Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 9/12/2010
Publication Date: 11/10/2010
Citation: Walse, S.S., Tebbets, J.S. 2010. Treatment of California stone fruit with methyl bromide or phosphine to eliminate peach twig borer, Anarsia lineatella. Methyl Bromide Alternatives and Emissions Research Conference, November 1-3, 2010, Orlando, Florida. p. 54:1-4.
Technical Abstract: The goal of this project is to develop postharvest chamber fumigations that ensure complete mortality of peach twig borer (PTB) in California stone fruit exports; results from preliminary toxicological and phytotoxicological research are presented. Fumigations with 1500 ppm phosphine over a 24 h exposure period at 40 F resulted in complete mortality of larvae (n = 236) placed inside peaches and nectarines. Methyl bromide fumigation with the APHIS T104a treatment schedule at 60 F resulted in complete mortality of PTB larvae (n = 171) placed inside peaches and nectarines. Plums sorb and desorb methyl bromide slower than peaches and nectarines. This translates into differential exposures when fumigations target pests on plums versus peaches and nectarines; the exposure is greater for surface pests, such as LBAM, and lower for internal pests, such as peach twig borer and Oriental fruit moth larvae. Longer methyl bromide residence times post-fumigation, which lead to greater methyl bromide residues, are also expected for plums relative to peaches and nectarines. Data indicates that with the minimum approved exposure of T104-a-1, “Angeleno” plum, “Autumn Flame” peach, and “Yellow” nectarine residues would be below the 0.05ppm methyl bromide in ~ 5, 3, and 3 days, respectively.