Sprout control using a natural decay fungus

Challenge

In forest regeneration areas, naturally grown deciduous trees are usually abundant, restricting the growth of cultivated conifers. Therefore, deciduous trees are usually cut to provide better growing conditions for more valuable conifers. However, deciduous trees re-sprout quickly, and thus, additional thinnings of deciduous tree saplings are usually needed. In Finnish forests, altogether 56 million euros are used for sprout control annually.

Solution

Luke has an efficient method to restrict the growth unwanted deciduous trees. The method is based on a decay fungus, Chondrostereum purpureum, that naturally decays wounded deciduous trees. Unwanted deciduous saplings are cut, and fungal inoculum is spread on freshly cut stumps. From stump surface, the fungus grows within a stump and start to decay it. At Luke, we have developed a fungal strain of C. purpureum that can efficiently decay cut stumps and prevent re-sprouting.

Benefits

Ca. 80-100% of silver and downy birches (Betula pendula and B. pubescens), European aspens (Populus tremula) and grey alders (Alnus incana) do not sprout two to three growing seasons after the fungal treatment. In rowan (Sorbus aucuparia), the efficacy has been slightly lower, ca. 50%. Since re-sprouting is restricted, additional removal of deciduous saplings is not needed, and therefore costs for young forest management can be reduced.

IPR status

Luke has crossbred an effective isolate of the fungus Chondrostereum purpureum by isolating C. purpureum strains. An Isolate is stored in official and maintained fungal collections.