Comparison of 1,3-Dichloropropene and Methyl Bromide for Control of Xiphinema index and Grapevine Fanleaf Degeneration Complex

¹ Department of Nematology, University of California, Davis, CA 95616.
² Department of Plant Pathology, University of California, Davis, CA 95616.

Preplant soil fumigations with methyl bromide (MBr) at 448 kg/ha covered with polyethylene and MBr at 672 kg/ha (uncovered) were compared with 1,3-dichloropropene (1,3-D; Telone II) at 1560 kg/ha in a vineyard near Rutherford, California. The treatments were applied after 20-year-old vines in severe decline from grapevine fanleaf virus/Xiphinema index damage were pulled following harvest in 1979. The site was treated in 1980 and planted in 1981. X. index were found after two growing seasons in half of the samples from both MBr treatments and in all of the 1,3-D samples. Fumigation reduced the rate of grapevine fanleaf virus reinfection. Six years after planting, the virus was present in only 5% of vines in the block treated with MBr (covered) and 15% of vines in soil treated with MBr (uncovered), as compared with 36% of vines in the 1,3-D-treated block. Untreated vines showed 30% to 66% infection. Yields, calculated as average kg/vine in the three fumigation treatments, were superior to yields from untreated checks in each of four bearing years.

Key words: soil fumigation, soil-borne virus, 1,3-dichloropropene fumigation, preplant soil fumigation, methyl bromide fumigation

Submitted on November 24, 1987