Abstract
Effect of several soil fumigants on snapdragon (Antirrhinum majus L.) production were evaluated in a commercial site in southeast Florida in 2003-04. Treatments consisted of methyl bromide (98%) + chloropicrin (2%), metam sodium, metam sodium + chloropicrin, solarization, and a nontreated control. All fumigant treatments and solarization initially reduced (P 0.05) weed populations compared to the nontreated control. Stubby-root nematode (Paratrichodorus spp.) numbers were reduced initially by methyl bromide + chloropicrin and by metam sodium + chloropicrin, but numbers resurged in solarized and fumigated plots after 4 months. Plant heights and flower yields were greater (P 0.05) in fumigated or solarized plots than in control plots. Early in the experiment, rain washed soil from an untreated border area into the experimental plots, and as a result, many plants became infected by a pathogen tentatively identified as Fusarium spp., which caused crown and stem rot symptoms. Losses in fumigated or solarized plots averaged 34.1%, whereas losses in nontreated control plots averaged 67.3%. These results illustrate the magnitude at losses that can occur if soilborne problems are not managed in cut flower production, as well as the potential for crop infection from untreated areas bordering the production site.
