First observations on disease development of Marssonina coronaria o apple in Lake Constance area

摘要

The problem of early leaf fall on apple caused by Marssonina coronaria was approache by temporarily covering trees of the cultivar 'Topaz' with a membrane rain cover to inhibi, the spread of conidiospores. Different time periods of coverage during thesumme seasons of 2012-2014 were compared with regard to the resulting level of infestation a harvest time. A time frame from roughly mid June to the end of August was identified to b the most important period to decelerate the spread of the disease. Theresults of an initia trial with customary organic plant protection treatments in different periods in 2013 and th$ continuous recording of the disease development in 2012-2015 supported this finding.