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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 #200212
Title: EVALUATION OF MIDAS™ FOR PRODUCTION OF ORNAMENTAL COCKSCOMB (Celosia argentea) IN FLORIDA

Author
item Rosskopf, Erin
item Burelle, Nancy
item Driggers, Randall
item KREGER, ROBERT - ARYSTA LIFE SCIENCES
item HOLZINGER, JOHN - HOLZINGER FLOWERS, INC.

Submitted to: Proceedings of Methyl Bromide Alternatives Conference
Publication Type: Proceedings
Publication Acceptance Date: 10/11/2011
Publication Date: 11/6/2006
Citation: Rosskopf, E.N., Burelle, N.K., Driggers, R.E., Kreger, R., Holzinger, J. 2006. Evaluation of midas™ for production of ornamental cockscomb (celosia argentea) in florida. Proceedings of Methyl Bromide Alternatives Conference. 37:1-4.

Interpretive Summary: A large number of floriculture crops in Florida are dependent upon the use of methyl bromide soil fumigation for control of a wide variety of pests. These include weeds, nematodes, and soilborne fungal plant pathogens. This industry is currently able to continue using methyl bromide for soil fumigation through the critical use nomination process, but alternatives to methyl bromide must be tested for this industry. A field trial was conducted in Martin County, Florida to determine the efficacy of methyl iodide, formulated at the commercial product Midas, consisting of a 50:50 mixture of methyl iodide and chloropicrin, for production of the cut flower, ornamental cockscomb (Celosia argentea var. cristata). Midas is currently undergoing registration evaluation with the US Environmental Protection Agency. Treatments in this trial included methy bromide:chloropicrin (98:2 formulation at 224 kg/ha), Midas (224 kg/ha), and an untreated check. All treatments were covered with metalized film. The impacts of the treatments on weeds, disease, nematodes, and cockscomb growth were monitored. Weed counts taken at plastic removal consisted principally of nutsedge in the untreated check. Weed counts continued to be highest in the untreated check at midseason and harvest with no significant differences in weed counts between the methyl bromide or Midas™ treated plots. Fresh and dried weed weights were highest in the untreated check at both collection times. There were no significant differences between the methyl bromide and Midas™ treated plots. Cockscomb stem diameters and plant heights were lowest in the untreated check at both sampling dates, with no differences between the fumigants. The incidences of wilted and stunted plants were highest in the untreated plots and there were no differences between fumigants. The same was true for the number of Fusarium and Pythium colony forming units. Number of stems and number of marketable stems were highest in the fumigated treatments and were significantly higher than the untreated check. Although the application of Midas™ required equipment modification that is still being improved, the material provided adequate weed and disease control and produced cockscomb yields that were comparable to methyl bromide.

Technical Abstract: A field trial was conducted to evaluate Midas™ (iodomethane:chloropicrin 50:50) for production of ornamental cockscomb (Celosia argentea var. cristata) in Martin County, Florida in spring 2006. Treatments included an untreated check, Midas™ applied at 224 kg/ha (200 lb/A), and methyl bromide:chloropicrin (98:2) applied at 224 kg/ha (200 lb/A). In two previous trials, this reduced rate of methyl bromide (224 kg/ha) applied under virtually impermeable film (Klerk’s Plastic Products Manufacturing, Inc., Clarksburg, SC) was found to be comparable to the grower standard (Rosskopf, unpublished). All treatments were covered with metalized film (Canslit, Inc., Montreal, Quebec, Canada) at the time of fumigation. Each plot was 1.8 m wide by 30.5 m long. Treatments were replicated four times and plots were arranged in a randomized complete block design. Plastic mulch was removed 15 days after fumigation and cockscomb was seeded five days later. The cockscomb cultivar Chief Rose was used in the test area. Data on weed density and weight, fungal colony forming units, disease incidence, gall ratings, nematode counts, and plant growth parameters were collected from four meter-long sample areas within each replication. Data was collected at mid-season (40 days after seeding) and at harvest (90 days after seeding). Plants were harvested and destructive sampling performed at 97 days after seeding. Weed counts taken at plastic removal consisted principally of nutsedge in the untreated check. Weed counts continued to be highest in the untreated check at midseason and harvest with no significant differences in weed counts between the methyl bromide or Midas™ treated plots. Fresh and dried weed weights were highest in the untreated check at both collection times. There were no significant differences between the methyl bromide and Midas™ treated plots. Cockscomb stem diameters and plant heights were lowest in the untreated check at both sampling dates, with no differences between the fumigants. The incidences of wilted and stunted plants were highest in the untreated plots and there were no differences between fumigants. The same was true for the number of Fusarium and Pythium colony forming units. Number of stems and number of marketable stems were highest in the fumigated treatments and were significantly higher than the untreated check. Although the application of Midas™ required equipment modification that is still being improved, the material provided adequate weed and disease control and produced cockscomb yields that were comparable to methyl bromide.