Chemical Alternatives to Methyl Bromide

Three soil fumigants were evaluated at a nursery in Georgia and one in South Carolina. Seedbed density and seedling development were compared among plots treated with tarped and not tarped dazomet at 140 and 280 lbs/ac, tarped and not tarped chloropicrin at 125 and 250 lbs/ac, tarped MC33 at 350 lbs/ac and non-fumigated plots. Differences among treatments occurred only in South Carolina where both initial seedbed density and harvested seedlings differed with treatments. Among harvested seedlings, the high rate of dazomet and chloropicrin were not significantly different from MC33 but the low rates and controls were inferior. In a second study at the South Carolina nursery, dazomet (150 and 300 lbs/ac tarped and not tarped), MC33 (350 lbs/ac tarped), 1,3-D (290 lbs/ac tarped), metham -sodium (400 lbs/ac tarped and not tarped), dazomet (150 lbs/ac) plus chloropicrin (115 lbs/ac tarped), and metham -sodium plus chloropicrin (400 and 115 lbs/ac tarped) were evaluated with respect to weed control. MC33 and 1,3-D had the best herbicidal activity.