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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #129201
Title: APPLICATION AND CROP SAFETY PARAMETERS FOR SOIL FUMIGANTS.

Author
item CSINOS, A - UNIVERSITY OF GEORGIA
item Webster, Theodore
item SUMNER, D - UNIVERSITY OF GEORGIA
item Johnson, Alva
item DOWLER, C - RETIRED - USDA/ARS
item SEEBOLD, K - UNIVERSITY OF GEORGIA

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2002
Publication Date: 10/1/2002
Citation: Csinos, A.S., Webster, T.M., Sumner, D.R., Johnson, A.W., Dowler, C.C., Seebold, K.W. 2003. Application and crop safety paramenters for soil fumigants. Crop Protection. 21:973-982

Interpretive Summary: Methyl bromide is an effective soil fumigant used in the production of numerous fruit and vegetable crops. However, due to its suspected role as an ozone depleting substance, its use will soon be abolished. Immediate replacements for methyl bromide as a stop-gap measure have focused on currently registered compounds, such as metam sodium and 1,3- dichloropropene. Metam sodium alone and in combination with 1,3- dichloropropene plus 17% chloropicrin (1,3-D + C-17) were evaluated for pest efficacy and crop safety under polyethylene mulch film in pepper and tobacco seedling transplant production. In general, both the metam sodium alone and in combination with 1,3-D + C-17 compared favorably to methyl bromide. Short fumigation times and short aeration periods resulted in poor crop stands and vigor, while relatively long fumigation times and long aeration periods at the same rates typically resulted in high crop stands and vigor. Vigor and stand counts of the seedlings tended to be higher as the aeration time increased, suggesting phytotoxic residues from the fumigant treatment dissipated with time. Method of application of metam sodium, applied alone or in combination with 1,3-D + C-17 did not affect the pest efficacy. Caution regarding phytotoxicity must be exercised when seeding into soil fumigated with metam sodium alone or in combination with 1,3-D + C-17. Additional work will be needed to establish safety periods required prior to transplanting crops into fumigated soil.

Technical Abstract: Metam sodium alone and in combination with 1,3-dichloropropene plus 17% chloropicrin (1,3-D + C-17) were evaluated for pest efficacy and crop safety under polyethylene mulch film as alternatives to methyl bromide in solanaceous crop transplant production. Eight different weed species, 10 genera or species of fungi and several agronomic criteria were evaluated at three different sites. In general, both the metam sodium alone and in combination with 1,3-D + C-17 were highly efficacious when compared to methyl bromide. Short fumigation times and short aeration periods resulted in poor crop stands and vigor, while relatively long fumigation times and long aeration periods at the same rates typically resulted in high crop stand counts and vigor. The combination treatments tended to be more phytotoxic to germinating crop seeds than metam sodium alone. Vigor and stand counts of the seedlings tended to be higher as the aeration time increased, suggesting phytotoxic residues from the fumigant treatment dissipated with time. Method of application of metam sodium, either injected with chisels or sprayed onto the soil surface and incorporated with a tractor-powered tiller alone or co-applied with 1,3-D + C-17 chisel injected, did not affect the pest efficacy of the treatments. Caution regarding phytotoxicity must be exercised when seeding into soil fumigated with metam sodium alone or in combination with 1,3-D + C-17. Additional work will be required to establish safety periods required prior to transplanting crops into fumigated soil.