This is the most dangerous plum tree diseases as it produces a lot of damage to the crop and it affects a lot of European countries.
The attack can be seen on the leaves and fruits of the plum trees, which belong to sensitive plum species.
On the leaves that have been fully developed, light-green or yellow stains emerge and these are circular, or semi-circular shaped and evenly spread on the entire surface on the limb.
The symptoms can be visible in May-June and in September-October. During warm summer days, the symptoms cannot be seen, only rarely on leaves which are located in shady places. 3-4 weeks prior to the maturing process, circular or elongated stains emerge on the surface of the sensitive fruits and these stains are yellow to green and with a watery aspect. Next to these stains, the mesocarp of he fruits turns red or violet and gains a gummy consistency.
The Plum pox virus affects other fruit bearing trees, such as the peach tree, apricot tree, Armenian plum and the cherry plum.
The virus is transmitted through the infected sowing material and it is spread through aphids and cicadas.
Prevention and control
We recommend using healthy grafting and rootstock, planting healthy seedlings, cultivating resilient species and chemically preventing carrying insects.
As a prevention method, we recommend using the thermo-therapy – keeping the young seedlings for 2 weeks in temperatures of 37 degrees Celsius, followed by grafting their tips with healthy rootstock.