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United States Department of Agriculture

Agricultural Research Service

Research Project: Alternatives to MEBR for California Cropping Systems Title: Calla lily production with methyl bromide alternatives – Year 2

Authors
item Gerik, James
item Dangi, Sadikshya -
item Ajwa, Husein -

Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: September 30, 2012
Publication Date: November 6, 2012
Citation: Gerik, J.S., Dangi, S., Ajwa, H. 2012. Calla lily production with methyl bromide alternatives – Year 2. International Conference on Methyl Bromide Alternatives and Emissions Reductions. p. 23.

Interpretive Summary: A trial was started near Moss Landing California to determine the lowest effective rates of the two primary methyl bromide alternatives for calla lily production when used with virtually impermeable film. Three rates each of InLine and Pic-Clor 60 EC were applied through drip irrigation tape to plots of raised beds. A week later, one of four rates of K-Pam was also applied to the plots and calla lily was seeded a few weeks later. Soil samples were collected and populations of Fusarium oxysporum and Pythium spp. were determined. All rates of both fumigants reduced the populations of both organisms; Pythium spp. was controlled to a greater extent than Fusarium oxysporum. The fumigants had no effect on stand counts. This is a preliminary report of this experiment and more results will be forth coming.

Technical Abstract: Cut flower and ornamental bulb industries rely heavily on a methyl bromide/chloropicrin (MB/Pic) mixture as a key pest management tool. The loss of MB will seriously affect the cut flower and bulb industry, and, in the future, will require growers to use alternative fumigants. Past experiments have shown that calla lily can be successfully grown using alternative fumigants. These have included combinations of chloropicrin (Pic), 1, 3-dichloropropene (1, 3-D), and potassium metam (K-Pam). An experiment is being conducted to determine the lowest effective rates that these chemicals can be successfully used to grow this crop using virtually impermeable film (VIF). This is a second report on a trial started in 2011 that will conclude in 2012. A trial was established near Moss Landing, California on a commercial calla lily farm. The plots were approximately 500 feet long and consisted of raised beds 72 inches wide covered with VIF. The main plots were fumigated with either InLine (1, 3-D 60.8%, Pic 33.3%) or Pic-Clor 60 EC (Pic 56.7 %, 1, 3-D 37.1%) or left untreated. Both fumigants were applied at three rates: 20, 17, and 14 gallons per acre. All fumigants were applied through five drip irrigation tapes on the surface of the beds beneath VIF, the tapes delivered water at a rate of 0.22 gallons per minute per 100 feet. The fumigants were applied in 1 inch of water on 18 & 19 May 2011. The main plots were divided into four sub-plots. One week after the initial fumigation the sub-plots were fumigated with one of four rates of K-Pam: 0, 28 34, or 40 gallons per acre. On 16 June 2011 the beds were seeded with 15 lines of calla lily. On 7 June 2011, soil samples were collected from each sub-plot. The samples consisted of a composite of five 1 inch diameter soil cores 6 inches long. The samples were returned to the lab and populations of Fusarium oxysporum and Pythium spp. were determined by dilution plating on Komada’s medium and P5ARP medium. On 21 July stand counts were made on 1 meter long segments of the bed in each sub plot. The trial will continue until the end of 2012 when the bulbs will be harvested and yield results collected. At this time we can present results of the pathogen populations test and stand establishment. The populations of Fusarium oxysporum were reduced at all rates of the primary fumigants and especially with the high rates of K-Pam. A species of Pythium is the primary disease causing agent of root rot of calla lily. The fumigants did a much better job in reducing populations of Pythium spp. compared to F. oxysporum; we have observed this before in past experiments when using these fumigants. Seedling stand counts were made on 21 July 2011. The stand of calla lily was not affected by the soil treatments. Disease ratings were made on 21 August 2012. All rates of the primary fumigants did not result in lower disease ratings. All rates of K-Pam decreased the disease ratings. It appears that these low rates of methyl bromide alternatives are not sufficient for controlling disease in this cropping system even when used with VIF. Yield data will be collected in the fall of 2012.

Last Modified: 10/20/2014
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