|CABRERA, ALFONSO - University Of California|
|HANSON, BRAD - University Of California|
|KLONSKY, KAREN - University Of California|
|VASQUEZ, STEVE - University Of California - Cooperative Extension Service|
Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 9/2/2011
Publication Date: 10/30/2011
Citation: Wang, D., Cabrera, A., Gerik, J.S., Gao, S., Hanson, B., Browne, G.T., Klonsky, K., Vasquez, S. 2011. Methyl bromide alternatives for grape replant. International Conference on Methyl Bromide Alternatives and Emissions Reductions, San Diego, California, October 31-November 2, 2011. p. 30.1-30.3.
Interpretive Summary: Soil fumigation with either methyl bromide or Telone is used by grape growers in California to control soil-borne pests. However, the phase-out of methyl bromide and regulatory limitations on Telone require better understanding of methyl bromide alternatives. The objective of this project was to evaluate a number of alternatives for soil fumigation with methyl bromide for grape replant. In the past five seasons, we have conducted plot scale experiments at the USDA-ARS Parlier Station and a grower field demonstration trial near Fresno, CA. Soil nematodes were identified and quantified before and after each fumigation experiments. A wine grape (Cabernet Sauvignon) was transplanted in the plot experiments and a raisin grape (Selma Pete) was transplanted in the grower field trial for crop response assessment. Soil nematode populations showed drastic reductions in the fumigated plots in both the plot and the grower field trials. The yield data collected from the USDA ARS plot experiments clearly showed a positive fumigation effect on yield. Relatively low yields were found in the non-fumigated field plots and the low fumigant rate with bare soil plots. Yield results from the grower field trial also showed lower yield values in the untreated control than in any of the fumigated crop rows.
Technical Abstract: The project is part of the USDA-ARS Pacific Area-Wide Pest Management Program for Methyl Bromide Alternatives. The Critical Use Exemption (CUE) for methyl bromide (MB) on all grapes (wine, raisin, and table) is a short term solution until alternatives to MB are identified, and active research on MB alternatives is required for the approval of nominated CUE requests. The objective of this project was to evaluate a number of methyl bromide alternatives for grape replant. Plot scale experiments were conducted at the USDA-ARS Parlier Station and a grower field demonstration trial was carried out near Fresno, CA. The plot experiments consisted of eight treatments and a wine grape (Vitis vinifera var. Cabernet Sauvignon) as the bioassay crop. The grower field demonstration trial consisted of four fumigation treatments with a raisin grape (Vitis vinifera var. Selma Pete) as the bioassay crop. Yield data from the USDA ARS plot experiments showed a positive fumigation effect on the grape yield where relatively lower yields were found in the non-fumigated field plots and the low rate bare soil plots than in the full fumigation plots. Yield results from the grower field trial also showed a positive fumigation effect where lower yield values were observed in the untreated control than in any of the fumigated plots.