industry has relied heavily upon the use of methyl bromide/chloropicrin (MBC) as a key soil treatment for crop production. It has been used as a preplant fumigant to control soil-borne fungi, nematodes, bacteria, and weeds, as well as to kill the soil
Inga A. Zasada, Clyde L. Elmore, Lani E. Yakabe and James D. MacDonald
Theodore P. McAvoy and Joshua H. Freeman
The use of MBr has been instrumental for the management of soilborne pests in many vegetable crops that use the plasticulture production system. Vegetable producers rely on soil fumigants to maintain successful production. However, MBr was found to
Robert E. Uhlig, George Bird, Robert J. Richardson and Bernard H. Zandstra
Fumigants are used to control soil-borne pests to obtain larger yields of high-quality horticultural products ( Messenger and Braun, 2000 ). Methyl bromide has been the most widely used fumigant, with 68,424 t used worldwide in 1996. The United
Charles L. Wilson, Jose M. Solar, Ahmed El Ghaouth and Deborah R. Fravel
An apparatus was developed for the rapid and facile evaluation of soil fumigants in a controlled manner using small volumes of soil. The apparatus consisted of a manifold to which were attached six canisters containing a loamy sand soil (adjusted to –100 kPa soil water potential). The soil was infested with either conidia of Fusarium oxysporum or Trichoderma harzianum; sclerotia of Sclerotinia minor; ascospores of Talaromyces flavus; vermiculite colonized with Pythium aphanidermatum; or beet (Beta vulgaris L., cv. Detroit Red) seed colonized with Rhizoctonia solani. Using nitrogen gas (N2) as a carrier gas, either N2 or N2 plus benzaldehyde was passed continuously through the soil for 24, 48, or 72 hours. At all three exposure times, benzaldehyde + N2 reduced viability of R. solani and S. minor, and reduced populations of P. aphanidermatum and T. harzianum. Populations of F. oxysporum were reduced after 48 and 72 hours of exposure to benzaldehyde, whereas populations of T. flavus were reduced only after 72 hours of exposure. Fumigation with benzaldehyde + N2 for 24 hours did not affect soil pH 1 week after exposure, but fumigation for 48 or 72 hours temporarily lowered pH from an average of 6.86 to 5.57 and 5.32, respectively. The biocontrol fungus, T. flavus, was less sensitive to benzaldehyde than the pathogens or the biocontrol fungus, T. harzianum. Thus, combining T. flavus with benzaldehyde to enhance biocontrol may be possible.
S.D. Nelson, S.J. Locascio, L.H. Allen Jr., D.W. Dickson and D.J. Mitchell
Methyl bromide (MeBr) is an important and effective soil fumigant commonly used to control weeds and soilborne pests. Because MeBr has been implicated as a contributor to the depletion of stratospheric ozone, it is scheduled for phaseout by 2005. This study examined nonchemical and chemical practices as alternatives to MeBr. Off-season flooding followed by a series of soil preplant chemical treatments [MeBr with 33% Pic; 1,3-D mixed with 17% (C-17) and 35% (C-35) Pic combined with Peb; and metam-Na combined with 1,3-D and Peb were evaluated on spring tomato (Lycopersicon esculentum Mill.) and eggplant (Solanum melongena) production in northern Florida. Pest control and tomato and eggplant yields were not significantly different between the flooded and non-flooded control plots. The most effective alternatives to MeBr were 1,3-D and Pic mixtures (C-17 and C-35) combined with Peb. Tomato and eggplant yields for these chemicals were statistically equivalent to that of MeBr. Tomato, but not eggplant, yield and nematode control were poor with metam-Na combined with 1,3-D and Peb in comparison to the other fumigant combinations. Chemical names used: 1,3-dichloropropene (1,3-D); trichloronitromethane [chloropicrin (Pic)]; S-propyl butyl(ethyl)thiocarbamate [pebulate (Peb)]; sodium N-methyldithiocarbamate (metam-sodium (metam-Na)].
James P. Gilreath, Bielinski M. Santos, Joseph W. Noling, Salvadore J. Locascio, Donald W. Dickson, Erin N. Rosskopf and Steven M. Olson
Field studies were conducted in three Florida locations (Bradenton, Gainesville, and Quincy) during 1998-99 and 1999-2000 to: 1) compare the performance of two transplant systems under diverse MBr alternative programs in `Chandler' strawberry (Fragaria ×ananassa), and 2) determine the efficacy of these treatments on soilborne pest control in strawberry. Fumigant treatments were: 1) nonfumigated control, 2) methyl bromide plus chloropicrin (MBr + Pic) at a rate of 350 lb/acre, 3) Pic at 300 lb/acre and napropamide at 4 lb/acre, 4) 1,3-dichloropropene (1,3-D) plus Pic at 35 gal/acre and napropamide at 4 lb/acre, 5) metam sodium (MNa) at 60 gal/acre and napropamide at 4 lb/acre, and 6) MNa followed by 1,3-D at 60 and 12 gal/acre and napropamide at 4 lb/acre, respectively. Strawberry transplants were either bare-root or containerized plugs. There were no significant fumigant by transplant type interactions for strawberry plant vigor and root weight per plant, whereas ring nematode (Criconema spp.) and nutsedge (Cyperus rotundus and C. esculentus) populations, and total marketable fruit weight were only infl uenced by fumigant application. The nonfumigated plots had the lowest strawberry plant vigor and root weight per plant in all three locations. In most cases, plant vigor and root biomass per plant increased as a response to any fumigant application. With regard to the transplant type, bare-root transplants had similar plant vigor as plugs in two of the three locations. Fumigation improved nutsedge and ring nematode control. All fumigants had higher early and total marketable yield than the nonfumigated control, whereas transplant type had no effect on total fruit weight.
Steve Kovach, James Brown, Walter Hogue, Larry Curtis and William S. Gazaway
Drip-irrigated tomato (`Sunny') plants were treated with five levels of fumigant in combination with three levels of mulch. Fumigants were metham sodium at two rates, 475 and 950 L/ha, a 67% methyl bromide + 33% chloropicrin formulation (164.5 kg/ha, and a 98% methyl bromide + 2% chloropicrin formulation (329 kg/ha). Mulching levels were 1.25 mil silver on black polyethylene (plastic), blue-black latex mulch sprayed over the plant beds, and no mulch. Plants treated with metham sodium (950 L/ha) had a significantly higher number of marketable fruit than plants treated with no fumigant or the 98% methyl bromide + 2% chloropicrin formulation. Marketable fruit weight was not significantly affected by the five fumigation levels. Plants grown with black plastic mulch had a significantly higher marketable yield than plants grown with no mulch, 58,100 kg/ha vs. 50,800 kg/ha, respectively. The level of mulching did not significantly affect the marketable number of fruit.
Joseph F. Costante, Wesley R. Autio and Lorraine P. Berkett
`Rogers Red McIntosh' apple (Malus domestica Borkh.) trees on MM. 111, MM. 106, M.7a, or M.26 were planted in 1984 on an old orchard site, diagnosed with an apple replant disease (ARD) problem. Soil treatments included Telone c-17, Vorlex, Nemacur 3, or not treated. After six years, tree performance problems usually associated with severe ARD did not develop. Lesion nematode [Pratylenchus penetrans (Cobb) Filipjev and Schuurmans-Stekhoven] populations feeding within or on the surface of roots were not affected by nematicide treatments nor rootstocks, even though slightly damaging levels were found in 1986. At the end of the sixth growing season, trunk cross-sectional areas were similar for trees in treated and in untreated soils. Trees on MM. 111 and MM. 106 were the largest, and those on M.26 were the smallest. Cumulative yield was not influenced by soil treatments, but trees on MM. 111 produced the greatest cumulative yields, whereas trees on M.26 were the most yield efficient.
Jayesh B. Samtani, Husein A. Ajwa, Rachael E. Goodhue, Oleg Daugovish, Zahanghir Kabir and Steven A. Fennimore
). Improved retention of fumigants in soil under VIF also provides more opportunity for soil degradation of fumigants rather than release into the atmosphere ( Wang and Yates, 1998 ). Use of VIF as a tarp can reduce 1,3-D + Pic needed for effective soil
Steven A. Fennimore, Milton J. Haar, Rachael E. Goodhue and Christopher Q. Winterbottom
·ha −1 ; however, control of Ipomea spp. weeds with IM was less than MBPic ( Unruh et al., 2002 ). Iodomethane can be used in combination with other fumigants such as Pic to increase its spectrum of activity against soil pests such as yellow nutsedge