Apr. 15, 1914 
Experiments with Apple Leaf-Spot Fungi 
65 
In some of the series of experiments the branches were removed from 
under bell jars for an hour every other day and the leaves allowed to 
dry. In such cases there seemed to be a rough relation between the 
number of such periods and the number of zones. 
In one orchard in Virginia the leaves of eight York Imperial apple 
trees had been badly spotted through injury by sprays. Later, these 
spots enlarged and became typical frog-eye spots. Cultures made 
from these enlargements with the same precautions as previously out¬ 
lined developed Alternaria in practically every case. 
CONCLUSIONS 
From these experiments one is justified in concluding that under certain 
conditions Alternaria mali is able to enlarge dead spots of apple leaves 
and may be classed as a rather strong facultative parasite. Coniothy- 
Hum pirinum possesses but little power of enlarging dead areas and may 
be classed as a saprophyte or at best as a weak facultative parasite. 
Coryneum foliicolum, Phyllosticta limiiata , Monochaetia mali , and Phomop- 
sis mali are, in so far as apple leaves are concerned, purely saprophytic. 
LITERATURE CITED 
Brooks, Charles, and DeMeritt, Margaret. 
1912. Apple leaf spot. Phytopathology, v. 2, no. 5, p. 181-190. 
Crabill, C. H. 
1913. Studies on Phyllosticta and Coniothyrium occurring on apple foliage. 
Va. Agr. Expt. Sta. Rpt. 1911-12, p. 95-115. 
Hartley, C. P. 
1908. Some apple leaf-spot fungi. Science, n. s., v. 28, no. 709, p. 157-159. 
Lewis, C. E. 
1909. Apple diseases caused by Coryneum foliicolum Fckl. and Phoma mali 
Schulz et Sacc. Maine Agr. Expt. Sta. Bui. 170, p. 185-200. 
1912. Inoculation experiments with fungi associated with apple leaf spot and 
canker. Phytopathology, v. 2, no. 2, p. 49-62. 
Scott, W. M., and Rorer, J. B. 
1907. Apple leaf spot caused by Sphaeropsis malorum. U. S. Dept. Agr., Bur. 
Plant Indus. Bui. 121, p. 47-54. 
Sheldon, J. L. 
1907. The taxonomy of a leaf-spot fungus of the apple and other fruit-trees. 
Torreya, v.7, no. 7, p. 142-143. 
1908. Another leaf-spot fungus of the apple. Torreya, v. 8, no. 6, p. 139-141. 
