Über die 1959 erstmalig in Deutschland aufgetretene Peronospora-Krankheit des Tabaks

Downy mildew on tobacco caused by Peronospora tabacina Adam was observed for the first time in Germany during the ·summer of 1959. The first outbreak occurred in the northwest of the eountry, but later on the disease was found in the middle and in the southwest. In most tobaeeo growing areas brown lesions appeared on the leaves of nearly mature plants of all commercial varieties. The market value of the yield was diminished. Tobacco plants cultivated for experimental purposes in glasshouses were also infected and mostly killed. A survey is given about the praetical knowledges of this essential trouble in the United States and Australia. Control measures based on these experienees are recommended.