Bacterial canker of plum trees, caused by Pseudomonas syringae pathovars, as a serious threat for plum production in the Netherlands.

In the Netherlands, bacterial canker in plum trees (Prunus domestica) is a serious and recent problem in plum production. It is caused by Pseudomonas syringae pathovars syringae and morsprunorum. The trunks of the affected plum trees are girdled by bacterial cankers resulting in sudden death of infected trees in 3-4 years after planting. Disease incidences can be very high, and sometimes complete orchards have to be removed. Recently, plum cultivation in the Netherlands has changed from a relatively extensive into an intensive cultivation. However, due to the risks of losses of trees due to bacterial canker, growers are reluctant to plant new plum orchards. In general nurseries and fruit growers are not familiar with bacterial diseases and lack knowledge in order to prevent infections. Therefore, control strategies to manage plum decline have to be developed.