Location: Water Management ResearchTitle: Pacific area wide program for methyl bromide alternatives – Ornamentals) Author
Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 9/30/2012
Publication Date: 11/6/2012
Citation: Gerik, J.S., Dangi, S., Ajwa, H. 2012. Pacific area wide program for methyl bromide alternatives – Ornamentals. International Conference on Methyl Bromide Alternatives and Emissions Reductions. p. 21. Interpretive Summary: During the past five years 13 different field trials were conducted to test alternatives to methyl bromide/chloropicrin soil fumigation for the production of field grown cut flowers and ornamental bulb crops in California. These trials were conducted on various growers' farms in the coastal areas of the state from San Diego to Watsonville. Most of the alteratives tested involved soil fumigation using various combinations of fumigants containing Telone, chloropicrin, and methyl isothiocyanate generators, but also included steam and biological control agents. The generalized results indicate that the chemical soil fumigants controlled Pythium spp. as well as the standard methyl bromide/chloropicrin, but did not for control Fusarium oxysporum and weeds as well. The steam and biological agent treatments were very inconsistent.
Technical Abstract: During the past 5 years the following field trials have been conducted as part of the Pacific Area-Wide program for cut flowers and ornamentals using various combinations of 1, 3-dichloropropene, chloropicrin, and metam: 1) Drip demonstration trial with field-grown calla lilies at Golden State Bulb Growers in Moss Landing, CA. 2) Shank demonstration trial with field-grown calla lilies using at Golden State Bulb Growers in Soledad, CA. 3) In-season application of low doses of methyl iodide, DMDS, furfural, and bromoethanol for pest control in field-grown calla lilies, at Golden State Bulb Growers in Moss Landing and Soledad, CA. 4) Shank and drip demonstration trial with field-grown Gladiolas Glad-A-Way Gardens in Santa Maria, CA. 5) Shank and drip demonstration trial with field-grown Ranunculus at Mellano & Co. in Carlsbad, CA. 6) Drip demonstration and solarization trial with greenhouse-grown Irises at All Season’s Flowers in Nipomo, CA. 7) Drip demonstration and solarization trial with greenhouse-grown Freesia at All Season’s Flowers in Nipomo, CA. 8) Drip demonstration and solarization trial with greenhouse-grown snapdragons at Skyline Flowers, in Oxnard, CA. 9) Drip demonstration and plastic mulch trial with field-grown Ranunculus 2008 at Mellano & Co. in Carlsbad, CA. 10) A biological pesticides trial with field-grown calla lilies at Golden State Bulb Growers in Moss Landing, CA. 11) Steam demonstration trial with field-grown Ranunculus at Mellano & Co. in Carlsbad, CA. 12) Drip and steam demonstration trial with field grown sun flower 2010 at Pyramid Flowers in Oxnard, CA. Results from these field demonstration trials indicate that the best alternatives to methyl bromide/chloropicrin soil fumigation is a combination of 1, 3-dichloropropene with chloropicrin followed a week later with an application of metam sodium. This treatment routinely controlled Pythium spp., but was inconsistent for control of Fusarium oxysporum and weeds. The biological pesticides were, for the most part, not effective at controlling Pythium spp. Use of steam for control of soilborne pathogens also was inconsistent. Findings from these field trials have been presented at three field days, five methyl bromide conferences, two APS meetings, and published in two peer-reviewed journal articles. In response to these trials/demonstrations, the major grower of calla lily in California has transitioned away from methyl bromide. They are now using drip applied 1, 3-D/CP and MITC for pathogen and weed control in their crops. An ornamental crop field trial is ongoing at Moss Landing, CA using chloropicrin and 1, 3-dichloropropene and non-permeable tarps as alternatives to methyl bromide in an attempt to control calla lily root rot using reduced rates of fumigants.