Spread of the invasive pathogen Lecanosticta acicola on species of Pinus in Bulgaria

Abstract

The brown spot needle blight, caused by the fungal pathogen Lecanosticta acicola , has been the most serious and damaging disease on needles of Pinus spp. in recent years. In Bulgaria, the pathogen was reported for the first time in 2017 in a generative plantation of Pinus sylvestris in the region of the State Forestry Ardino, the Eastern Rhodopes. The newly- established invasive pathogen is considered highly adaptable to new hosts and environmental conditions. The life cycle and symptoms of the disease strongly suggest that the new emerging pathogen has the potential to cause severe damages and is a serious threat to naturally distributed species of Pinus in the country. In the period 2018-2019, a spread of L. acicola from the initial outbreak was established throughout stands of P. sylvestris and P. nigra on the territory of Kardzhali District.