After the implementation of S + N procedures, trees in 11 of 16
districts investigated had no symptoms of PWD over 2 years, indicating
suppression of the PWD epidemic (Fig. 4). The suppression was achieved only in Youngam among the 18 conventional control
(CF, CP + N) districts investigated (Table 1). It was significantly different
among the three control regimes (2 = 12.7, df = 2, p < 0.01).
Suppression was recently declared in Mokpo, where no PWD wilt pines had not been found in the 2 years since 2008. However, suppression
was achieved in Mokpo 7 years after first detection of
PWD wilt pines. During the early years (2001–2003) of the infection
period, PWD from Mokpo may have spread to neighboring districts,
such as Shian and Youngam