Submitted to: APS Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 6/6/2005
Publication Date: 6/15/2005
Citation: Gerik, J.S. 2005. Drip applied soil fumigants for liatris production.. APS Annual Meeting. Abstract Only. Interpretive Summary:
Technical Abstract: Liatris (gay-feather) is grown as a cut flower in open field soil on the central coast of California. Because of the 1 January 2005 methyl bromide (MB) phase out, cut flower growers need alternative treatments for pathogen and weed control. Field trials were established for 2 consecutive years to test various chemical combinations for Liatris production as an alternative to MB soil fumigation. The chemicals were applied by drip irrigation. In 2002, seven chemical were tested: chloropicrin, iodomethane, 1, 3-dichloropropene, sodium azide, furfural, allyl isothiocyanate, and metham sodium, all in various combinations. In 2003, dimethyl disulfide was also tested. At least 2 weeks following chemical application, the fields were planted with corms of i Liatris spicata/i (L.) cv. Callilepsis. Most treatments reduced populations of i Pythium/i spp. by 95 % and i Fusarium oxysporum/i by 50%. Metham sodium, furfural + metham sodium, sodium azide, and chloropicrin significantly reduced incidence of Liatris stem rot caused by i Sclerotinia sclerotiorum/i. The most prevalent weeds were cheese-weed, mustard, knotweed, clover, and annual bluegrass. Weed control was not acceptable either among any of the treatments. Viable alternatives to MB for cut flower production will require better treatments for weed control than was achieved in this study.