16 
BULLETIN 550, U. S. DEPARTMENT OF AGBICULTUBE. 
Table 5. — Spray mixtures used, methods and dates of application, and percentages of in- 
festation in experimental plats, Phillips vineyard, North East, Pa., 1914. 
Dates sprayed 
with set nozzles. 
Dates 
sprayed 
with 
trailers. 
Ar- 
senate 
of lead 
(paste). 
Bordeaux mixture. 
Laun- 
dry 
soap. 
Nico- 
tine 
sul- 
phate. 
Water. 
In- 
Plat No. 
Lime. 
Copper 
sulphate. 
festa- 
tion. 
I 
June 12, 26, and 
July 12 . . . 
Lbs. Pounds. 
3 3 
3 3 
3 3 
Pounds. 
3 
3 
3 
Pounds. 
Pints. 
Galls. 
50 
50 
50 
Per ct 
5 2 
H 
June 26 and July 
12 ' 
4 5 
Ill 
June 26 ! July 12 
7.2 
Check A. ! 
S 7 
IV 
June 26 and July 1 
12 ' 
3 3 
3 3 
3 3 
3 
3 
3 
i 1 
1 1 
1 1 
i i 
50 
50 
50 
9 5 
V 
VI 
Check B. 
June 26 July 12 
June 26 July 12 
5. 5 
17.9 
52 4 
1 i 
1 
i 
j^-^sr 
s 
IT 
2ZT 
A 
IF" 
JT 
izr 
1 
8 
1 
d&tsr 
1 Last application only. 
The infestation in this vineyard had been very heavy the previous 
season, but in 1914 it was light. Check plat B was much more heavily 
infested than the ad- 
A/o/?r// jacent sprayed plat, 
whereas this plat was 
much more heavily 
infested than check 
plat A. While it is 
probable that spray- 
ing did reduce the in- 
festation somewhat in 
this plat and in the 
one next to it, be- 
cause of the wide va- 
riation of infestation 
in the unsprayed 
checks, this can not be stated definitely. The similarity of results 
in check plat A and the sprayed plats adjoining it indicates failure in 
control. 
Spraying Experiments in 1915. 
The season of 1915 was marked by extremely heavy rainfall during 
the spraying season and during the month following. Spraying- 
operations were interrupted frequently or delayed by rain and as a 
result spraying as a remedial measure was put to a very severe test. 
However, when the final counts were made, all plats sprayed with 
solutions containing arsenate of lead and soap and applied with 
"trailers" showed a satisfactory reduction of infestation from a com- 
mercial standpoint. The contrast in infestation between the sprayed 
plats and others was commented on with astonishment at harvest 
time by pickers who were ignorant that any remedial measures had 
Fig. 2.— Diagram showing arrangement of experimental plats in Mr. M. 
D. Phillip's yineyard, North East, Pa., 1914. Sprayed plats are 
marked with Roman numerals, check plats with letters. (Original.) 
