Authors: Kurkela, Timo
Journal: Karstenia, Volume 37 (1997), Issue 1, pages 19-26.
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Key words: Neofabraea populi, Populus tremuloides, hybrid aspen, Populus x wettsteinii, Populus tremula x Populus tremuloides, spore dispersal, spore production, weather factors
Abstract: Ascospore production and discharge by Neojabraea populi on hybrid aspen (Populus x wettsteinii) was studied during two summers in Finland. The main spore production began in July and continued until mid-October. High spore counts were obtained in connection with occasional rain showers from July to September. In the daily data,amount of precipitation, relative humidity, and daily maximum amount of dew correlated positively with the number of spores. Spore release was usually induced by rain,often with several hours delay, as was clearly seen in the short-term hourly variation in the number of spores.