CASE STUDY -- Methyl Bromide Alternative
Basamid for the Forest Nursery Industry
Basamid Granular, a chemical soil sterilant registered in the United States for use on forest tree seedling nurseries, is a technically feasible and cost-effective chemical alternative to methyl bromide. When applied to moist soils, the pesticide's active ingredient (tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) breaks down into methyl isothiocyanate, and has a broad spectrum of effectiveness against soilborne pests including nematodes, fungi and weeds (McElroy 1985, Pennington 1995).
Basamid offers advantages over existing soil sterilizing procedures or chemicals because it is relatively safe, economical, and easy to use. Basamid is a solid material, and, as such, the product stays inert until application. Basamid may be purchased in large quantities and stored easily, and overall, the product may decrease possible worker health risks compared to methyl bromide. In addition, environmental degradation is rapid with a half life of less than 24 hours under favorable conditions.
* provides economical, broad spectrum control of soilborne pests
* does not require tarp coverage
* non-persistent in the environment and is not considered to be an ozone depleting substance
* easily stored; 2 year shelf life
For best results, application directions on the product label should be followed and used as part of an Integrated Pest Management approach to controlling soil-borne pests. Important product label directions include:
- Application of Basamid requires precise timing and distribution in the soil. Basamid is typically applied in the fall, but fumigation can also be performed in the winter and spring. Post application tarping is not required.
- At all times, particular attention must be given to soil preparation, moisture, and temperature. The soil temperature should be above 50 F and should be moist and finely cultivated. Additionally, to prevent phytotoxicity, the soil should be aerated and a germination test should be performed prior to planting.
Basamid Performs in Commercial and Experimental Field Applications
In experimental and commercial applications, Basamid has been shown to be an effective preplant soil treatment. In tree seedling nurseries, Basamid can effectively control a number of soil-borne pests that affect tree seedlings including root-knot nematodes (Meloidogyne incognita), black root rot caused by Thielaviopsis basicola, and black shank (Phytophthora parasitica f. nicotianae) (Miner and Worsham 1990). In addition, by using Basamid, growers can achieve levels of tree seedling emergence and suppression of Fusarium oxysporium that are comparable to levels observed for seedlings treated with methyl bromide (Littke 1994). Two important Basamid field trial results are summarized below.
- Basamid was shown to be effective compared to methyl bromide/chloropicrin in controlling several varieties of soil-borne fungi and nematodes in a series of tests conducted in Kingston, Washington. Although both Basamid and methyl bromide/chloropicrin controlled Pythium and Fusarium, only Basamid was completely effective against Phytophtora, reducing populations to 2.3 propagules/gram of soil, compared to the control level of 243. In addition, Basamid was shown to significantly reduce seedling mortality, while increasing overall quality (McElroy 1985).
Alternatives to Methyl Bromide are Available for Forest Tree and Tobacco Nurseries
The production of tobacco and forest tree seedlings requires effective soil pest controls. Fortunately, the forest tree nursery industry has several alternatives to methyl bromide available to satisfy their soil pest control requirements. In fact, the use of methyl bromide in the production of forest tree seedlings has declined since 1990 as growers have shifted from field seedbed production to containers and specialized growing media, and alternative chemical and non-chemical controls (i.e., Basamid, metham-sodium, solarization and soil pasteurization, and bare fallow) as part of an Integrated Pest Management (IPM) approach. U.S.D.A and private bareroot forest nurseries in the United States have already significantly reduced or eliminated consumption of methyl bromide by shifting to metham-sodium, Basamid, Telone, chloropicrin, and a variety of cultural and non-chemical controls (Littke 1994, Bodmer 1994, Curtis 1994).
Cost of Basamid
A comparison of raw material costs and contract costs for Basamid and methyl bromide are provided below. As shown, the application costs for Basamid and methyl bromide/ chloropicrin differ based on the costs of the active ingredient and the labor involved in the application. Preparation for Basamid application includes preparing the plant bed, spreading and incorporating the chemical, sealing the soil by compaction and aerating it after treatment (BASF 1984, Nesmith 1995). Overall, Basamid is considered and economical and effective approach to controlling soil-borne pests affecting the production of forest tree seedlings in the United States.
Application Rate: 250 to 350 lb a.i./acre
Chemical Price: $2.90/lb
Calculated Material Cost: $725 to 1,015/acre
Approximate Contract Cost:$1,800 to $2,000
Methyl bromide/chloropicrin (67:33)
Application Rate: 375 lb a.i./acre
Chemical Price: $1.64/lb
Calculated Material Cost: $615/acre
Approximate Contract Cost: $1,800 to $2,000
Sources: N.W. Chemical 1995, Juzwik et al 1994, Pennington 1995, South 1995, Curtis 1994, Littke 1995, USDA 1989.
BASF. 1984 (March). Basamid Granular (APL/TD). BASF Aktiengesellschaft. Agricultural Research Station, D-6703 Limburgerhof, Federal Republic of Germany.
Bodmer. 1994 (August 22). Personal communication. Steve Bodmer, Montana State Forestry Department. Montana.
Curtis. 1994 (August 23). Personal communication. Ken Curtis, Washington State Forestry Department. Olympia, Washington.
Juzwik et al. 1994 (November 13-16). "Refinement of Basamid application for soil fumigation." J. Juzwik, USDA Forest Service; R. Allmaras, USDA Agricultural Research Service; D. Stenlund, University of Minnesota; S. Copeland, USDA Agricultural Research Service. 1994 International Conference on Methyl Bromide Alternatives and Emissions Reductions. Kissimmee, FL.
Littke. 1994 (November 13-16). "Meeting resource management goals through sustainable forest seedling production using alternative treatment strategies." Will Littke, Nursery Pathologist, Weyerhaeuser Research, Centralia, Washington. 1994 International Conference on Methyl Bromide Alternatives and Emissions Reductions. Kissimmee, FL.
McElroy. 1985 (November 15). Dr. F.D. McElroy. A newly registered sterilant shows strength in field tests. American Nurseryman.
Nesmith. 1995 (January 16). Personal communication. Dr. W.C. Nesmith, Professor of Plant Pathology, University of Kentucky. Kentucky.
N.W. Chemical Co. 1995 (April 18). Price quote: Basamid product cost. N.W. Chemical Co. Salem, Oregon.
Pennington. 1995 (January 17 and January 24). Personal communication. Willie Pennington, Basamid Product Manager, BASF Corp. Research Park, North Carolina.
South. 1995 (January 24). Personal communication. David South, Southern Forest Nursery Management Cooperative, Auburn University.
USDA. 1989 (August 14-18). Proceedings, Intermountain Forest Nursery Association: Bismarck, North Dakota. (General Technical Report RM-184). Rocky Mountain Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture. Fort Collins, Colorado.
More information on this alternative can be obtained by clicking here and visiting the manufacturers website.
Please note that this publication discusses specific proprietary products and pest control methods. Some of these alternatives are now commercially available, while others are in an advanced stage of development. In all cases, the information presented does not constitute a recommendation or an endorsement of these products or methods by the Environmental Protection Agency (EPA) or other involved parties. Neither should the absence of an item or pest control method necessarily be interpreted as EPA disapproval.
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