Conduct comprehensive assessments of alternatives to MB in key crop systems and regions dependent upon MB. This will be accomplished by multi-disciplinary collection and analysis of biological, environmental, and economic data from the trials described above. 3. Identify key variables affecting the efficacy of MB alternatives and demonstrate management and predictive use of the variables to optimize performance of the alternatives. 4. Assess and demonstrate emissions reduction technologies and strategies for fumigant alternatives to MB. 5. Conduct multi-regional education programs that instruct growers, farm workers, and associated members of the agricultural community on optimized, IPM-supported use of MB alternatives.

1b. Approach (from AD-416)
The project will achieve its objectives by using a collaborative, inter-disciplinary approach and will include operational, assessment, and educational components. The operational component will involve horticulturists, soil and atmospheric chemists, plant pathologists, nematologists, weed specialists, engineers, economists, extension educators, and regulatory specialists working together with commercial growers, nurserymen, advisors, and other agricultural workers. The teams will demonstrate, assess, and optimize use of MB alternatives in commercial fields. The optimizations will focus on identifying and managing variables that maximize fumigant efficacy and minimize fumigant emissions. Where appropriate, integrated pest management practices will be demonstrated and evaluated for contributions to optimizing MB alternatives. The assessment component of the project will involve advanced analysis of economic, environmental, and social data obtained from the field trials. As information accumulates from activities in the operational and assessment components, it will be extended to end users in the educational component of the project. Educational outreach will be achieved via indoor and outdoor extension meetings, newsletters, educational websites, and peer-reviewed and popular publications. Teams involved in the operational, assessment, and educational components will be drawn from diverse public and private institutions, including, but not limited to: USDA-ARS (Davis, Parlier, Riverside, and Salinas locations, with possible contributions from Corvallis and Wenatchee); University of California, including UC Cooperative Extension; California Environmental Protection Agency; California Department of Food and Agriculture; commercial fumigant applicators and manufacturers; marketing and research boards for horticultural commodities; and producers.

3. Progress Report
A team of 11 scientist project leaders and 13 industry and regulatory stakeholders was convened and reviewed, revised, and approved 12 research and demonstration projects designed to facilitate effective transitions to integrated, economical methyl bromide (MB) alternatives for industries served by critical use exemptions for pre-plant soil fumigation with MB. The approved program includes projects for strawberry; almond and other stone fruits (peaches, plums, etc.); walnut; grape; cut flowers; sweet potato; perennial (fruit, nut, and woody ornamental) nurseries; forest nurseries; raspberry nurseries; and three projects focused reduction of fumigant emissions to the atmosphere. Each project conducted field trials and educational outreach designed to facilitate stable transitions to MB alternatives. The field trials were designed to test, optimize, integrate and demonstrate effective chemical and non-chemical alternatives to MB for each industry served. Strawberry trials were established in commercial fields near Watsonville, Salinas, Santa Maria, and Oxnard and focused on low rates alternative fumigants (i.e., chloropicrin [CP], 1,3-dichloropropene [1,3-D], and mixtures of 1,3-D and CP, and iodomethane:CP) and integrations with new plastic films that have potential to improve efficacy and reduce emissions of fumigation treatments. Strawberry trials also were established to foster development of non-fumigant-based strategies (i.e., use of non-fumigant chemicals, heat treatments, and biological control mixtures) for fruit production. Four almond and peach orchard replant trials were established near Arbuckle, Madera, and Parlier to test and demonstrate alternative fumigants (formulations of chloropicrin, 1,3-dichloropropene, and iodomethane); spot-fumigation treatments, which use novel GPS-controlled shank fumigation or spot drip applications to focus small amounts of fumigant on tree planting sites; and use of short-term crop rotations with and without supplementary fumigaiton.. The walnut, grape, cut flower, sweet potato, perennial nursery, and raspberry nursery projects each established field trials testing and demonstrating alternative fumigants and application methods to reduce fumigant emissions. Mustard rotation was tested as an alternative to fumigation for grape, and solarization was tested as an alternative and supplement to fumigation in raspberry and sweet potato nurseries. The projects conducted educational outreach at field demonstrations, extension meetings, and scientific conferences. The goals of the program are consistent with the vision and mission statements of National Program 308, Component 1, which are “replacement of methyl bromide with effective, economical and practical alternatives” and “(to) develop environmentally compatible and economically feasible alternatives to the use of methyl bromide as a soil and postharvest commodity treatment”.

4. Accomplishments
1. Demonstration and assessment of improved plastic mulches. Plastic mulches are used for conventional strawberry production for horticultural reasons and to improve retention of pre-plant fumigants in soil, thereby improving soilborne pest and pathogen control and reducing atmospheric emissions. Several new plastic mulches offer reduced permeability to fumigants and increased durability during field applications. Both have large impacts on overall mulch performance, but growers have had little experience with the new products and few data are available to document their performance. Three projects in the Crops Pathology and Genetics Research Unit in Davis, CA collaboratively tested and demonstrated the performance of the new plastic mulches under California coastal conditions. Several mulches with improved performance were identified and compared to conventional high density polyethylene. A new “totally impermeable film” was found that can be effectively glued as required for broadcast applications. The film is very durable under field conditions, maintaining extremely low permeability to fumigants following field application activities, which can damage some tarps. This accomplishment will lead to reduced atmospheric fumigant emissions and improved fumigant efficacy in the strawberry industry. This accomplishment relates to National Program 308, Component 1, Problem Statement 1B: Pest Management Systems to Optimize Efficacy of Pesticides and Reduce Harmful Emissions.

2. Development and demonstration of a GPS-controlled shank injection system for spot fumigation in orchards. Previous research indicated that pre-plant spot fumigation using hand-held probes at tree sites can prevent almond replant disease while using much less fumigant than conventional strip or broadcast fumigation with shank injection equipment. However, the probe treatments involved undesirable applicator risk and labor expense, and there was a need to develop a safe and economical spot fumigation system. In collaboration with the University of California Davis, a GPS-controlled shank injection system was developed by ARS scientists in the Crops Pathology and Genetics Research Unit in Davis, CA, which safely and economically fumigates tree sites using much less fumigant than conventional strip or broadcast treatments. The GPS-controlled system will dramatically reduce amounts of fumigant required to prevent almond and peach replant disease, thereby saving fumigant material cost and reducing fumigant emissions. This accomplishment relates to National Program 308, Component 1, Problem Statement 1B: Pest Management Systems to Optimize Efficacy of Pesticides and Reduce Harmful Emissions.

5. Significant Activities that Support Special Target Populations

Last Modified: 2/23/2016
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