Effect of Scots Pine (Pinus sylvestris L.) Stand Thinning on Suppressiveness of soil to Heterobasidion annosum (Fr.) Bref. : Root and Butt Rots

Uppsala

International Union of Forest Research Organizations, Swedish University of Agricultural Sciences

1994

S. 624-632

10 Lit. Ang.

Bandaufführung

73808

In a Scots pine stand, age 16, two different thicket thinning procedures were applied in 1987. In part I of the stand every 7th row of trees and "wolf" trees were taken away. In part II only "wolf" trees were taken away. In 1992, when the stand was 21, soil samples were taken from both parts and isolation of soil fungi was performed. The communities of fungi obtained were subsequently examined for their suppressiveness to Heterobasidion annosum. The community of soil fungi from part I (intensively thinned) had a remarkable suppressive effect on Heterobasidion annosum, while the community from part II (routine thinning) was practicaly neutral to the pathogen. It seems that intensive thinning contributed to creating conditions in the soil unfavourable to Heterobasidion annosum, and should be considered as a biocontrol measure against the pathogen in young Scots pine stands.