DISEASES OF APPLES OX THE MAEKET. 
Other diseases, — For other diseases than rots and scald, the average 
after January was less than 1 per cent. The disease index increased 
from October until June, but not so regularly as did the percentage 
of rots alone. 
BARREL CROP: DISEASE BY MONTHS. 
Rots. — The figures in Table 5 (see also fig. 2) show an irregular 
condition from July to December, inclusive; they were lowest in 
December and increased steadily from then on until June. 
Table 5.— Summary, barrel crop, by months, 1917 to 1920. 
Month. 
Total, 
cars. 
Rots. 
Scald. 
Other 
diseases. 
Disease 
index. 1 
Per cent. 
Per cent. 
Per cent. 
49 
86 
11.3 
7.0 
2.4 
( 2 ) 
13.9 
7.9 
151 
223 
244 
12.0 
13.7 
11.3 
1.6 
( 2 ) 
1.1 
13.6 
14.1 
12.9 
144 
5.4 
( 2 ) 
1.8 
8.0 
139 
9.0 
4.9 
3.6 
17.7 
179 
9.3 
9.5 
1.6 
20.5 
172 
9.2 
15.4 
3.6 
28.3 
84 
12.9 
11.2 
2.6 
26.7 
63 
14.5 
8.8 
2.6 
25.9 
14 
17.0 
5.0 
1.2 
23.2' 
1,548 
10.5 
4.3 
1.9 
16.8 
July 
August 
September. 
October 
November. 
December. 
January. .. 
February. . 
March 
April 
May 
June 
Total or average. 
See footnote to Table 3. 
2 Less than 1 per cent. 
Scald. — Scald first appeared in December, was found in the largest 
number of cars in February, and in the highest (average) percentage 
in March. The percentages decreased both ways from that point. 
Other diseases. — The percentages ran fairly uniform throughout 
the year and were low at all times. 
PER CENT 
BLUE MOLD 
ROT 
i 6 
12 
■ 
Bar 
re/ C 
-op 
f ^ + * 
-H 
M 
^c 
-J^ 
^~ 
>' 
..''1^ 
' Box C 
/ 1 
nop 
O Q_ 
() 
Z 
CD 
or 
UJ 
< 
UJ 
< 
Q 
-} 
Ll. 
^ 
Fig. 3.— Percentages of blue-mold rot in the box and barrel crops, by months, for the four crop years, 1917 
to 1920, inclusive. The percentages are calculated on the basis of all cars showing blue-mold rot. 
Disease indices. — These take the same general course as that shown 
by the rots, with an irregular condition for the first six months, a 
minimum in December, and larger indices from then on, although 
the maximum, because of adding the scald figures, came in March 
instead of in June. 
90579°— 24f 2 
