Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 9/4/2003
Publication Date: 11/3/2003
Citation: SCHNEIDER, S.M., TROUT, T.J., BROWNE, G.T., AJWA, H.A., SIMS, J. VINEYARD REPLANT FIELD TRIALS. INTERNATIONAL CONFERENCE ON METHYL BROMIDE ALTERNATIVES AND EMISSIONS REDUCTIONS. 2003. Interpretive Summary: "Replant disorder" is a general term for the lack of vigor in a newly replanted vineyard as compared to vines planted in "non-vineyard" soil. Fumigation with methyl bromide prior to replanting is commonly used to alleviate the problem, but will not be allowed after Jan 2005. Alternatives are needed to insure the health and vigor of replanted vineyards. Field trials to evaluate potential alternatives for perennial crops must determine efficacy of pathogen control not only at the time of planting the new vineyard, but must assess the on-going performance of the methyl bromide alternatives during the early growth and fruiting years. After five growing seasons, iodomethane and 1,3-dichloropropene have controlled both the rootknot and citrus nematode as well as methyl bromide. The Harmony rootstock eliminated rootknot nematode, but supported high populations of the citrus nematode. Teleki 5C or Harmony rootstock following either iodomethane or 1,3-D soil treatments reduced both rootknot and citrus nematode below the detectable level. After 3 growing seasons, the levels of rootknot nematode in plots left fallow for 2 or 3 years before planting reduced rootknot nematode levels comparable to methyl bromide, but the levels of citrus nematode were similar to the levels in the untreated plots.
Technical Abstract: Methyl bromide has commonly been used when replanting vineyards to eliminate soilborne pests and pathogens. Due to its classification as an ozone depleter, methyl bromide is being phased out. Field evaluation of potential methyl bromide alternatives for perennial crops must determine not only efficacy of pest and pathogen control at the time of planting the new vineyard, but also the efficacy of pest control and impact on crop growth and yield during the early growth and fruiting years. In 1998, 9 soil treatments were applied to a 65-year old grape replant trial. After 5 growing seasons, shank injected iodomethane (400 lb/acre) and drip-applied 1,3-dichloropropene have controlled both the citrus and rootknot nematode populations comparable to the control achieved with methyl bromide. Applying the 1,3D in 60 mm water appears to be slightly more efficacious than applying it in 100 mm water. Harmony rootstock suppressed populations of the rootknot, but not citrus, nematode populations. Thompson Seedless yields were greatest in 1,3D treated plots and least in fallow+cover crop plots. In 2000, vines were planted following clean fallows of up to 3 years following the removal of a 65-year old vineyard. After 3 growing seasons, rootknot nematode populations were reduced by each additional year of fallow, but were least in methyl bromide treated plots. Citrus nematode populations showed no correlation with length of fallow and were significantly higher than populations in the methyl bromide treated plots. In 2001, 11 treatments were applied following removal of an 85-year old vineyard. After 2 growing seasons, iodomethane, InLine, and propargyl bromide have demonstrated control of rootknot nematode on Thompson Seedless comparable to control achieved with methyl bromide.