Inonotus obliquus is a pathogenic fungus––known as chaga in Asia and Russia and pakuri in Finland––that grows on broadleaves. Its sterile conks are used as an active ingredient in traditional healthcare products. Due to the higher value of pakuri than the tree it grows on, the cultivation of I. obliquus on living trees is expected to generate new and increased income opportunities for forest owners. So far, the success of large-scale inoculations of the fungus have not been studied. Therefore, the objectives of this study were to examine the probability of fungus infection and the appearance of sterile conks on birches, and to investigate the factors that affect the success of the inoculations. To this end, a total of 679 living birch trees (Betula pendula and B. pubescens) in 24 stands growing under different conditions in Finland were inoculated with two strains of I. obliquus, and re-examined after 4–5 years. The proportion of birches infected per stand was, on average, 79 ± 13%, whereas 6 ± 15% of birches per stand bore one or more conks. The size of the largest conk on a stem was, on average, 54 ± 64 cm³. Part of the infected trees (13% of all trees studied) also showed signs of bulging and/or cracked bark, indicating conk formation under the bark. The main factors that improved the probability of successful infection and the incidence of conk on birches were southerly location, mineral soil texture, low mean tree diameter, high stand basal area, and inoculation at the beginning of the thermal growing season. Also, the fungal strain used had a significant effect on the probability of infection and bulging. Despite successful inoculation, the formation of conks was found to be a slow process. Therefore, the cultivation of I. obliquus may be difficult to integrate into the management of commercial forests, although set-aside, low-productive birch, especially B. pubescens stands, can be recommended for utilization in its cultivation.

斜头inonotus是一种致病性真菌（在亚洲和俄罗斯被称为chaga，在芬兰被称为pakuri）在宽阔的叶子上生长。它的无菌浓缩液被用作传统保健产品中的活性成分。由于比它生长在树上pakuri价值较高，种植一斜上活着的树木，预计对森林的业主新增加收入的机会。迄今为止，尚未研究大规模接种真菌的成功。因此，本研究的目的是检查真菌感染的可能性和桦树上无菌结节的出现，并调查影响接种成功的因素。为此目的，共有679棵活白桦树（Betula pendula和B.毛竹）在24个矗立在芬兰的不同条件下使用的两种菌株接种在成长一个斜，经过45年重新审查。每个摊位的桦树受感染的比例平均为79±13％，而每个摊位的桦树中有6±15％会生一个或多个con。茎上最大的康克大小平均为54±64 cm ³。部分受感染的树木（占研究的所有树木的13％）也显示出鼓胀和/或破裂的树皮迹象，表明树皮下形成了树丛。改善成功感染的可能性和桦树上叮铃声的几率的主要因素是偏南的位置，矿质土壤质地，平均树直径低，林分基础面积高以及在热生长季节开始时进行接种。同样，所使用的真菌菌株对感染和鼓胀的可能性也有显着影响。尽管接种成功，但发现形成斑点的过程很缓慢。因此，尽管搁置了低产桦木，尤其是白僵菌，但斜纹梭菌的种植可能难以整合到商品林的管理中。 林分，建议在其栽培中加以利用。