Abstract
In spite of the successful application of chemical compounds (Maneb, Zineb) the aim to control the disease is the breeding of resistant varieties. We propose to select (phenotypically) resistant isolated plants, a method which has proved to be rather successful in the breeding of tobacco resistant to Y-virus. Until now we have selected the air-curing types SC 13 and SC 14 and the flue-curing types SCV 23 and SCV 26 from spontaneous as well as X-ray mutations, and we tested them on a larger scale for their resistance to PTA. As far as material was available a survey is given of the resistant types and different grading schemes are described