84 EXPERIMENT STATION. [Jan. 



EXPERIMENTS RELATING TO THE CONTROL 

 OF POTATO SCAB. 



G. E. STONE AND G. H. CHAPMAN. 



Early ideas concerning the nature and cause of potato scab 

 in Europe and America varied quite widely, and the history 

 of the study of this disease and the discovery and isolation of 

 the specific organism causing it, together with the discovery of 

 measures for its control, afford a brilliant example of the effi- 

 ciency of modern pathological investigations. But it is not 

 our intent to give a detailed account of the history of this disease 

 as that has already been done by Dr. J. C. Arthur,^ Dr. J. E. 

 Humphrey," Dr. I\. Thaxter,^ and particularly Prof. H. L. 

 Bolley,"* who has given a very full bibliography of European 

 and American investigators. 



From the earliest times many theories have been advanced 

 by different observers relative to the cause of potato scab. 

 Some of these early investigators attribute the cause of the 

 disease to different organisms, while others associate the disease 

 with iiinuincra1)le factors, such as soil, moisture, etc. Dr. J. C, 

 Arthur ^ appears to have been the first American pathologist 

 to study the causes of potato scab. His early experiments were 

 to determine the influence of various factors which some of the 

 older observers regarded as having a bearing on the cause of 

 the disease. In co-operation with Dr. C. A. Goessmann, how- 

 ever. Dr. J. E. Humphrey was working on the disease along 

 the same lines at practically the same time, although his first 

 publication appeared later than that of Dr. Arthur. On Aug. 

 26, 1890, Prof. H. L. Bolley, then with the Purdue Agricul- 

 tural Experiment Station, Ind., read a paper before the Ameri- 



1 J. C. Arthur, 6th Ann. Rept. N. Y. (Geneva) Agr. Exp. Station, 1888, pp. 344-347. 



2 J. E. Humphrey, 6th Ann. Rcpt. Ma.ss. Exp, Station, 1888, pp. 131-130; also 7th Ann. Rept., 

 1889, pp. 214-223, and 8th Ann. Rept., 1890, pp. 216-230. 



3 R. Thaxter, Ann. Ropt. Conn. Agr. Exp. Station, 1890, pp. 81-95; also 1891, pp. 153-160. 

 * Agr. Soience, 1S90, Vol. IV.. pp. 243-256; also pp. 277-287. 



6 J. C. Arthur, Bui. 59, Purdue Univ. Agr. E.\p. Station, 1895. 



