Current issue: 55(3)
Under compilation: 55(4)
The article presents six fasciations found in Finland on bird cherry trees. Based on the literature it seems that fasciations are the precondition for witches’ brooms. The witches’ brooms on bird cherry trees are rare, but they have been mentioned in literature. Some views on their occurrence and development are represented. Also the possible causes behind the developments are discussed based on literature.
The PDF contains a summary in Finnish.
Witches' brooms of Scots pine (Pinus sylvestris L.) have been suggested to be genetic rather than caused by bacteria. Seeds were collected from cones growing in Scots pine witches' brooms. More than half (43) of the 84 seedlings grown from the seeds were stunted and resembled witches' broom. The growth of the normal and witches' broom like seedlings were compared. When the seedlings were 8 years old, the normal seedlings were in average 37 cm and the witches' broom like seedlings 8 cm high. The result supports the theory that the witches' broom like growth was inherited in the Scots pine seedlings.
The PDF includes a summary in German.