Methyl bromide is a highly effective broad-spectrum fumigant used extensively to control a wide variety of soilborne pests in U.S. agriculture. Under the Montreal Protocol of 1991, MeBr was defined as a chemical that contributes to the depletion of the stratospheric ozone layer, and the amount of MeBr produced and imported in the United States was incrementally reduced until the phaseout took effect 1 Jan. 2005, except for emergency and critical use exemptions (Osteen, 2003; U.S. Department of Agriculture (USDA), 2008a; U.S. Environmental Protection Agency, 2008). Recent data suggest that the international restrictions on human-generated sources of bromine slowed down growth in stratospheric ozone-depleting brominated substances (Dorf et al., 2006), and these substances have decreased in the troposphere (Montzka et al., 2003).
An economic analysis conducted by the U.S. Department of Agriculture indicates that the phaseout of MeBr as a preplant soil fumigant may have substantial impact on many commodities because no known single alternative fumigant, chemical, or other technology exists that can readily substitute for MeBr in efficacy, cost, ease of use, availability, worker safety, and environmental safety below the ozone layer (Osteen, 2003; USDA, 2008a). Among possible alternatives are host plant resistance, biological control, cultural practices, and alternative chemicals, either alone or in combination (Gullino et al., 2003; Manning and Fennimore, 2001; Martin, 2003; Rieger et al., 2001; Ristaino and Thomas, 1997; Rosskopf et al., 2005; Schneider et al., 2003). A few products that have a long history of use include 1,3-dichloropropene, metam sodium, chloropicrin, and combinations of these [e.g., 61.1% 1,3-dichloropropene + 34.7% chloropicrin (Telone-C35™; Dow AgroSciences, Indianapolis)] (Duniway, 2002; Martin, 2003; Schneider et al., 2003). The availability of alternative control measures is generally limited because of variations in the target pests, soil types, climates, and state and local regulations.
Fresh market tomatoes were planted on 124,400 acres in the United States in 2007, with a gross production value of almost $1300 million. Southeastern states (Georgia, North Carolina, South Carolina, Tennessee, and Virginia) accounted for about 17% of the total U.S. tomato production (USDA, 2008b). Tomatoes also accounted for 25% of the United States preplant use of MeBr in 1997. Therefore, tomato growers are one of the groups impacted by the new MeBr regulations (Osteen, 2003; Santos et al., 2006).
A series of MeBr alternative trials conducted at the Mountain Horticultural Crops Research Station in Fletcher, NC, documented the efficacy of alternative fumigants in an annual plasticulture tomato production system (Louws et al., 2004, 2006; Welker et al., 2005a, 2005b, 2007). Fletcher is in western North Carolina (lat. 35°25′36.5″N, long. 82°33′25.53″W) and is typical of the Appalachian tomato production region, which includes northern Georgia, western South Carolina, eastern Tennessee, and southwestern Virginia. Documented soilborne pathogens at this site include verticillium wilt (Verticillium dahliae race 1 and race 2), pith necrosis (Pseudomonas corrugata), Pythium spp., and damping off and root rot (Rhizoctonia spp.). Verticillium dahliae race 2 is the most common and most serious soilborne pathogen within this production region and at the Fletcher research station. Weed species primarily included summer annual weeds, such as palmer amaranth (Amaranthus palmeri), common purslane (Portulaca oleracea), goosegrass (Eleusine indica), florida pusley (Richardia scabra), carpetweed (Mollugo verticillata), prickly sida (Sida spinosa), and crowfootgrass (Dactyloctenium aegyptium). The tomato cultivar Mountain Fresh was planted in all trials except one trial in 2005 and one trial in 2006, when cultivars Amelia and Biltmore were planted, respectively.
These trials were part of a broader study also looking at economically feasible alternatives to MeBr in production of strawberry (Fragaria ×ananassa) in the southeastern United States (Sydorovych et al., 2006). The summary of the products, application rates, and years of tomato trials are presented in Table 1.
Alternative soil treatments, application rates, and years when the soil treatments were evaluated in tomato production systems at the Fletcher, NC, experimental site from 2001 to 2007.
The objective of this report was to analyze the economic feasibility of the chemical alternatives to MeBr in the plasticulture production of tomatoes in the mountain region of North Carolina. First, we estimated the costs and returns associated with growing, harvesting, and marketing tomatoes in systems including preplant fumigation with MeBr in a plasticulture production system. Second, we evaluated the economic feasibility of the alternatives to MeBr using a partial budget methodology.
Dorf, M., Butler, J.H., Butz, A., Camy-Peyret, C., Chipperfield, M.P., Kritten, L., Montzka, S.A., Simmes, B., Weidner, F. & Pfeilsticker, K. 2006 Long-term observations of stratospheric bromine reveal slow down in growth Geophys. Res. Lett. 33 L24803
Gullino, M.L., Camponogara, A., Gasparrini, G., Rizzo, V., Clini, C. & Garibaldi, A. 2003 Replacing methyl bromide for soil disinfestation: The Italian experience and implications for other countries Plant Dis. 87 1012 1021
Konsler, T.R. & Gardner, R.G. 1990 Commercial production of staked tomatoes in North Carolina North Carolina Coop. Ext. Serv. Publ. AG-60
Louws, F.J., Ferguson, L.M., Ivors, K., Driver, J., Jennings, K., Milks, D., Shoemaker, P.B. & Monks, D.W. 2004 Efficacy of methyl bromide alternatives for verticillium and weed management in tomatoes 8 May 2008 <http://mbao.org/2004/Proceedings04/043%20Louws%20tomato%202004.pdf>.
Louws, F.J., Welker, R.M., Driver, J.G., Jennings, K. & Monks, D.W. 2006 Efficacy of methyl bromide alternatives for weed and verticillium management in tomatoes 8 May 2008 <http://mbao.org/2006/06Proceedings/061Louwsetalweed2006.pdf>.
Manning, G.R. & Fennimore, S.A. 2001 Evaluation of low-rate herbicides to supplement methyl bromide alternative fumigants to control weeds in strawberry HortTechnology 11 603 609
Martin, F.N. 2003 Development of alternative strategies for management of soil borne pathogens currently controlled with methyl bromide Annu. Rev. Phytopathol. 41 325 350
Montzka, S.A., Butler, J.H., Hall, B.D., Mondeel, D.J. & Elkins, J.W. 2003 A decline in tropospheric organic bromine Geophys. Res. Lett. 30 1826
Rieger, M., Krewer, G. & Lewis, P. 2001 Solarization and chemical alternatives to methyl bromide for preplant soil treatment of strawberries HortTechnology 11 258 264
Roberts, W.S. & Swinton, S.M. 1996 Economic methods for comparing alternative crop production systems: A review of the literature Amer. J. Alternative Agr. 11 10 17
Rosskopf, E.N., Chellemi, D.O., Kokalis-Burelle, N. & Church, G.T. 2005 Alternatives to methyl bromide: A Florida perspective 8 May 2008 <http://www.apsnet.org/online/feature/methylbromide/>.
Sanders, D.C. 2001 Fresh market tomato production piedmont and coastal plain of North Carolina North Carolina Coop. Ext. Serv. Publ. HIL-28-A
Santos, B.M., Gilreath, J.P., Motis, T.N., Noling, J.W., Jones, J.P. & Norton, J.A. 2006 Comparing methyl bromide alternatives for soilborne disease, nematode and weed management in fresh market tomato Crop Prot. 25 690 695
Schneider, S.M., Rosskopf, E.N., Leesch, J.G., Chellemi, D.O., Bull, C.T. & Mazzola, M. 2003 USDA-ARS research on alternatives to methyl bromide: Pre-plant and post-harvest Pest Mgt. Sci. 59 814 826
Sydorovych, O., Safley, C.D., Ferguson, L.M., Poling, E.B., Fernandez, G.E., Brannen, F.M., Monks, D.W. & Louws, F.J. 2006 Economic evaluation of methyl bromide alternatives for the production of strawberries in the southeastern United States HortTechnology 16 118 128
U.S. Department of Agriculture 2008a Methyl bromide Agricultural Research Service 23 Jan. 2008 <http://www.ars.usda.gov/Research/docs.htm?docid=10408>.
Warmann, G.W. 1995 Economics of liming Kansas cropland: Owner-operator and landlord-tenant considerations Kansas State Univ. Ext. Publ. MF-2137
Welker, R.M., Driver, J.G. & Louws, F.J. 2005a Efficacy of fall and spring applied methyl bromide alternatives in tomatoes 8 May 2008 <http://mbao.org/2005/05Proceedings/015WELKERTomatoMBAO2005.pdf>.
Welker, R.M., Driver, J.G. & Louws, F.J. 2005b Methyl bromide alternatives training for extension agents and growers 8 May 2008 <http://mbao.org/2005/05Proceedings/011WELKERtrianingMBAO2005.pdf>.
Welker, R.M., Driver, J.G., Smith, J.P., Brannen, P.M., Schiemann, C.A. & Louws, F.J. 2007 On-farm research to implement MB alternatives: An area wide initiative 8 May 2008 <http://mbao.org/2007/Proceedings/022LOUWSareaWideMBAO07.pdf>.
Wossink, G.A.A. & Osmond, D.L. 2002 Farm economics to support the design and selection of cost-effective BMPs: Nitrogen control in the Neuse River Basin, North Carolina J. Soil Water Conservation 57 213 220