Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 19, 2010
Publication Date: March 1, 2010
Citation: Burelle, N.K., Rosskopf, E.N., Albano, J.P., Holzinger, J. 2010. Effects of Midas® on Nematode Populations in Commercial Floriculture Production in Florida. Journal of Nematology. Journal of Nematology.42(1):17-21. Technical Abstract: Cut flower producers currently have limited options for nematode control. Four field trials were conducted in 2006 and 2007 to evaluate Midas® (iodomethane:chloropicrin 50:50) for control of root-knot nematodes (Meloidogyne arenaria) on Celosia argentea var. cristata in a commercial floriculture production field in southeastern Florida. Midas (224 kg/ha) was compared to methyl bromide:chloropicrin (98:2, 224 kg/ha), and an untreated control. Treatments were evaluated for effects on populations of Meloidogyne arenaria J2 and microbivorous nematodes in soil through each season, and roots at the end of each season. Plant growth and root disease were also assessed. Populations of nematodes isolated from soil were highly variable in all trials early in the season, and generally rebounded by harvest, sometimes to higher levels in fumigant treatments than the untreated control. Although populations of nematodes in soil were not significantly reduced during the growing season, populations in roots and galling at the end of the season were consistently reduced with both fumigants compared to the untreated control. Symptoms of phytotoxicity were observed in Midas treatments during the first year and were attributed to Fe toxicity. Fertilization was adjusted during the second year to investigate potential fumigant/fertilizer interactions. Interactions occurred among soil treatments and fertilizer with respect to nematode populations isolated from roots and root galling at the end of the fourth season. This research demonstrates the difficulty of reducing high root-knot nematode populations in soil in subtropical conditions in production fields that have been fumigated repeatedly for years. Although soil populations may remain stable, root populations and disease can be reduced.