Location: Water Management Research
Title: Therapeutic chemical treatment of grape vines for root diseases Authors
Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: October 29, 2013
Publication Date: November 3, 2013
Citation: Wang, D., Cabrera, A., Gerik, J.S., Gan, J. 2013. Therapeutic chemical treatment of grape vines for root diseases. Proceedings of Methyl Bromide Alternatives Conference. p. 19-1 - 19-2. Interpretive Summary: For perennial vine and tree crops, soil nematodes and pathogens that cause root diseases are typically treated with soil fumigation during replant. Methods for treating soil pests during the crop production period are lacking. Field trials were conducted to evaluate treatment of soil nematodes and fungi in established grape vines using soil applied dimethyl disulfide. Results showed that post-plant fumigation with dimethyl disulfide effectively controlled nematodes and did not cause phytotoxicity, but the treatment was less efficacious against fungal pathogens. The findings are valuable for potentially creating a new method of nematode control in established vine and tree crops.
Technical Abstract: There is a need to develop post-plant treatment of soil pests for perennial vine and tree crops. Field trials were performed to evaluate post-plant treatment of established grape vines (Vitis vinifera var. Thompson Seedless) with known problems of soilborne plant-parasitic nematodes and pathogens using dimethyl disulfide. The fumigant was applied using a drip irrigation system during dormancy and at four dosages plus an untreated control. Soil samples were taken from which all plant parasitic nematodes were extracted, identified, and counted, and soil pathogens were enumerated. Plant toxicity or response to the fumigation was assessed by measuring the growth rate of buds, leaf stomatal conductance, root vitality, and yield. The field trial was repeated for two years. The post-plant treatment reduced the number of citrus (Tylenchulus semipenetrans), root-knot (Meloidogyne spp.), pin (Paratylenchus spp.), and ring (Mesocriconema xenoplax) nematodes in the soil by about 60% at the 112 kg/ha rate and over 90% at the 897 kg/ha rate. The treatment did not significantly affect soil populations of F. oxysporum; however, approximately a 50% reduction was observed for P. ultimum. Overall no phytotoxic effect was observed.