EN
The aim of performed studies was to monitored the occurrence of airborne spores of the fungi Alternaria solani and Alternaria alternata depending on weather conditions on potato fields, at three localities (Bonin, Mierzym, Przytocko) during two vegetative seasons in 2008–2009. The monitoring of spores was performed using glass spore traps. The highest concentation of spores in the air was recorded at air temperature not exceding 18°C with relative humidity above 80% for A. solani and 70–75% for A. alternata. The amount of rainfall diversified the number of recorded spores. The intensity of spore occurrence of A. solani was related to a higher amount of rainfall, followed by rainless periods, while a lower amount of rain with uneven distribution favoured the fungus A. alternata.