Sledování karanténního organismu Dothistroma septosporum na okrasných dřevinách v Arboretu Řícmanice

The aim of the work is evaluation of the overall level infestation of coniferous trees in the arboretum, including identification of the pathogen sporulation, depending on climatic data, evaluation of the present state in the castle park Průhonice, control the occurrence of quarantine organism D. septosporum and his impact on the current composition of tree species. The following topic of Bachelor work observe red needle blight of pines spoluration (D. septosporum) in the Arboretum Řícmanice. Monitoring was carried out continually from the late May towards to the late November 2010. In the Arboretum Řícmanice this pathogen was confirmed on 31 individuals hosts. From the monitored species are the most strongly damaged Pinus aristata, Pinus nigra, Pinus mugo and Pinus heldreichii by the needle blight quarantine. In the opposite, incidence of the pathogen was not confirmed on scots pine (Pinus sylvestris) and larch (Larix spp.). It has been proved, that the needle blight quarantine of pines are the biggest threat for the youngest and recently planted coniferous trees approximately to the 20 years of age. This fact plays a large role for the replacement trees in the composition of the arboretum, which will be affected by the replacement of existing host species of D. septosporum for the resistant species to this pathogen, or deciduous amenity trees, whose number may increase at the expense of coniferous trees in the future. On the model area of castle park Průhonice, was not confirmed strong presence of D. septosporum. The pathogen is occured in the park but in a such small extent, that it cannot affect the original compositional scheme of the park. Besides the D. septosporum are in the park similar symptoms on the tree species caused by the other diseases of the assimilation apparatus Cyclaneusma spp. and Lophodermium spp.