Phytosanitary Management of Dodder Seeds (Cuscuta spp.) Mixed in the Imported Seeds with the Dry Heat-treatment

Abstract

Proper actions such as discard, return or manufacturing should be taken to imported plants contaminated with quarantine weeds. Heat-treatment has been used as a processing method in many countries such as U.S., Australia, Canada as well as Korea. This study was carried to find appropriate heat-treatment methods for devitalizing dodder seeds mixed with plant seeds. Two species of dodder seeds and six imported seeds were treated for 1, 5, 10, 15, 30, 45 minutes or 1, 2, 4, 5, 6, 8 hours at the temperatures of 75℃, 80℃, 85℃, 90℃, 95℃, 10℃ and 120℃. According to the study, dodder seeds were devitalized at the conditions of 85℃ for 2 hours, 90℃ for 30 minutes, 95℃ and 100℃ for 15 minutes, 110℃ for 10 minutes and 120℃ for 5 minutes. Meanwhile, seed vigours of Cosmos bipinnatus and Callistephus chinensis had no difference when compared with untreated control at the heat-treatment conditions of 85℃ for 2 hours, 90℃ for 30 minutes.