DISEASES OF APPLES ON THE MARKET. 
ANALYSIS OF DATA. 
Summary Tables 1 and 2 bring out several interesting facts, the 
most striking of which is that in the crops of 1918, 1919, and 1920, 
both barrel and box, blue-mold rot was more common and occurred 
in a larger proportion of the cars examined than any other disease. 
In both the barrel and the box crop for 1917 the most common dis- 
ease noted was "decay." The service was new, and the inspectors prob- 
ably di'd not feel themselves experienced enough to distinguish the 
different rots. To be on the safe side they called most rots " decay." 
These tables also show that next to blue-mold rot and decay the 
most common disease in the box crop was scald; in the barrel crop, 
black-rot, with scald ranking fourth. In the box crop, during the 
four years, there were 3,674 cars that showed disease, of which 
number 2,954 showed blue-mold rot, 219 decay, and 1,191 scald. In 
the barrel crop, out of 1,548 cars snowing disease 997 showed blue- 
mold rot, 310 decay, 243 black-rot, and 208 scald. 
Diseases common to both crops were blue-mold rot, decay, scald, 
Alternaria rot, scab, soft scald, bitter-pit, and internal breakdown. 
Diseases reported in the box crop only were anthracnose, Jonathan 
spot, water-core, and drought-spot; in the barrel crop only were 
black-rot, brown-rot, bitter-rot, Khizopus rot, pink-mold rot, gray- 
mold rot, blotch, rust, fruit-spot, and sooty blotch. Total diseases 
reported for the box crop, 12; for the barrel crop, 18. 
The term anthracnose as used in this bulletin applies to the true 
anthracnose found in the humid apple districts of Oregon and Wash- 
ington and also to an anthracnoselike rot found in a considerable 
number of cars from the irrigated apple districts of Washington 
during the late winter and spring of 1921. 
BOX CROP: DISEASE BY YEARS. 
Figures for single diseases by years are given in Table 1, but the 
general condition of the crop as affected by all diseases is better 
shown in Table 3. 
From Table 1 it appears that in the cars which showed disease, 
the disease index was greatest in 1917 and least in 1919, with an 
average for the four years of 12.6. From 1918 to 1920 the per- 
centage of rot decreased by three-fifths and the percentage of scald 
quadrupled. During the same period there was a ninefold increase 
in other diseases, although the percentage of these was not large at 
any time — that is, when calculated on the basis of all cars showing 
disease. When calculated on the basis of cars showing a particular 
disease, the percentage for some of these diseases is quite high. For 
example, the average percentage of water-core in 47 cars (Table 1) 
was 19.6; of internal breakdown in 81 cars, 13.5. 
Table 1. — Summary, box crop, all years and all diseases. 
Year. 
Total 
cars. 
Blue-mold 
rot. 
Decay. 
Scald. 
Anthrac- 
nose. 
Alternaria 
rot. 
Jonathan 
spot. 
Cars. 
Per 
cent. 
Cars. 
Per 
cent. 
Cars. 
Per 
cent. 
Cars. 
Per 
cent. 
Cars. 
Per 
cent. 
Cars. 
Per 
cent. 
1917 
233 
219 
2,084 
1,138 
62 
162 
1,963 
767 
7.5 
13.0 
7.6 
6.0 
150 
40 
19 
10 
10.4 
8.1 
5.8 
4.3 
98 
31 
425 
637 
19.0 
13.1 
17.6 
13.8 
10 
15.0 
1918 
2 
23 
98 
14.0 
2.7 
6.8 
1919 
1920.. 
20 
17 
7.6 
4.5 
3 
15 
12.3 
12.0 
Total or average... 
3,674 
2,954 
7.5 
219 
9.3 
1,191 
15.6 
123 
6.0 
37 
6.2 
28 
13.1 
