CRAXBEKRY DISEASES OIS T THE PACIFIC COAST 15 
The final Bordeaux spray, applied on most of the bogs in this section 
about the first of August in 1923, remained adherent to the vines and 
berries so persistently that in many cases pickers objected to harvest- 
ing them. This fact, in conjunction with the observation that the 
final spray in itself apparently had little value, led to an alteration 
in the subsequent recommendations given the growers. The new 
program called for only two applications of Bordeaux mixture, one 
at the hook stage, the other immediately after blossoming. 
Meanwhile further experiments were performed to procure additional 
data on the adequacy of the schedule recommended, with the results 
shown in Tables 8 and 9. 
The tests in both 1924 and 1925 clearly demonstrated that the 
new schedule was justified. There was a sharp increase in the 
percentage of rot developing in berries from plots not receiving 
the hook-stage spray compared with those from all plots which had 
received it, this being more striking in 1924 than in 1925. Berries 
receiving both preblossom and after-blossom applications uniformly 
held up in storage practically as well as those receiving the additional 
third spray. Every lot which had received two applications of 
Bordeaux mixture in 1924 was in good marketable condition after 
three weeks of storage, with the possible exception of the Searls vari- 
ety. In the 1925 tests the berries were in transit for 3J^ weeks, dur- 
ing which time the twice-sprayed lots developed from 2 to 6 per cent 
of rot, while the berries from plots not receiving the hook-stage spray 
showed a higher percentage, ranging up to 14 per cent in Bennett plots. 
After an additional storage period of one month 11 per cent was 
the highest proportion of rot found in any standard-sprayed lot, 
whereas many of the lots originating from plots receiving no hook- 
stage spray had more than 20 per cent of rotted berries. The supe- 
rior keeping quality of the former group became even more pronounced 
as the storage period was increased. In other words, the hook-stage 
and after-blossom applications of Bordeaux mixture controlled storage 
rots satisfactorily under conditions as severe as commercial berries 
are ever subjected to in a well-regulated marketing system., whereas 
in many cases berries produced and handled under conditions 
identical in all respects except that of being differently sprayed 
rotted so badly as to be unmarketable. 
DISCUSSION OF SPRAYING EXPERIMENTS 
Before drawing definite conclusions from this series of spraying 
experiments it may be well to point out certain factors which may 
have some bearing upon the results, 
In the first place, it is not to be expected that the proportion of 
infected berries will be equally and uniformly present throughout 
any considerable bog area, as is well illustrated in the extreme case 
of Sclerotinia rot. This disease usually appears in isolated spots in a 
bog where most of the berries may be infected, while it is entirely 
absent over the remainder of the area. A similar condition, though 
less marked, undoubtedly holds true of other rots. Local influences 
also must play an important part in determining the number of berries 
infected, such as depth of vine and elevation of the bog above the 
water table. For example, in the McFarlin tests of 1925 (Table 9) 
the last two plots recorded in the last two columns were located on 
