For a number of years the writer has made some observations on a disease of the plum and cherry which has received the common name of Scab. (Cladosporium carpophilum Von Thuemen). My attention was first attracted to this disease in the fall of 1889 when many varieties of Prunus americana suffered severely. It has been noted on this species every year since, with the exception of 1892 when the plum crop on the college grounds was a failure. In 1891 and 1892 it occured on such varieties of Prunus cerasus as Cerise d’Ostheim, Spate Amarelle, Shadow Amarelle and Wagner. The assistant Mr. F. O. Stewart was detailed in 1892 to make observations, on different varieties and as a result of his work he reports that Schatten Amarelle, Shadow Amarelle, Spate Amarelle and Lutovka are affected. This list as is known consists chiefly of Russian varieties. As the orchards on the college consist entirely of this class of fruit it is hard to conjecture what other varieties would have done when grown in similar situations. I may state, however, that the Early Richmond growing not far from the college grounds has escaped this trouble entirely. Late and Early Richmond grown in the village of Ames as well as some Russian varieties were also exempt.
Pammel, L. H.
"Notes on a few common fungus diseases.,"
Bulletin: Vol. 2
, Article 6.
Available at: https://lib.dr.iastate.edu/bulletin/vol2/iss23/6