Determination of distribution and intensity of Heterobasidion annosum ( Fr. ) Bref. at pure and mixed fir stands in the directorate of Sinop Forest Management

In this study, the density and distribution of Annosum root rot disease were determined in different types of stands belonging to Turkish fir (Abies nordmanniana bornmülleriana Mattf.) that distrubutes within the borders of Sinop Forestry Directorate. In this context, the areas where the selection, maintenance and extraordinary revenue segments of Uludağ fir were made were determined, and discs were taken from the trees in the areas that differed in terms of pure and mixed forest establishments. As a result, disease was found at 72 samples of a total of 80 discs. The disease intensity in the study area is 90%, the average disc area covered by Heterobasidion annosum s.l. conidias was calculated as 8.62%. With respect to the distinction of the places where the colonization is observed (heartwood or sapwood), 32 (40%) of the examined discs, H. anosum s.l. colonization has been detected in the heartwood. The sample area where the disease intensity is lowest is Sample Area 4 with fir + beech + Scots pine mixed stand. In this study area, disease intensity was found 75% and the rate of heartwood infection was found only 5%. It is understood that most of the infections in this area (70%) were caused by airborne spores.