Efficacy of different clearing saw methods in biological sprout control in birch (Betula pendula [roth] and B. pubescens [Ehrh.]) compared to manual and mechanized application

Role and function of Chondrostereum purpureum in biocontrol of trees

“…The consumption of inoculum has been high with all studied devices (Laine et al 2020b). In future, the accuracy of spreading mechanisms should be improved in order to get the consumption of inoculum on an economically sound level.…”

“…In recent years, some practical scale experiments for spreading inoculum with clearing saws and devices installed on forest machines have been conducted (Laine et al 2019(Laine et al , 2020a. In motor-manual work, different kinds of nozzle solutions connected to clearing saw blades have been tested (Laine et al 2020b), and in mechanized PCT-work, a UW40cleaning head installed on a Tehojätkä mini-harvester (Usewood Forest Tec LTD) and Mense cutting head installed on a normal harvester have been tested (Laine et al 2019(Laine et al , 2020a. According to these studies, the efficacy of the biological control was not as high as in manual application experiments.…”

“…20-40% of birch stumps died after the fungal treatment. The lack of reliability and accuracy of spreading mechanisms in both motormanual and mechanized devices were the main reasons for low success rates (Laine et al 2019(Laine et al , 2020b. In some cases, the stumps were also too tall after mechanized PCT-work, and therefore they continued to grow from branches.…”

“…Difficulties in getting to market are probably not in the production lines nor in the efficacy of the treatment agent, as the fungus grows well on artificial media and is excellent in controlling the sprouting of the target tree species (see above). Instead, the major dilemma is the lack of cost-efficient treatment protocols for large-scale usage (Laine et al 2020b ).…”

“…In order to solve this, both purely mechanical solutions where collecting aligns the stump surfaces with the face of the treatment nozzle and more advanced technology using, e.g., artificial vision and intelligence to recognize and individually treat each stump surface can be imagined. In both cases, the additional time consumption of the treatment should be minimized (Laine et al 2020b ).…”