“Surfactant WK” for Thinning Peach Blossoms

Abstract

The surfactant, “Surfactant WK” (dodecyl ether of polyethylene glycol), was applied to peach trees [ Prunus persica(L.) Batsch] at full bloom three consecutive years. Blossoms died rapidly so that within 1 week dead blossoms could be distinguished easily from live blossoms. There were significant, linear relationships between concentration of “Surfactant WK” applied and percent blossoms removed, which was determined 1 to 2 weeks after treatment (R ²= 0.78***), and fruit set, which was determined 4 to 5 weeks after treatment (R ²= 0.86***). Trees were hand thinned according to commercial practices after treatment. Cropload, fruit weight and yield were similar across treatments at harvest indicating no negative effects by the chemical on productivity. “Surfactant WK” caused slight limb damage and overthinning at the highest concentrations. Based on the effectiveness, consistency, and lack of significant phytotoxicity, “Surfactant WK” demonstrated acceptability as a blossom thinner for peach trees in the southeastern U.S.