Primary Study On Production And Release Of The Conidia Of Botryosphaeria Berengeriana De Not.f.Sp. Piricola On Apple Branches

The apple ring rot distributes wildly in china. More than 300 samples of Botryosphaeria berengeriana de Not. f. sp. piricola on apple stems and fruit from Liao-ning, Yun-nan, and Hebei provinces were collected. The counties and cities in Hebei province include Bao-ding, Tang-shan, Lang-fang, Ding-zhou, Han-dan, Heng-shui, Shi-jiazhuang et al. A series of methods for generating conidia of Botryosphaeria berengeriana de Not. f. sp. piricola were tested. The results showed that ABA was the best medium for the formation and ripening of the conidia. PSA was the second most suitable media. The method to inoculate young apple fruit to generate conidia of Botryosphaeria berengeriana de Not. f. sp. piricola is also very convenient.The spore release of Botryosphaeria berengeriana de Not. f. sp. piricola on apple branches during the whole growing seasons in 2008 and 2009 was systematically surveyed and observed. The weather data during the growing seasons were recorded and analyzed. The results showed that the first time of the conidia of Botryosphaeria berengeriana de Not. f. sp. piricola massive occurrence needs suitable temperature and rainfall. The duration time of the rainfall is the dominant factor for the conidia release. The main transmission way of Botryosphaeria berengeriana de Not. f. sp. piricola on apple branches is by the splash of the rainwater. During one growing season the conidia of Botryosphaeria berengeriana de Not. f. sp. piricola can release for several times.By means of microscope observing, few conidia were found in the pycnidium from the end of November to the beginning of March. Ripen conidia were formed at the beginning of March. The peak time for producing large amount of conidia was from June to the beginning of September.