18 
BULLETIN 550, IT. S. DEPARTMENT OF AGRICULTURE. 
On all sprayed plats where poison with adhesive had been applied 
with " trailers" the control was effective. Plats I and II on which 
arsenate of lead (paste) had been applied at the rate of 3 pounds to 
50 gallons of liquid were infested more heavily than Plats III and IV, 
on which arsenate of lead at the rate of 5 pounds to 50 gallons had 
been applied. The infestation was naturally heavier on the west 
side, however, as is shown by a comparison of the unsprayed plats. 
Double spraying appeared to reduce the infestation but not enough 
to offset the extra cost of application. 
EXPERIMENT IN THE MILLER AND CARLBURG VINEYARD, NORTH EAST, PA., 1915. 
The experimental plat in this vineyard included 64 rows covering 
about 10 acres. It was divided into 10 plats of 6 rows each, the 
4 remaining rows being left for check. This plat was surrounded on 
£xsr 
B 
A/o/?rs/ 
J- 
2Z 
jzt 
J3T 
& 
£7 
JZZZ 
T777T 
ZT 
X 
/4 
*v£-sr 
c 
^sc 
■x/r 
A/ 
Fig. 4.— Diagram showing arrangement of experimental plats in the vineyard of Messrs. G. H. Miller and 
A. I. Carlburg, North East, Pa., 1915. The sprayed plats are marked with Roman numerals and the 
check plats with letters. ( Original. ) 
all sides by vineyard, two parts of which were used as checks also. 
The arrangement of plats is shown in the diagram (fig. 4). Spraying 
operations for both first and second applications in this vineyard 
were interrupted and delayed by frequent rains. 
Table 8. — Spray mixtures used and methods arid dates of application in experimental plats, 
Miller and Carlburg vineyard, North East, Pa., 1915. 
Dates of 
spraying. 
Arse- 
nate of 
lead 
(paste). 
Bordeaux mix- 
ture. 
Laun- 
dry 
soap. 
Fish- 
oil 
soap. 
Flour 
paste. 
Nico- 
tine 
sul- 
phate. 
Water. 
Method of ap- 
plication. 
flat No. 
Lime. 
Copper 
sul- 
phate. 
July 2, 15 
July 2, 15 
July 2, 15 
July 3, 16 
July 3, 16 
July 3, 16 
July 3, 17 
July 5, 17 
July 5, 17 
July 5, 17 
Pounds. 
3 
5 
3 
3 
3 
3 
3' 
3 
3 
Pounds. 
3 
3 
Pounds. 
3 
3 
Pounds. 
1 
Pounds. 
Pounds. 
Pints. 
Gallons. 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
"Trailers." 
II 
2 
2 
Do. 
mi 
Do. 
IV 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
3 
1 
i' 
l 
Do. 
v 
VI 
2 
1 
i 
Do. 
Do. 
VII 
Do. 
VIII 
2 
Do. 
IX 
Do. 
x 
2 
"Set nozzles." 
i Rain followed immediately after the second spray application on this plat and apparently washed off 
most of the spray. 
