Submitted to: Mint Industry Research Council 2002 Research Reports
Publication Type: Proceedings
Publication Acceptance Date: 1/1/2004
Publication Date: 1/1/2004
Citation: BOYDSTON, R.A., BAKER, R. MINT WEED RESEARCH REPORT. MINT INDUSTRY RESEARCH COUNCIL 2003 RESEARCH REPORTS, LAS VEGAS, NV. p. 25. 2004.
Technical Abstract: Weeds present in mint reduce oil yield and quality of mint oil. Research was conducted to determine the yield response of spearmint infested with field bindweed after treating with 2,4DB and MCPB; determine effect of herbicide application to native spearmint on beneficial arthropods; identify and evaluate new herbicides for use in mint crops; determine the effect of tank mixing paraquat with flumioxazin and sulfentrazone when applied alone and with two adjuvants; and to determine salsify time of emergence and seed survivability in establishment in mint and response to herbicides applied at several growth stages. One spring application of MCPB at 1 lb ai/a suppressed field bindweed and increased oil yield of mint compared to nontreated checks. Currently registered mint herbicides or new non-registered herbicides had no effect on beneficial mite populations in native spearmint. Fluroxypyr, flufenacet, cloransulam, bromoxynil+MCPA, mesotrione, sulfentrazone, flumioxazin, and clomazone were tested for selectivity on spearmint or peppermint in eight separate field trials. Fluroxypyr applied to dormant mint controlled several problem weeds without injury to mint and increased oil yield in peppermint compared to weedy checks. Flufenacet, cloransulam, MCPA, and mesotrione injured mint excessively and do not warrant further testing. Paraquat greatly increased control of emerged winter annual weeds when applied with flumioxazin or sulfentrazone to dormant peppermint, whereas COC and nonionic surfactant had little effect on flumioxazin or sulfentrazone efficacy. Salsify seed longevity, time of emergence, and growth and development were evaluated in peppermint. Most salsify emerged several weeks after planting and seed longevity in soil was minimal at six to twelve months. Four herbicides were evaluated for control of salsify when applied in various growth stages in greenhouse trials. Salsify was susceptible to terbacil, sulfentrazone, oxyfluorfen, flumioxazin, and clopyralid applied pre up to the 4-lf stage of growth.