Source: UNIVERSITY OF TENNESSEE submitted to
ADVANCED DEVELOPMENT AND IMPLEMENTATION OF ANAEROBIC SOIL DISINFESTATION TECHNOLOGY AS AN ALTERNATIVE TO METHYL BROMIDE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
0222950
Grant No.
2010-51102-21707
Project No.
TEN02010-02801
Proposal No.
2010-02801
Multistate No.
(N/A)
Program Code
112.C
Project Start Date
Sep 1, 2010
Project End Date
Aug 31, 2014
Grant Year
2010
Project Director
Butler, D.
Recipient Organization
UNIVERSITY OF TENNESSEE
2621 MORGAN CIR
KNOXVILLE,TN 37996-4540
Performing Department
Plant Sciences
Non Technical Summary
Anaerobic soil disinfestation (ASD), a non-chemical alternative to soil fumigation with methyl bromide (MeBr), was developed in Japan and the Netherlands where it is used to control soilborne pathogens and nematodes in strawberries and vegetables. The ASD system can be utilized in urbanized areas where buffer restrictions would limit the applicability of alternative fumigants and, unlike many other biologically-based alternatives, has a broad-spectrum of activity, impacting most pests that are currently controlled by MeBr:chloropicrin combinations. This work will allow transfer of this promising technology to multiple cropping systems in many geographic locations and across differing soil types and environmental conditions in the United States. In a previously funded project, we confirmed the potential of ASD in Florida vegetable and coastal California strawberry production. To further that work, the goals of this project are threefold: (1) to build on previous efforts and further extend ASD for broad-spectrum control of soilborne pathogens, plant parasitic-nematodes, and weeds; (2) to gather additional data in tightly-controlled experiments to allow ASD to be effectively modeled and implemented across diverse local environmental conditions, production systems, and available inputs; and (3) to demonstrate the effectiveness of ASD in commercial-scale demonstration trials with production of a variety of economically important crops in Tennessee, Florida, and California to facilitate adoption of ASD by US growers who currently utilize MeBr under critical use and quarantine and preshipment allowances. To meet these goals, a team of multidisciplinary researchers and extension specialists from multiple institutions will work with grower advisory groups on project design, data interpretation, and grower implementation and outreach.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
50%
Developmental
50%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2122410116030%
2132410114030%
2122410112010%
2052410107010%
6012410301010%
1022410200010%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 212 - Pathogens and Nematodes Affecting Plants; 205 - Plant Management Systems; 213 - Weeds Affecting Plants; 601 - Economics of Agricultural Production and Farm Management;

Subject Of Investigation
2410 - Cross-commodity research--multiple crops;

Field Of Science
1070 - Ecology; 1160 - Pathology; 1120 - Nematology; 2000 - Chemistry; 3010 - Economics; 1140 - Weed science;
Goals / Objectives
The goals of this project are threefold: (1) to build on previous efforts and further develop Anaerobic Soil Disinfestation (ASD) for broad-spectrum control of soilborne pathogens, plant-parasitic-nematodes, and weeds; (2) to gather additional data in tightly-controlled experiments to allow ASD to be effectively modeled and implemented across diverse local environmental conditions, production systems, and available inputs; and (3) to demonstrate the effectiveness of ASD in research station and on-farm trials with production of a variety of economically important crops in Tennessee (TN), Florida (FL), and California (CA) in order to facilitate adoption of ASD by US growers, especially those who currently utilize either critical use exemption (CUE) or quarantine and preshipment (QPS) methyl bromide (MeBr). To meet these goals, we have seven objectives: (1) determine the relationships between cumulative anaerobicity/Eh under different temperature regimes and treatment length, and control of pathogens, nematodes, and weeds, (2) further improve the efficacy of ASD in CA and reduce site to site variability in disease suppression , (3) evaluate the effect of tarp permeability and color on ASD treatment in order to determine the most economical and efficacious tarp for ASD application, (4) evaluate flat applications of ASD for cut flower production, (5) establish on-farm trials to demonstrate and evaluate on-farm implementation of ASD, (6) compare the economic feasibility of optimized ASD with MeBr fumigation, and (7) transfer ASD technology through education and extension programs and evaluate project outcomes. We anticipate that ASD will be an effective and economic alternative to MeBr, with the potential to reduce fumigant use on a significant amount of farmland across the country. In practical terms ASD requires little modification to current practices, and unlike many biologically-based alternatives, we expect that ASD will effectively deal with multiple pest problems, as do chemical fumigants. We will work with interested growers to test and adapt the system themselves, and follow up on its performance. Using this adaptive management approach we estimate a timeline for significant commercial adoption of 4 to 6 years. Major environmental benefits can accrue from this project based on realized reductions in the use of MeBr and other chemical fumigants.
Project Methods
To develop survival curves versus cumulative anaerobicity for key pathogen, plant-parasitic nematode, and weed species, a series of studies will be established in pots in climate-controlled growth chambers. Survival of pathogens, nematodes, and weeds will be regressed against cumulative anaerobicity below 200mV (mV hr) to determine the level needed during Anaerobic Soil Disinfestation (ASD) treatment for pathogen, weed, and nematode control at differing temperature regimes. To address past variability in CA results, we will do further pot experiments (varying temperature and tarping time) and field/on-farm tests with different dates and tarping times to better identify relationships between time, temperatures, Eh, and disease and weed suppression. We propose to a) select fields with high disease pressure for on-farm studies, and b) modify the burial-retrieval methods by using alfalfa leaves infested with Verticillium dahliae as inoculum, rather than infested soil; and compare the methods. Field trials will also be established which will implement ASD treatment technology across several different tarp types and determine impacts on the effectiveness of ASD treatments. An on-farm trial will be established on a commercial tomato farm in Grainger County, TN for two years to evaluate large-scale, on-farm applications of ASD in comparison with grower standard methyl bromide (MeBr) fumigation. The most promising combination of treatments will be determined from small-scale greenhouse and research farm trials. Treatments will be implemented with two separate, replicated fumigated controls included for comparison: a MeBr standard and a metam sodium standard. An on-farm trial will be established in Zolfo Springs, FL to evaluate large-scale, on-farm implementation of ASD for production of ornamentals. Treatments will include a MeBr standard for comparison. The economic feasibility of ASD will be determined using data collected from field studies, a simulation model of actual grower operations under varying management practices (CA), and a marginal approach using partial budgeting techniques (TN, FL). The estimated net returns to each of the management options for each location and farm size will be calculated under a range of price scenarios to test for economic feasibility and to compare the profitability of the alternatives under various circumstances. Results will be disseminated using a combination of site visits, electronic team meetings, on-farm and Research and Education Center field days, grower meetings, on-farm demonstrations, distribution of newsletters and research briefs, maintenance of an interactive project website, workshops, and publications in scientific and popular literature including grower magazines. Education objectives will be met through incorporation of research site visits and results into undergraduate/graduate courses and the training of graduate and undergraduate students in ASD technology.

Progress 09/01/10 to 08/31/14

Outputs
Target Audience: Target audiences of scientific presentations included plant pathologists, weed scientists, soil scientists, horticulturalists, agricultural professionals and consultants, extension specialists, and policy makers from the USA and other countries. Target audiences of extension and outreach presentations included farmers, extension personnel, and agricultural consultants. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? In addition to numerous outreach activities to growers and agricultural professionals across all three states, as well as nationally and internationally (detailed below in section relating to result dissemination to communities of interest), the project supported the completion of one M.S.-level graduate student thesis (TN) and has given numerous undergraduate students (TN, CA, FL) and one post-doctoral researcher (FL) the opportunity to work in MeBr alternatives research and outreach. How have the results been disseminated to communities of interest? -Cooperators have published research in refereed scientific journals (e.g., Butler et al., 2012; Butler et al., 2014a, 2014b; Kokalis-Burelle et al., 2014; McCarty et al., 2014) in order to inform the scientific community of our work (see publications list for more detail), technical bulletins (Shrestha et al., 2014a, 2014b) and research reports with state grower groups (California Strawberry Commission, Florida Strawberry Growers). -Cooperators in all states presented at least 20 presentations at scientific and professional meetings during the course of the project which were directly related to project activities and research results. These meetings included the International Conference on Methyl Bromide Alternatives (MBAO), the Eighth International Symposium on Chemical and Non-Chemical Soil and Substrate Disinfestation (Torino, Italy), Annual Meeting of the American Phytopathology Society, Society for Nematologists Annual Meeting, Florida State Horticultural Society Annual Meeting, American Society for Horticultural Science Annual Meeting, Florida Tomato Institute Annual Meeting, Tennessee Horticultural Expo, International Biofumigation and Biopesticides Symposium, and American Society of Agronomy/Soil Science Society of America Annual Meeting (see publication lists for abstracts and proceedings). -Two webinars organized through eXtension/eOrganic were presented by project cooperators during the course of the project to present research results to a wide scientific and grower audience. Webinars are archived on YouTube and available at: https://www.youtube.com/watch?v=9TQmVQdaOVI and https://www.youtube.com/watch?v=_7phq_p2JQk -Outreach meetings and field days occurred in all states during the project, with at least 20 in CA, 4 in Tennessee, and 2 in Florida. Results were also presented at three meetings organized by the California Strawberry Commission. -ASD workshops (4), in which research outcomes and key practices of ASD technology were presented, were organized by Farm Fuel Inc. -A website summarizing ASD research projects, publications, technical bulletins, and more was developed for the project at the University of Tennessee. Available at http://vegetables.tennessee.edu/asd -Commercial implementation of ASD has been largely limited to California during the project period. By 2014, 29 California strawberry growers were using ASD commercially, with 49 fields (organic 71%, conventional 29%) totaling 431 acres. For the Tennessee and Florida teams, implementation activities were focused on increasing grower awareness of the potential for pathogen and weed control with the method through presentations and technical bulletins, and direct farmer visits and trials, in order to move toward more grower-directed trialing in each state and increasing on-farm commercial use. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In TN, a replicated field study was established to evaluate cover crop and off-farm C inputs for ASD treatment (Obj. 1). Results indicated combining cover crops and molasses may be an effective method of providing C sources for ASD treatment. No differences were observed in total tomato or bell pepper yields compared to the untreated control (UTC), but treatments differed in accumulated anaerobic conditions. There was an indication of ASD treatment activity against R. solani in some ASD treatments as well as control of monocot weeds in treatments which included a cover crop residue C source. Low overall pest pressure limited evaluation of treatment effects (see McCarty et al., 2014, HortScience 49:272-280). Repeated growth chamber experiments evaluating C source impacts on key soilborne pathogens and weeds under cool soil conditions (15 to 24°C) were completed. In trials with R. solani and S. sclerotiorum, ASD treatment did not effectively reduce pathogen inoculum survival, likely due to low C source amendment rates (~ 1 mg C/g soil). Growth chamber and field trials with S. rolfsii indicated increased parasitism of sclerotia by Trichoderma spp. in ASD-treated soils. See McCarty et al. (2012, M.S. thesis, University of Tennessee), Butler et al. (2014, Acta Horticulturae 1044:203-208), and Shrestha et al. (2014, Phytopathology 104:S3.108). Results from these studies were used to design additional studies evaluating C source rates and properties impact on ASD treatment effectiveness. In collaboration with FL and CA teams, a manuscript was published relating to soil nutrient dynamics in ASD-treated soils (See Butler et al., 2014 Plant & Soil 378:365-381). On-farm demonstration trials (Obj. 5) were completed on strawberry and tomato (see McCarty et al., 2014, M.S. thesis). A grower survey (Obj. 7) was conducted to evaluate grower receptiveness to non-chemical alternatives and perceived barriers to ASD use. Approximately half of surveyed growers indicated willingness to use ASD if shown as effective as fumigants. Growers indicated the greatest obstacles to implementation would be 1) availability of equipment for applying amendments, 2) local availability of appropriate soil amendments, 3) length of treatment period and 4) likelihood of consistent effectiveness. These results will be used to design further ASD research and outreach. Two extension publications were published (Obj. 7; see Shrestha et al., 2014a, UT Extension Bulletin SP 765-A and 2014b, UT Extension Bulletin SP 765-B), a website created (http://vegetables.tennessee.edu/asd) and extension events conducted (see outreach section of report). In CA, replicated field trials (Obj. 1, 2, 5) were conducted in 2010-11 under a range of soil types. ASD treatments with different carbon sources including rice bran (4.5 and 9 t/ac) and rice bran (8 t/ac) plus mustard seed cake (1 t/ac), were compared to UTC and PicChlor 60. ASD led to a 71 to 100% reduction in Verticillium dahliae in soils compared to UTC, under moderately high V. dahliae pressure. In a trial with moderately high disease pressure, marketable yield in ASD plots was 95% greater than UTC. In trials at Watsonville and Castroville, marketable yields from ASD plots were similar or numerically higher than PicChlor60 plots, and greater than UTC. Overall, ASD was effective in suppressing V. dahliae in soils (80 to 100%) and resulted in similar or greater marketable yield compared with fumigated controls. Economic analysis (Obj. 6) showed that net revenues above harvest and treatment cost of ASD was similar to the PicChlor fumigated control. In the 2011-12 season, field trials were conducted in Ventura (Fusarium spp. and Macrophomina spp. infested field), Watsonville (Pythium spp. and Cylindrocarpon spp. infested field), and Santa Maria (low disease pressure). Trials were established to compare ASD treatments (with rice bran 9 t/ac) with other non-fumigant alternatives (steam+solarization, steam+mustard seed meal 1.5 t/ac (MM), MM+solarization, ASD rice bran 7.5 t/ac + MM 1.5 t/ac (ASD+MM), and ASD+MM+solarization in Ventura; steam, MM, steam+MM, and ASD+MM in Watsonville; fish emulsion (FE), ASD+MM, and ASD+FE in Santa Maria), compared to UTC and PicChlor60 (Watsonville and Santa Maria) or chloropicrin (Ventura) controls. Marketable fruit yield was highest for PicChlor60, Steam+MM and ASD+MM, followed by ASD, then MM and steam which were higher than the UTC in Watsonville. In Santa Maria, ASD, ASD+FE, and ASD+MM plots had similar marketable yields as PicChlor60. At Watsonville, steam alone or with MM was as effective as PicChlor60 for weed control, but while ASD+MM suppressed weed densities over UTC, it was less effective than Steam and PicChlor60. A pot experiment comparing the effect of three temperature regimes on V. dahliae suppression in ASD showed that V. dahliae suppression is correlated with pH changes due to organic acid accumulation, with pH declines during ASD sensitive to temperature (Obj. 1, 2). We presented outcomes of the project at over 20 outreach events during 2012 and 2014 (Obj. 7). These promising results and outreach efforts resulted in a rapid increase of ASD acreage among CA growers; from 5 acres in 2011-12 to 430 acres in 2013-14. The number continues to increase in the 2014-15 season. See Shennan et al. (2013, Proc. Ann. Int. Conf. Methyl Bromide Alternatives Emission Reductions, 13-1 to 13-4) for more information. In FL, ASD trials were conducted over a two-year period comparing ASD, steam, and methyl bromide (Obj. 4, 5). Results were dependent upon the level of cut flower cultivar tolerance to root-knot nematode. For the most tolerant crops, ASD-treated plots produced the greatest number of marketable stems. For the most nematode susceptible crop, ASD and methyl bromide produced the largest plants, but root systems were severely galled and steam resulted in a greater level of nematode control. For highly susceptible crops, only a single crop could be harvested from ASD-treated plots, versus three plantings in the methyl bromide-treated plots (See Kokalis-Burelle, 2013, Society of Nematology Annual Meeting Abstracts and 2014, Outlooks on Pest Management, 25:287-293). In large-scale on-farm plots (Obj. 3, 5), a commercial producer of caladium and taro implemented ASD either under standard high density polyethylene, clear solarization plastic, or clear plastic followed by a second application of opaque polyethylene. These treatments were compared to methyl bromide for the commercial “standard” taro crop. ASD applied and the crop planted into the clear polyethylene was significantly stunted and resulted in a commercially unacceptable crop. The opaque polyethylene ASD treatment significantly increased the need for hand-weeding, while the double plastic application was found to produce an acceptable crop, but is not a practice that the grower would implement. In one series of experiments, a “standard” ASD approach (composted poultry litter, blackstrap molasses, transparent polyethylene film; see Butler et al., 2012, Crop Protection, 39:33-40) was implemented to determine if the clear plastic was required (Obj. 3). In one trial, five plastics were compared: “ASD-standard” clear, clear and white totally impermeable film, white virtually impermeable film, and white-on-black high density polyethylene. There were no significant differences in anaerobic activity, but differences between the average density of nutsedge, with the greatest numbers in the HDPE and the VIF. Nutsedge emergence was not correlated with cumulative anaerobic activity (Obj. 1). Based on these results, it is apparent that ASD could be implemented using TIF instead of solarization. It appears that one mechanism of nutsedge suppression could be physical, which is likely more important than cumulative anaerobic condition. See Rosskopf et al. (2014, HortScience annual meeting abstracts) for more information.

Publications

  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Butler, D.M., N. Kokalis-Burelle, J.P. Albano, T.G. McCollum, J. Muramoto, C. Shennan and E.N. Rosskopf. 2014. Anaerobic soil disinfestation (ASD) combined with soil solarization as a methyl bromide alternative: Vegetable crop performance and soil nutrient dynamics. Plant and Soil 378:365-381.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Butler, D.M., B.H. Ownley, M.E. Dee, S.E. Eichler Inwood, D.G. McCarty, U. Shrestha, N. Kokalis-Burelle and E.N. Rosskopf. 2014. Low carbon amendment rates during anaerobic soil disinfestation (ASD) at moderate soil temperatures do not decrease viability of Sclerotinia sclerotiorum sclerotia or Fusarium root rot of common bean. Acta Horticulturae 1044:203-208.
  • Type: Websites Status: Published Year Published: 2014 Citation: Butler, D.M. et al. Anaerobic soil disinfestation. Outreach website, http://vegetables.tennessee.edu/asd.htm
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Kokalis-Burelle, N., F.B. Iriarte, D.M. Butler, J.C. Hong and E.N. Rosskopf. 2014. Nematode management in Florida vegetable and ornamental production. Outlooks on Pest Management 25:287-293.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: McCarty, D.G., B.H. Ownley, A.L. Wszelaki, S.E. Eichler Inwood, C.E. Sams and D.M. Butler. 2014. Field evaluation of anaerobic soil disinfestation (ASD) carbon sources for tomato and bell pepper production in Tennessee. HortScience 49:272-280.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Rosskopf, E.N., D.M. Butler, N. Kokalis-Burelle and J.C. Hong. 2014. Using anaerobic soil disinfestation in organic vegetable production. Annual Conference of the American Society for Horticultural Science; Orlando, FL, 28-31 Jul 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Shennan, C., Muramoto, J., Baird, G., Fennimore, S., Mazzola, M., Lazarovits, G., Martin, F., Subbarao, K., Dara, S., 2014. Non-fumigant strategies for soilborne disease control in California strawberry production systems. California Strawberry Commission Annual Production Research Report 2012-2013. 153-171.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Shennan, C., Muramoto, J., Baird, G., Koike, S.T., Bolda, M.P., Mazzola, M. 2013. Optimizing anaerobic soil disinfestation for soilborne disease control. Proceedings of the Annual International Conference on Methyl Bromide Alternatives and Emission Reductions, 13-1  13-4. Nov. 3-5, 2013. San Diego, CA.
  • Type: Other Status: Published Year Published: 2014 Citation: Shrestha, U., A.L. Wszelaki and D.M. Butler. 2014. Introduction to anaerobic soil disinfestation as a fumigant alternative. University of Tennessee Extension Bulletin SP 765-A. The University of Tennessee Institute of Agriculture. Knoxville, TN.
  • Type: Other Status: Published Year Published: 2014 Citation: Shrestha, U., A.L. Wszelaki and D.M. Butler. 2014. Implementing anaerobic soil disinfestation in Tennessee. University of Tennessee Extension Bulletin SP 765-B. The University of Tennessee Institute of Agriculture. Knoxville, TN.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Shrestha, U., A. Bruce, B.H. Ownley and D.M. Butler. 2014. Effects of organic amendment C:N ratio on Fusarium oxysporum f. sp. lycopersici populations following anaerobic soil disinfestation. Phytopathology 104:S3.108.


Progress 09/01/12 to 08/31/13

Outputs
Target Audience: Target audiences of scientific presentations at the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions and Society for Nematology Meetings included plant pathologists, weed scientists, soil scientists, horticulturalists, agricultural professionals and consultants, extension specialists, and policy makers from the USA and other countries. Target audiences of extension and outreach presentations included farmers, extension personnel, and agricultural consultants. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? In addition to outreach activities to growers and agricultural professionals (detailed below), the project supported the completion of one M.S.-level graduate student thesis and has given numerous undergraduate students and one post-doctoral researcher the opportunity to work in MeBr alternatives research and outreach. How have the results been disseminated to communities of interest? In TN, outreach included a presentation to growers at the TN Horticulture Expo in January of 2013 and 3 presentations at a field day held at a university research site (Plateau Research and Education Center) in August of 2013. In CA, outreach was the focus during this grant period. Results from the past and on-going ASD trials were presented at multiple extension meetings and field days organized by the University of California (UC) Cooperative Extension (Salinas (11/13/12), Watsonville (2/5/13), Santa Maria (11/27/12 and 5/3/13) and Ventura (4/19/13)), the California Strawberry Commission (Watsonville (12/4/12 and 8/15/13)), UC Davis (Salinas (5/30/13)), UC Riverside (Riverside (3/19/13)), California Polytechnic State University (San Luis Obispo (12/7/12)) and Driscoll’s (Watsonville (5/15/13)). ASD workshops, in which research outcomes and key practices of ASD technology were presented, were held at the EcoFarm Conference (1/24/13), and at Watsonville (8/20/13) and Camarillo (8/29/13) organized by Farm Fuel Inc. In CA, each meeting, field day, or workshop on ASD had 15 to 100 participants. In the 2012-2013 season, some California berry growers started to implement ASD at commercial scale; ~20 growers used ASD in 32 fields (mostly organic) ranging from 0.5 to 20 acres in size, totaling 123 acres. Most growers who implemented rice bran-based ASD appeared to be satisfied with plant performance and yield level especially those possessing fields with high disease pressure, planning expansion of ASD treated fields. In FL, on-farm trials of ASD for cut flowers were used as demonstrations for other cut flower producers. Four school gardens and two Master Gardener gardens were established using ASD for demonstration purposes. What do you plan to do during the next reporting period to accomplish the goals? In TN and FL, pot studies will continue to evaluate C source rate and temperature impacts on key pathogens (Obj. 1). In FL, the final year of field trials under Obj. 3 and 4 will be completed. On-farm trials as part of Obj. 5 will continue in both states. Participants will continue work on economic analyses in all states and a grower survey in TN (Obj. 6) and in all states outreach activities will continue through a variety of methods and venues, including technical and scientific publications currently in preparation.

Impacts
What was accomplished under these goals? In TN, a number of growth chamber, research farm, and on-farm trials were completed as part of Obj. 1, and 5. One graduate student completed an M.S. thesis in December 2012, with a focus on ASD C source evaluation in TN (McCarty, 2012). In CA, grower outreach (Obj. 6) was the focus during this reporting period. Results from the past and on-going ASD trials were presented at multiple extension meetings and field days (see following section). In FL, four trials were conducted on the impact of different plastic types on weed control resulting from ASD. The first two plastic type trials were highly variable with regard to cumulative redox potential. In the first trial, there was no correlation between cumulative redox potential and weed control. However, in the second trial, there was a marginal negative correlation between the two. These trials were repeated and the trials have just been completed. Two on-farm, replicated grower-demonstration trials were conducted compared to flat fumigation and steam for cut flower production.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Butler, D.M., S.E. Eichler Inwood, D.G. McCarty, C.E. Sams, A.L. Wszelaki, M.E. Dee, B.H. Ownley, N. Kokalis-Burelle and E.N. Rosskopf. 2012. Optimizing anaerobic soil disinfestation for Tennessee. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions; pp. 13-1 to 13-3. Nov. 6-8, 2012. Orlando, FL.
  • Type: Theses/Dissertations Status: Published Year Published: 2012 Citation: McCarty, D.G. 2012. Evaluation of anaerobic soil disinfestation (ASD) as a fumigant alternative for warm-season vegetable production in Tennessee. M.S. Thesis, University of Tennessee.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Kokalis-Burelle, N., E.N. Rosskopf, J.C. Hong and D.M. Butler. 2013. Anaerobic soil disinfestation (ASD) and steam as alternatives for parasitic nematode control in Florida floriculture. Society of Nematologists 52nd Annual Meeting Abstracts; Knoxville, TN, 14-17 Jul 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: McCollum, T.G., E.N. Rosskopf, N. Kokalis-Burelle, D.M. Butler and M.G. Bausher. 2012. Impacts of alternative cropping systems on fruit quality: Opportunities for collaborative research. Proceedings of the Florida State Horticultural Society 125: 295-299.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Rosskopf, E.N., N. Kokalis-Burelle, J. Hong and D.M. Butler. 2012. Status of anaerobic soil disinfestation (ASD) development in Florida. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions; pp. 15-1 to 15-2. Nov. 6-8, 2012. Orlando, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Shennan, C., Muramoto, J., Baird, G., Fennimore, S., Koike, S.T., Bolda, M.P., Daugovish, O., Dara, S., Mazzola, M., Lazarovits, G. 2012. Non-fumigant strategies for soilborne disease control in California strawberry production systems. Proceedings for the Annual International Conference on Methyl Bromide Alternatives and Emission Reductions, 16-1  16-4, Nov. 6-8, 2012. Orlando, FL.
  • Type: Other Status: Published Year Published: 2012 Citation: Shennan, C., Muramoto, J., Koike, S.T., and Daugovish, O. 2012. Optimizing anaerobic soil disinfestation for non-fumigated strawberry production in California. California Strawberry Commission Annual Production Research Report 2010-2011. 111-123.


Progress 09/01/11 to 08/31/12

Outputs
OUTPUTS: In TN, the second year of a field study evaluating cover crop and off-farm C inputs (dried molasses, cereal rye cover crop residue with and without molasses, mustard/arugula cover crop residue with and without molasses, and mustard seed meal) for ASD treatment was completed in summer 2012. Impacts on soilborne pathogens, plant-parasitic nematodes, weeds, soil properties, and crop productivity were evaluated. Repeated growth chamber experiments evaluating C source impacts on soilborne pathogens and weeds under conditions (15 to 24C soil temperatures) present in the region in early spring soil treatment have been completed for Rhizoctonia solani and Sclerotinia sclerotiorum. The first of repeated growth chamber trials evaluating C source impacts on Sclerotium rolfsii, redroot pigweed, large crabgrass, and yellow nutsedge were completed during the reporting period. One on-farm demonstration was completed on strawberry and one replicated demonstration trial initiated on tomato (June) during the reporting period. In CA, field experiments were conducted in Ventura (Fusarium spp. and Macrophomina spp. infested field), Watsonville (Pythium spp. and Cylindrocarpon spp. infested field), and Santa Maria (low disease pressure). Randomized block experiments were established to compare ASD treatments (with rice bran 9 t/ac) with other non-fumigant alternatives (steam+solarization, steam+mustard seed meal 1.5 t/ac (MM), MM+solarization, ASD rice bran 7.5 t/ac + MM 1.5 t/ac (ASD+MM), and ASD+MM+solarization in Ventura; steam, MM, steam+MM, and ASD+MM in Watsonville; fish emulsion (FE), ASD+MM, and ASD+FE in Santa Maria), compared to untreated (UTC) and PicChlor60 (Watsonville and Santa Maria) or chloropicrin (Ventura) controls. Native soil pathogen populations were quantified before and after treatments; soil biological and chemical properties and marketable fruit yields were evaluated in Watsonville and Santa Maria. A 0.5 acre non-replicated ASD demonstration was established in the Spence USDA-ARS in Salinas in Oct. 2011. A pot experiment comparing the effect of three temperature regimes on V. dahliae suppression in ASD was also conducted. In FL, the first of repeated growth chamber studies were conducted to evaluate the response of F. oxysporum and M. incognita to varying rates of C amendments during ASD treatment (0, 1, 2, 3, 4, or 5 mg C/g soil) at varying soil temperatures. Three field trials were conducted in cooperation with a new organic grower on a site with high nutsedge populations. Two tests included six different types of polyethylene mulch (three clear and three opaque) and the third evaluated alternatives to poultry litter use during ASD treatment. Two additional field trials were conducted to compare ASD to a new experimental compound and to Telone C-35 for strawberry production. The first year of evaluation of ASD for cut flower production compared to MeBr and steam was completed. Soil samples were taken pre-treatment, at mid-season, and at harvest. Samples were evaluated for native fungal populations, total parasitic and non-parasitic nematodes, and total DNA was extracted for later use. PARTICIPANTS: PI/PD Dr. David Butler, Assistant Professor in The Department of Plant Sciences, University of Tennessee oversees implementation of the project and manages all Tennessee project activities. Dr. Butler supervises a technician and a graduate student working part-time on the project. Co-PI Dr. Carol Shennan, professor at the Department of Environmental Studies, University of California, Santa Cruz oversees and directly supervises the California aspects of the project. Co-PI Dr. Erin Rosskopf, plant pathologist, at USDA-ARS, Horticultural Laboratory, Fort Pierce, FL served as the Florida project coordinator. Dr. Rosskopf is involved in the design and establishment of field experiments and responsible for crop production programs. Co-PI Dr. Joji Muramoto, associate researcher at the Department of Environmental Studies University of California, Santa Cruz, coordinates the entire project, and is involved in designing and conducting field experiments in CA. Co-PI, Steve Koike, plant pathology farm advisor at the University of California Cooperative Extension-Salinas performs Verticillium dahliae viability tests for all CA experiments in his lab. Co-PI Dr. Karen Klonsky, University of California, Davis, is responsible for economic evaluations of ASD methods. Additional collaborators include Drs. Nancy Kokalis-Burelle, Greg McCollum, Joe Albano, Mark Mazzola, and Dong Wang, USDA-ARS; Drs. Mark Bolda, Oleg Daugovish, Steve Fennimore, and Maren Mochizuki, University of California; Drs. Annette Wszelaki, Margarita Velandia, Bonnie Ownley, and Carl Sams, University of Tennessee. Numerous private farmers (strawberry, vegetable, and cut flower) are involved with the project in Tennessee, California, and Florida. Collaborations have also been established with the Cumberland River Compact, an NGO working with farmers in the Cumberland River basin to improve environmental outcomes, the California Strawberry Commission, and the staff at eXtension/eOrganic. One M.S. student, D.G. McCarty is partially supported by the project at the University of Tennessee and is expected to complete his degree in December 2012. TARGET AUDIENCES: Target audiences of scientific presentations at the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, Weed Science Society, International Biofumigation and Biopesticides Symposium, and the American Society for Horticultural Science Meetings included plant pathologists, weed scientists, soil scientists, horticulturalists, agricultural professionals and consultants, extension specialists, and policy makers from the USA and other countries. Target audiences of extension and outreach presentations included farmers, extension personnel, and agricultural consultants. We estimate that our outreach activities directly contacted over 1000 individuals during the reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In TN, preliminary results suggest combining cover crops and molasses may be an effective method of providing C sources for ASD treatment while reducing costs. In research field trials, no significant differences were observed in accumulation of anaerobic conditions or total tomato or bell pepper yields in ASD treatments compared to the UTC. There was an indication of ASD treatment activity against R. solani in some ASD treatments (most notably mustard/arugula cover crop residue) as well as control of monocot weeds in treatments which included a cover crop residue C source. Low overall pest pressure likely limited the evaluation of treatment effects. In growth chamber trials with R. solani and S. sclerotiorum, ASD treatment did not effectively reduce pathogen inoculum survival, likely due to low C source amendment rates (~ 1 mg C/g soil). Growth chamber trials with S. rolfsii indicated increased parasitism of sclerotia by Trichoderma spp. in ASD-treated soils. In CA, marketable fruit yield was highest for Pichlor60, Steam+MM and ASD+MM, followed by ASD, then MM and steam which were higher than the UTC in Watsonville. In Santa Maria, ASD, ASD+FE, and ASD+MM plots had similar marketable fruit yields as PicChlor60, with FE slightly lower but still greater than UTC. At MBA, steam alone or with MM was as effective as PicChlor60 for weed control, but while ASD+MM suppressed weed densities over the UTC, it was less effective than Steam and PicChlor60. At Watsonville and Santa Maria sites, MM, ASD, ASD+MM, and Steam+MM treatments greatly increased soil inorganic N post treatment through Jan., but levels had decreased by May. PicChlor60 soil fumigation consistently suppressed total soil fungal densities, which were highest in the ASD and MM treatments and may indicate a more competitive soil environment. A pot experiment showed that V. dahliae suppression is correlated with pH changes due to organic acid accumulation, with pH declines during ASD sensitive to temperature. In FL, preliminary results suggest that at low soil temperature C source rates as high as 4 mg C/g soil may be needed to effectively control F. oxysporum. From the mulch trials, cumulative anaerobic activity was not impacted by plastic type; however weed control was significantly better in all plots with clear plastic during ASD. Effectiveness of ASD for cut flowers was dependent upon the level of cultivar tolerance to root-knot nematode (RKN). For three cut flower species with different growth habits, crop duration, and varying tolerance to RKN, ASD-treated plots produced the greatest number of marketable stems for two species. For the most nematode-susceptible crop, snapdragon, ASD and MeBr treatments produced the largest plants, but also the most severely galled root systems. For this species, steam treatments resulted in more effective nematode control. Control of introduced inoculum of the broad-host range pathogen Macrophomina phaseolina with ASD was significantly better than the other treatments. Optimizing nitrogen management for strawberry in FL will be critical for successful adoption of ASD.

Publications

  • Shennan, C., J. Muramoto, G. Baird, O. Daugovish, S. Koike, and M. Bolda. 2011. Anaerobic Soil Disinfestation: California. In Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions; pp. 44-1 to 44-4.
  • Butler, D.M., N. Kokalis-Burelle, J. Muramoto, C. Shennan, T.G. McCollum, and E.N. Rosskopf. 2012. Impact of anaerobic soil disinfestation combined with soil solarization on plant-parasitic nematodes and introduced inoculum of soilborne plant pathogens in raised-bed vegetable production. Crop Protection 39:33-40.
  • Klonsky, K., C. Shennan, and J. Muramoto. 2011. Economic performance of non-fumigant strawberry production systems. In Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. Pp. 48-1 to 48-2.
  • Mazzola, M., Muramoto, J. and Shennan C. 2012. Transformation of soil microbial community structure in response to anaerobic soil disinfestation for soil-borne disease control in strawberry. Phytopathology 102: (in press)
  • McCarty, D.G., B.H. Ownley, A.L. Wszelaki, C.E. Sams, and D.M. Butler. 2012. Evaluation of anaerobic soil disinfestation (ASD) for warm-season vegetable production in Tennessee. Annual Conference of the American Society for Horticultural Science; Miami, FL, 31 Jul-3 Aug 2012.
  • Rosskopf, E.N., N. Kokalis-Burelle, and D. M. Butler. 2012. Non-fumigant weed control alternatives to methyl bromide. Weed Science Society of America Annual Meeting Abstracts; Waikoloa, HI, 6-9 Feb 2012. Rosskopf, E.N., N. Kokalis-Burelle, and D.M. Butler. 2011. Non-fumigant weed and disease management systems for vegetable and floriculture production. Proceedings of the 4th International Biofumigation and Biopesticides Symposium; Saskatoon, SK, Canada, 18-21 Oct 2011.
  • Rosskopf, E.N., N. Kokalis-Burelle, D.M. Butler, J. Muramoto, C. Shennan, J. Noling, Z. He, B. Booker, F. Sances, and T. Campbell. 2011. Field evaluation of broad-spectrum non-fumigant pest control approaches for Florida strawberry production. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions; pp. 45-1 to 45-3.
  • Shennan, C., J. Muramoto, S. Koike, M. Bolda, O. Daugovish, M. Mochizuki, K. Klonsky, E.N. Rosskopf, N. Kokalis-Burelle, and D.M. Butler. 2011. Anaerobic Soil Disinfestation for Suppressing Verticillium dahliae in Strawberry Production in California. In American Society of Horticultural Science, Annual Meeting Abstracts; HI, 26 Sep 2011.


Progress 09/01/10 to 08/31/11

Outputs
OUTPUTS: In TN, a field study was established in March 2011 to evaluate anaerobic soil disinfestation (ASD) methods for warm-season vegetable production (tomato, bell pepper) in a randomized complete block with four replicates. Impacts on soilborne pathogens, plant-parasitic nematodes, weeds, soil properties, and crop productivity were evaluated. Greenhouse/growth chamber experiments evaluating carbon source impacts on soilborne plant pathogens and weeds under expected soil and climatic conditions present in the region have been completed for several pathogens and data analysis is ongoing. An on-farm experimental site has been established, with cover crops planted to prepare the site for ASD treatment in 2012. One M.S. student is currently working on aspects of the TN projects. To optimize ASD for California strawberries, field experiments were conducted in Ventura, Watsonville and Castroville, CA in the 2010-11 season. Soil types in trials ranged from sandy loam to silty clay loam. Randomized block experiments with four replicates were established to compare ASD treatments with different carbon sources including rice bran (4.5 tons/acre and 9 tons/acre) and rice bran (8 tons/acre) plus mustard seed cake (1 ton/acre), compared to untreated checks (UTC) and PicChlor 60 fumigation controls (except at the Ventura site). Native Verticillium dahliae populations in soil (0 to 6 in depth) were quantified before and after treatments and during the harvest period; soil properties and marketable fruit yields were evaluated. Research trials in FL were conducted in strawberry in fall 2010 and repeated beginning in fall 2011. Three vegetable trials and one cut flower trial were established for fall 2011. In the vegetable trials, randomized complete block experiments were established to compare ASD treatments using six different types of plastic mulch. The objective of the experiment was to determine if opaque totally impermeable film (TIF) could be substituted for standard solarization film in order to eliminate the need for two plastic laying events, ie. replacing the solarization film after the ASD treatment. Data from these experiments are being compiled and analyzed. Based on nutsedge data, it does not appear that the TIF film provided adequate control in the absence of solarization. Utilization of ASD for a crop not produced in a raised-bed is being tested for production of cut flowers. Outreach during the reporting period included an extension presentation on ASD methods given to approximately 25 farmers and extension personnel at the TN Horticultural Expo in January 2011. Collaborators from all states presented an on-line webinar in March 2011 on ASD research results and methods for researchers, farmers, and extension personnel that has been viewed by nearly 800 individuals to date. A field day was held at the Tennessee research site in late April 2011, where >100 farmers, extension agents, and industry personnel attended a presentation on ASD methods. Crop consultants (~25) attended a seminar on ASD and other alternatives to soil fumigants at the TN Agricultural Production Association annual meeting. PARTICIPANTS: PI/PD Dr. David Butler, Assistant Professor in The Department of Plant Sciences, University of Tennessee oversees implementation of the entire project and manages all Tennessee project activities. Dr. Butler supervises a technician, a graduate student, and two undergraduate students working on the project. Co-PI Dr. Carol Shennan, professor at the Department of Environmental Studies, University of California, Santa Cruz oversees and directly supervises the California aspects of the project. Co-PI Dr. Erin Rosskopf, plant pathologist, at USDA-ARS, Horticultural Laboratory, Fort Pierce, FL served as the Florida project coordinator. Dr. Rosskopf is involved in the design and establishment of field experiments and responsible for crop production including design and implementation of irrigation and fertilization programs. Co-PI Dr. Joji Muramoto, associate researcher at the Department of Environmental Studies University of California, Santa Cruz, coordinates the entire project, and is involved in designing and conducting field experiments in CA. Co-PI, Steve Koike, plant pathology farm advisor at the University of California Cooperative Extension-Salinas performs Verticillium dahliae viability tests for all CA experiments in his lab. Co-PI Dr. Karen Klonsky, University of California, Davis, is responsible for economic evaluations of ASD methods. Additional collaborators include Drs. Nancy Kokalis-Burelle, Greg McCollum, Joe Albano, and Dong Wang, USDA-ARS; Drs. Mark Bolda, Oleg Daugovish, and Maren Mochizuki, University of California; Drs. Annette Wszelaki, Margarita Velandia, Bonnie Ownley, and Carl Sams, University of Tennessee. Numerous private farmers (strawberry, vegetable, and cut flower) are involved with the project in Tennessee, California, and Florida. Collaborations have also been established with the Cumberland River Compact, an NGO working with farmers in the Cumberland River basin to improve environmental outcomes, the California Strawberry Commission, and the staff at eXtension/eOrganic. One M.S. student, D.G. McCarty is partially supported by the project at the University of Tennessee. Mr. McCarty is responsible for all field projects in Tennessee as well as growth chamber assays on ASD effectiveness against inoculum of Sclerotium rolfsii and weed populations. TARGET AUDIENCES: Target audiences of scientific presentations at the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions and the American Society of Agronomy Meetings included plant pathologists, weed scientists, soil scientists, horticulturalists, fumigation industry representatives, and policy makers from the USA and other countries. Target audiences of extension and outreach presentations included farmers, extension personnel, and agricultural consultants. We estimate that our outreach activities directly contacted over 1,000 individuals during the reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
In Tennessee, while data analysis is in progress, preliminary results suggest that combining cover crops and molasses may be an effective method of providing carbon sources for ASD treatment. Outreach in Tennessee has already encouraged 3 strawberry producers and 1 fresh market tomato producer to begin evaluating ASD methods on their farms on a trial basis in comparison to their standard fumigation practices. In California, accumulation of anaerobic soil conditions near or exceeding a threshold established by earlier pot experiments was observed for most ASD plots across trials. ASD led to a 71 to 100% reduction in Verticillium dahliae in soils compared to the UTC in Salinas, Ventura and Castroville, under moderately high V. dahliae pressure. In the summer-planted Ventura trial with moderately high disease pressure, marketable yield in ASD plots was 95% greater than UTC (P<0.0001). In trials at Watsonville and Castroville, marketable yields from ASD plots were similar or numerically higher than PicChlor60 control plots, and significantly greater than UTC (P=0.05). Overall, ASD was very effective in consistently suppressing V. dahliae in soils (80 to 100%) and resulted in similar or greater marketable fruit yield compared with fumigated controls. Economic analysis of the Castroville and Watsonville trials showed that net revenues above harvest and treatment cost of ASD was similar to the PicChlor fumigated control. Results from the Watsonville trial triggered several local strawberry, raspberry and greenhouse herb growers to try ASD on their farms in the 2011-12 season. We are working closely with them for successful ASD adoption. In the Florida strawberry trial, the most significant finding to date is that the ASD approach provides control of introduced inoculum of Macrophomina phaseolina that is equivalent or better than the fumigant control. In Florida, the weed control efficacy of the combination of ASD and solarization has been significant enough to lead to additional on-farm research trials for vegetables at the request of local organic producers and one conventional producer. Two school gardens as well as several Master Gardener gardens have also been established with this technique to facilitate project outreach. We have not yet conducted an economic analysis utilizing the Florida or Tennessee results.

Publications

  • Shennan, C., Butler, D.M., Muramoto, J., Koike, S.T., Bolda, M., Daugovish, O., Mochizuki, M., Rosskopf, E.N., and Kokalis-Burelle, N., 2011. A Novel Strategy for Soil-borne Disease Management: Anaerobic Soil Disinfestation (ASD). eOrganic Webinar. 30 March, 2011. Available online at http://youtu.be/9TQmVQdaOVI
  • Shennan, C, Muramoto, J., Koike, S.T, Bolda, M., Daugovish, O., Mochizuki, M., Rosskopf, E.N., Kokalis-Burelle, N., and Butler, D.M. 2010. Optimizing Anaerobic Soil Disinfestation for Strawberry Production in California. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. 23-1- 23-4
  • Rosskopf, E.N., Kokalis-Burelle, N., Butler, D.M., Muramoto, J., and Shennan, C. 2010 Development of anaerobic Soil disinfestation for Florida vegetable and flower production. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. 84-1-84-2
  • Butler, D.M., Rosskopf, E.N., Kokalis-Burelle, N., Albano, J. P., Muramoto, J., and Shennan, C., 2010. Cover crop as carbon sources for anaerobic soil disinfestation in a vegetable production system. The American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America annual meeting. Abstracts; Long Beach, CA, 31 Oct.-4 Nov. 2010