Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 11/3/2003
Publication Date: 11/3/2003
Citation: SCHNEIDER, S.M., TROUT, T.J., GERIK, J.S., RAMMING, D.W., AJWA, H.A. METHYL BROMIDE ALTERNATIVES FOR PERENNIAL NURSERIES - 1ST AND 2ND YEAR PERFORMANCE.. INTERNATIONAL CONFERENCE ON METHYL BROMIDE ALTERNATIVES AND EMISSIONS REDUCTIONS. 2003. Interpretive Summary: Soil fumigation with methyl bromide has commonly been used prior to planting field nurseries to insure a nematode-free product. Historically, methyl bromide has been effectively used to comply with the nursery clean propagative material regulations. Methyl bromide is being phased out because the U.S. Clean Air Act and the Montreal Protocol have determined that methyl bromide damages the stratospheric ozone layer. Growers of perennial nursery crops, such as trees, vines, and roses, will need alternatives to methyl bromide in order to continue to produce clean planting material following the ban on methyl bromide. In field trials, iodomethane+chloropicrin (MIDAS), tarped 1,3-dichloropropene +chloropicrin (Telone C35), and drip-applied 1,3-dichloropropene +chloropicrin (InLine), 1,3-dichloropropene (Telone EC), chloropicrin, and metam sodium achieved rootknot nematode control similar to methyl bromide at the beginning of the 2nd growing season in a rose field nursery, but performance of these materials at the end of the cropping cycle is not yet known, MIDAS is not yet registered, and use of 1,3-D is restricted in California by township caps. Tarped, shank-injected applications of MIDAS and chloropicrin gave better control of rootknot nematode than untarped, shank-injected applications in a commercial vine nursery, but tarping represents an additional cost. Untarped Telone C35 performed as well as tarped C35 in this trial. MIDAS, InLine, and sodium azide (Agrizide) reduced the citrus nematode populations at the time of planting comparable to methyl bromide to a depth of 150 cm, but performance at the end of the cropping cycle is not yet known. New materials evaluated here are potential tools for the management of nematodes under nursery conditions without methyl bromide.
Technical Abstract: Soil fumigation with methyl bromide has commonly been used prior to planting field nurseries to insure a high quality product and to meet the California Code of Regulations for clean propagative material. Historically, methyl bromide has been effectively used to comply with the nursery regulations. The phaseout of methyl bromide mandated by the U.S. Clean Air Act and the Montreal Protocol, an international treaty, will require growers to implement alternatives to methyl bromide by January 2005. Tarped, shank-injected chloropicrin (Pic), 1,3-dichloropropene (1,3-D)+Pic, and iodomethane (IM)+Pic achieved control of Meloidogyne spp., the rootknot nematode, at harvest comparable to methyl bromide on the highly susceptible Cabernet Sauvignon in a grapevine nursery trial. Among the non-tarped treatments, only 1,3-dichloropropene+Pic provided adequate control. At the beginning of the 2nd growing season of the rose nursery 2 year cropping system, shank-injected and drip-applied IM+Pic, 1,3-D+Pic under tarp, and drip-applied Pic and metam sodium all demonstrated rootknot nematode control comparable to that achieved with methyl bromide. Shank-injected 1,3-D+Pic that was not tarped did not control nematodes as well as methyl bromide in this trial. In a grapevine nursery field trial, IM+Pic, 1,3-D+Pic, and sodium azide, all drip-applied, controlled Tylenchulus semipenetrans, the citrus nematode population levels at the time of planting comparable to methyl bromide to a depth of 150 cm. Several drip- and shank-applied materials, both currently registered and experimental, show promise as alternatives to methyl bromide for one-year nursery crops, but performance for 2-year nursery crops, such as fruit trees and roses, must still be evaluated at the end of the cropping cycle.