8 THE CONTROL OF APPLE BITTER-ROT. 
find as much as 50 per cent of the fruit of this variety harvested in 
good condition was exceptional. The Yellow Newtown growers of this 
section had had a similar experience with the crops of 1901 and 1899 
(two and four years previous), and some were on the point of abandon- 
ing their orchards in despair, one man going so far as to cut down his 
trees. It seemed, therefore, especially desirable for. the Bureau to 
determine the best methods for combating this disease and to obtain 
data upon which definite recommendations could be based. Accord- 
ingly a series of experiments was planned, which were carried out in 
the orchards of Mr. W. H. Goodwin, at Avon, Va., to whom the 
Department is much indebted for valuable services in facilitating the 
work. The work was outlined and some spraying done in the spring 
of 1904, but this being the ‘‘off year” it soon developed that there 
would be no crop of apples in that section, and the actual work reported 
upon in this paper was not commenced until the spring of 1905. 
THE DISEASE AND ITS CAUSE. 
A detailed account of the disease and the fungus causing it having 
appeared in a previous bulletin of this Bureau,“ many details will be 
omitted in the following discussion, the attempt being made to include 
only those facts with special bearing on the subject of this paper. 
THE DISEASED SPOTS ON THE APPLE. 
The diseased spots are usually a quarter to a half inch in diameter 
before the fruit grower ordinarily notices them, but they first appear 
as very small, yellowish-brown, sometimes watery specks, frequently 
bordered with a ring of purple-red. The purplish margin is especially 
prominent on spots that are retarded by cool weather, and many late 
infections appear only as red or purplish specks, never developing 
farther on account of adverse conditions. On the other hand, the 
purplish coloration is likely to be entirely absent from a spot that is 
developing rapidly under favorable conditions. As the spot enlarges 
and grows older it becomes dark-brown in the center, shading off into 
a light watery margin. It is circular in outline, with a well-defined 
margin, and soon becomes sunken. (See Pl. I, and Pl. VI, fig. 1.) 
When the spots are about one-half inch in diameter, fruiting pus- 
tules begin to appear in the form of small black dots slightly raised 
and usually arranged in concentric rings (Pl. VI, fig. 1). These pus- 
tules soon break through the skin (Pl. II, 6), discharging pink, sticky 
spore masses, which are readily washed off by dews and rams. As 
the disease progresses, other rings of pustules appear and give forth 
spores in great abundance. When the pink spore masses are washed 
away the pustules appear as black ragged openings through the skin of 
«Von Schrenk and Spaulding, 1. c. 
