Study of the non-vector spread of the pine nematode Bursaphelenchus xylophilus through sawdust

The goal of the study was to assess the possibility of Pinus sylvestris trees to be infested with pinewood nematode B. xylophilus through PWN-infested sawdust. The trials were conducted in climatic room at a temperature of 26℃ and at humidity of 60-70% from June to October, 2020. Each trial included 4-year-old seedlings of 12 Pinus sylvestris pines.

The experiment contained seven trials, including the control: 1) uninjured stem + PWN-infested sawdust, 2) injured stem + PWN-infested sawdust, 3) injured stem + PWN-infested sawdust is 2.5 cm from the stem, 4) uninjured roots + PWN-infested sawdust in soil, 5) injured roots + PWN-infested sawdust in soil, 6) injured roots without sawdust, and 7) control. At the end of the experiment, the number of pinewood nematodes in the stem and roots of infested seedlings was counted. The number of nematodes is based on 100 grams wet weight of woody substrate and 100 cm3 for soil substrate. We counted the number of wilted pine seedlings taking into account wilt classes (from 0 to 5) in different trials at the 20th week of the experiment.