|WALTERS, THOMAS - Washington State University|
|PATRIKA, MICHAEL - Washington State University|
Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/1/2009
Publication Date: 10/29/2010
Citation: Walters, T., Patrika, M., Zasada, I.A., Pinkerton, J.M. 2010. Methyl bromide alternatives for raspberry nurseries. Proceedings of Methyl Bromide Alternatives Conference. Available:http://mbao.rg/2009/Proceedings/026WaltersTRBnurssummary09.pdf
Technical Abstract: Raspberry nurseries must produce plants free from disease to meet marketplace and export requirements. Minor disease infestations in nurseries can cause severe epidemics in production fields. Raspberry nurseries presently qualify for critical use and quarantine/preshipment exemptions to use Methyl Bromide (MB), but there is increasing pressure to find alternatives. Root rot caused by Phytophthora rubi (PR) and the root lesion nematode Pratylenchus penetrans (PP) are the most serious root diseases of red raspberries in many growing regions. Crown gall (Agrobacterium tumefasciens, AT) is common in the coarse-textured soils favorable to raspberry nursery production. Soil fumigation with MB reduces but does not consistently eliminate crown gall. Improved AT control would be a very attractive feature of a MB alternative for raspberry nurseries. Methyl bromide is also valued by raspberry nurseries for its role in eliminating other pathogens and weeds. Our objective was to evaluate alternatives to MB:chloripicrin fumigation for reduction of pathogens and weeds in raspberry nursery production. In field evaluations, MIDAS 50:50 (iodomethane) at 350 lb/A under high density polyethylene (HDPE) film and Telone C-35 at 39 gal/A under virtually impermeable film (VIF) were as effective as MB:pic in controlling PR and PP. MIDAS is quite expensive, and it is not yet labeled in Washington and California, the major states for raspberry nursery production. Telone C-35 is available, but widespread implementation of this alternative would require a better system for gluing the VIF film. Telone C-35 under conventional HDPE film controlled PR and PP well, and may be suitable when AT is not a problem. MIDAS 50:50 at 175 lb/A under HDPE or VIF films did not provide adequate control of PR and AT in these trials.