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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #258845


item Rosskopf, Erin
item Burelle, Nancy
item Nissen, Eric
item Nissen, Ole
item Hartman, Bob
item Skvarch, Ed
item Mcsorley, Robert
item Swaford, T.j.
item Brooks, Shan
item Register, Kyle
item Owens, Clay

Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: 10/11/2010
Publication Date: 10/15/2010
Citation: Rosskopf, E.N., Burelle, N.K., Nissen, E., Nissen, O., Hartman, B., Skvarch, E., Mcsorley, R., Swaford, T., Brooks, S., Register, K., Owens, C. 2010. EVALUATION OF CURRENTLY AVAILABLE ALTERNATIVES TO METHYL BROMIDE FOR ORNAMENTAL CROP PRODUCTION IN FLORIDA. Proceedings of Methyl Bromide Alternatives Conference. 82:1-4.

Interpretive Summary:

Technical Abstract: Studies were designed to test the efficacy of the chemical alternatives, Midas™ (iodomethane:chloropicrin (pic) 50:50 [MI 50:50] and 98:2 [MI 98:2], Arysta LifeScience Corp., Cary, NC) and dimethyl disulfide:pic (Paladin™ 79:21 [DMDS], United Phosphorous, Inc., King of Prussia, PA) compared with methyl bromide (MeBr) as a standard at the scale appropriate for commercial production of the selected crops. All materials were applied by commercial applicators. Trials were conducted in two locations on commercial ornamental farms. The studies were replicated, randomized complete blocks with split plots to accommodate multiple cultivars in each location. The trials were repeated with treatments maintained in the same plots over multiple seasons. The cut flower trial was performed in Hobe Sound, FL. There were no significant differences between treatments with regard to total weeding time in either year, but there were significantly more weeds per meter in the DMDS treatment than in the others in the second year. Principal weed problems were clover (Trifolium repens), spotted spurge (Chamaesyce maculata), goosegrass (Eleusine indica), and portulaca (Portulaca oleracea). The total cut stems and average number of cuts per plant did not differ between treatments in either year. There were no significant populations of root-knot (RKN) or other parasitic nematodes at the Hobe Sound location in either year 1 or 2 and no galling occurred on roots in any treatment in either season. In the second year of this trial, the total number of weeds per plot was higher in DMDS-treated plots, but this did not impact the total number of harvested marketable stems. Two full-field demonstration trials using MI 98:2 have been established at this location for the production of multiple cut flower species. In these fields, the use of VIF film was accomplished with standard tarp glue, but applications were made to a relatively small area, under 1 acre each. The first year of the caladium trial at Zolfo Springs included two formulations of MI 98:2 (100 lb/A) and MI 50:50 (160 lb/A), DMDS (79:21 at 60 gal/A), and MeBr:pic (98:2 at 180 lb/A), all applied under high barrier, Blockade® plastic mulch (Pliant Corp., Chippewa Falls, WI) using raised beds. A shank application of Telone II was applied 12-14” deep to the entire site before application of the test fumigants. Each treatment was replicated four times with each plot approximately 0.5 A, split into sub-plots planted to four cultivars. In the second year, the same treatments were applied using flat fumigation. There were significant cultivar by fumigant interactions with regard to fungal colonization of caladium roots, particularly for Fusarium, Trichoderma, and Pythium. Root-knot nematodes in soil were equally well controlled by all fumigants early in the season. However, root-knot nematodes in soil rebounded in all treatments by harvest, eight months after fumigation. Root-knot nematode numbers in roots and root galling were more dependent upon cultivar than on fumigant. Due to heavy weed pressure, weeds were weighed at the end of season rather than counted. Weed weights were highest in MI 98:2. The total number of bulbs produced, which includes both marketable bulbs and non-marketable seed stock, was also dependent upon the interaction between cultivar and fumigant. In the caladium trial, MI 98:2 application resulted in consistent reductions in nematode populations, although cultivar selection will play a major role in the success of any alternative fumigant applied in this system. The additional time required prior to plastic removal was also an issue in the caladium trials due to the quantity of blowing soil being deposited on the plastic prior to removal in a full field tarping. This caused a significant increase in the cost of removal and disposal of plastic. A grower field da