Submitted to: Crop Protection Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2001
Publication Date: 4/1/2001
Citation: Webster, T.M., Csinos, A.S., Johnson, A.W., Dowler, C.C., Sumner, D.R., Ferry R.L. 2001. Methyl bromide alternatives in a bell-pepper squash rotation. Crop Protection Journal. 20(7):605-614. Interpretive Summary: Methyl bromide is an effective soil fumigant used to control weeds, diseases, insects, and nematodes prior to planting many vegetable crops. However, methyl bromide has also been implicated in reducing the ozone layer, and thus its use is scheduled to be eliminated in 2005. Viable alternatives to methyl bromide for controlling multiple pests must be found dbefore it is eliminated. We evaluated the use of a plastic mulch and othe chemical treatments for controlling pests in a bell pepper-squash production system. Results showed that several alternatives were available for controlling most pests, though there was no one alternative with the broad spectrum pest control of methyl bromide. Our results indicated that none of the tested alternatives were as effective as methyl bromide for controlling the weed purple nutsedge.
Technical Abstract: Vegetable growers require viable alternatives against multiple pests to replacemethylbromide.Fieldstudiesevaluatedpotentialmethylbromide alternatives in a bell pepper-squash cropping sequence. Purple nutsedge emergence through the polyethylene mulch was suppressed by methyl bromide, methyliodide,andchisel-injected1,3-dichloropropenepluschloropicrin [1,3-D+C35 (chisel)]. However at the end of the season in 1999, only methylbromidesuppressedpurplenutsedgerelativetothenontreated control. Each soil-applied treatment resulted in nematode-susceptible pepper plants with lower root-gall indices than the nontreated control, while there were no differences among treatments with the nematode- resistant pepper cultivar. Total fungi isolated from soil was lower in all treated plots relative to the nontreated control, with the exception of methyl iodide. However methyl bromide was the only treatment that was consistently effective against Pythium spp. and Fusarium spp. Glyphosate applied between the first and second crop eliminated exposed weed foliage, possibly muting the effects of the second crop treatment on weed densities. Results of this study indicate that there are some potential methyl bromide alternatives available to growers for use in pest control, however there does not appear to be one broad spectrum pesticide that will replace methyl bromide. Also, an effective control for nutsedge species within the pepper-squash cropping system is still elusive.