Fumigant Alternatives for Methyl Bromide Prior to Turfgrass Establishment¹

Abstract

Potassium azide (PA) (112 kg/ha), oxadiazon + 1,3-dichloropropene (1,3-D) (168 kg/ha + 140 L/ha), dazomet (392 kg/ha), dazomet + chloropicrin (392 + 168 kg/ha), dazomet + 1,3-D (392 kg/ha + 140 L/ha), iodomethane (IM) (336 kg/ha), metam-sodium (MS) (748 L/ha), MS + chloropicrin (748 L/ha + 168 kg/ha), and MS + 1,3-D (748 + 140 L/ha) were evaluated at Jay and Arcadia, FL, in 1998 and 1999 as alternatives to methyl bromide (MeBr) fumigation for the management of common turfgrass weeds. Potassium azide was as effective as MeBr in controlling ‘Coastal’ bermudagrass, yellow and purple nutsedges, alexandergrass, broadleaf signalgrass, tall and sharppod morningglories, and various winter annual broadleaf weeds, but it failed to provide acceptable control of redroot pigweed. 1,3-Dichloropropene + oxadiazon did not control yellow nutsedge, purple nutsedge, or Coastal bermudagrass. Similarly, this combination treatment failed to control carpetweed but did provide 83% control of the winter annual weed species, 71% control of alexandergrass and broadleaf signalgrass, and ≥ 80% control of tall morningglory, sharppod morningglory, and redroot pigweed. Dazomet + combination treatments provided control of Coastal bermudagrass at Jay; however, control of common bermudagrass, alexandergrass, and broadleaf signalgrass was not acceptable at Arcadia. Sedge species control with dazomet + combinations was poor (< 63%) at both sites. Iodomethane, a treatment not yet registered by the U.S. Environmental Protection Agency (EPA), controlled weedy grass species, sedge species, and broadleaf weeds present at the two locations under different environmental conditions. Metam-sodium alone and MS + chloropicrin, tarped and untarped, and MS + 1,3-D provided acceptable weed control; however, MS + chloropicrin covered with a plastic tarp for 48 h was the best MS treatment. Metam-sodium + chloropicrin, with plastic tarp, controlled weedy grass and broadleaf species equal to MeBr; however, unacceptable sedge species control at Jay and Arcadia was 56 and 79%, respectively. Metam-sodium applied alone failed to control redroot pigweed; however, MS + combinations provided control. These studies confirm that no EPA-registered fumigant alternative to MeBr, applied alone or in combination for preplant turf soil fumigation, exists. Consequently, until such time that an effective alternative is identified, turf managers will be forced to forego fumigation, or they will have to choose a less-effective alternative and accept the consequences of contamination.

Methyl Iodide

“…The same authors also noted that MeI produced similar control of the pest to a combination of 1,3-dichloropropene with 17% chloropicrin (essentially the commercial product, Telone C-17). Unruh et al (2002) found that MeI controlled weedy grass species, sedge species, and broadleaf weeds present at two locations under differing environmental conditions. However, Webster et al (2001) noted that while MeI was effective in controlling purple nutsedge early in the growing season of a bell pepper-squash cropping sequence, by the end of the growing season, the MeI offered no advantage over a control.…”

Weed Community Composition in Tree Fruit Nurseries Treated with Methyl Bromide and Alternative Fumigants

“…(Gilreath et al, 2005;Chase et al, 2006), Ipomoea sp., and several other annual weeds such as Amaranthus retroflexus L. (Unruh et al, 2002), but was weak against Cynodon dactylon L. Pers. and Mollugo verticillata L. (Unruh et al, 2002). A commercial formulation of 1,3-D (61%) + chloropicrin (33%) also has been tested as a MeBr replacement.…”

“…Iodomethane controlled several grass weed species, sedges, and broadleaf weeds in turf (Unruh et al, 2002). Zhang et al (1997) reported good control of A. retroflexus with iodomethane and found that it was more potent than MeBr on Lolium multiflorum Lam., Abutilon theophrasti Medik., Chenopodium album L., P. oleracea, Brassica kaber (DC.)…”

Evaluation of EPTC as a Preplant Soil Treatment in Warm-Season Sod Production

“…Previous research has indicated several fumigants or fumigant combinations have the potential to be used as methyl bromide alternatives in weed control. Nevertheless, very few performed as well as methyl bromide, especially for bermudagrass control, and problems stated above about the fumigation process still exist (8,15).…”

“…However, due to the toxic and volatile nature of most liquid fumigants, preplant fumigation can be both expensive and hazardous. Equipment limitations, toxicity issues, potential ground water contamination, personal protective equipment (PPE) requirements, and high summer temperatures of the Southeast can render this practice nearly impossible (15).…”