10 
BULLETIN 1253, U. S. DEPARTMENT OF AGRICULTURE. 
Table 6. — Percentage of blue-mold rot in box and barrel crops, calculated on tht 
basis of cars showing blue-mold rot, by months, 1917 to 1920. 
Month. 
Box crop. 
Barrel crop. 
Cars. 
Per cent. 
Cars. 
Per cent. 
July 
18 
49 
71 
131 
161 
111 
97 
126 
103 
60 
40 
10 
9 6 
August . . ... 
2 
1.5 
4 
September 
8 9 
October. . . . . . 
82 
184 
277 
278 
376 
663 
489 
409 
194 
4.1 
5.6 
5.5 
6.0 
7.4 
7.6 
8.9 
9.0 
8.5 
8 5 
November . ... 
8 1 
December. ... 
4.9 
January .. .. 
7 6 
February .. _ _ ... .. .... 
8 
March ._ .. . . . 
8 3 
April .. . .. ... . 
12 5 
May . . . . 
15.6 
June 
16 5 
Total or average . 
2,954 
7.5 
977 
8 3 
The box crop showed a fairly uniform rate of increase in the percent- 
ages of rot, of blue-mold rot considered alone (see Table 6 and fig. 3), 
and of disease index from October till June; the barrel crop only from 
December till June. It is noteworthy, however, that the percentage of 
blue-mold rot increased much more regularly throughout the season 
in the box crop than it did in the barrel crop. The difference is prob- 
ably due to the much larger proportion of summer and fall varieties 
in the barrel crop (8.3 per cent of all cars inspected) during the 
early part of the season; that is, until January 1. Such varieties 
are marketed more often directly from the orchard or from common 
storage than from cold storage and consequently show great varia- 
tion in condition. Early varieties appear in the box crop, but 
in actual carloads shipped they make up only a small proportion 
(less than 3 per cent) of the total cars inspected. 
BOX CROP: DISEASE BY VARIETIES. 
The principal thing to be noted here is that the percentages of 
rots and scald and the disease index (Table 7) are smallest for varieties 
ordinarily not stored at all and that these figures are successively 
larger for short-storage and for long-storage varieties. The per- 
centage of " other diseases" decreases with the length of storage. 
Table 7. — Summary , box crop, by varieties, 1917 to 1920. 
Variety. 
Total 
cars. 
Rots. 
Scald. 
Other 
diseases. 
Disease 
index. 1 
Varieties usually not stored at all: 
2 
3 
. Per cent. 
1.0 
1.0 
Per cent. 
Per cent. 
2.5 
4.0 
3.5 
5.0 
5 
1.0 
3.4 
4.4 
Short-storage varieties: 
4 
257 
5 
6 
1 
10 
2 
9 
3.2 
5.2 
5.6 
1.5 
6.0 
4.6 
1.0 
4.8 
31.7 
( 2 ) 
2.5 
3.0 
37.5 
Jonathan.. - 
8.4 
5.6 
Mcintosh 
( 2 ) 
1.0 
2.8 
6. 
8.9 
7.5 
( 2 ) 
1.4 
14.9 
8.6 
1.1 
& 
294 
5. 1 
2.8 
8.8 
» See footoote to Table 3. 
2 Less than 1 percent. 
