ARS | Publication request: Evaluation of Various Chemical Treatments for Potential As Methyl Bromide Replacements for Disinfestation of Soilborne Pests in Polyethylene-Mulched Tomatoes

Submitted to: Proceedings Of Florida State Horticultural Society
Publication Acceptance Date: June 6, 2004
Publication Date: September 9, 2004
Citation: Gilreath, Jones, Motis, Santos, Noling, Rosskopf, E.N. 2004. Evaluation Of Various Chemical Treatments For Potential As Methyl Bromide Replacements For Disinfestation Of Soilborne Pests In Polyethylene-Mulched Tomatoes. Proceedings Of Florida State Horticultural Society Meeting. 116:151-158.

Interpretive Summary: Florida tomato growers rely on methyl bromide to eliminate soilborne pests including weeds, fungi, and nematodes. The phase out of methyl bromide requires the testing of alternative production approaches. Studies were conducted to evaluate alternative chemicals as part of the USDA, IR-4 Methyl bromide alternatives program. Chemical treatments included different rates, application methods, and combinations of iodomethane, metam sodium, sodium azide, furfural, 1, 3-dichloropropene, chloropicrin, and multiple herbicides. Tomatoes were produced following soil treatments. Incidences of nutsedge, Fusarium wilt, and root-knot, sting, and stunt nematodes were evaluated. No treatment controlled all pests; however, for each pest, one or more treatments performed as well as methyl bromide.

Technical Abstract: Tomato field trials were conducted using multiple rates, application methods, and combinations of iodomethane, metam sodium, 1, 3-dichloropropene, chloropicrin, and herbicides. Incidences of nutsedge, Fusarium wilt, and nematodes were evaluated. Application of methyl bromide (350 lb/A), metam sodium (75 gal/A, drip applied), iodomethane (150 lb/A, in bed), the combination of pebulate/fosthiazate pre-plant incorporated or drip applied/chloropicrin (4/4.5/200 lb/A) or the combination of trifluralin/1,3-dichloropropene//chloropicrin (.5 lb/26 gal/ 9 oz./A) resulted in the most significant reduction in nutsedge density at the Bradenton location. Pest populations at the Imokalee site were minimal. The incidence of Fusarium wilt at the Bradenton site was reduced by all treatments when compared to the untreated check. All treatments resulted in an increase in yield compared to the untreated check.