22 
BULLETIN o50, IT. R s DEPARTMENT OF AGRICULTURE. 
Table 12. — Spray mixtures used and method and dates of application in experimental 
plats, Bartlett vineyard, North East, Pa., 1916. 
Date, 
sprayed. 
Arsenate 
of lead 
(powder). 
Bordeaux mixture. 
Laundry 
soap. 
Resin 
fish-oil 
soap. 
Potash 
fish-oil 
soap. 
Water. 
Method 
Plat No. 
Lime. 
Copper 
sulphate. 
of appli- 
cation. 
I 
July 22 
Aug. 12 
Julv 6, 25 
July 6,25 
and Aug. 
12. 
July 5,21 
July 6,21 
July 5,21 
July 5,22 
Pounds. 
1* 
1* 
2i 
11 
1§ 
Pounds. 
3 
3 
3 
3 
3 
3 
Pounds. 
3 
3 
3 
3 
3 
3 
Pounds. 
1 
Pounds. 
Pounds. 
Gallons. 
50 
50 
50 
50 
50 
50 
50 
50 
" Trail- 
11 
1 
1 
ers." 
Do. 
Ill 
Do. 
IV 
1 
1 
1 
1 
Do. 
V 
Do. 
IV 
Do. 
VII 
Do. 
vni: 
3 
3 
2 
Do. 
Table 13. — Percentage of infestation in experimental plats, Bartlett vineyard, 
East, Pa., 1916. 
North 
Number 
of 
vines. 
Number 
of 
clusters. 
Total, 
berries. 
First brood. 
Second brood. 
Plat No 
Infested 
berries. 
Infesta- 
tion. 
Infested 
berries. 
Infesta- 
tion. 
Lower. 
I 
20 
20 
20 
20 
20 
20 
20 
20 
6 
20 
6 
20 
6 
532 
424 
415 
389 
390 
411 
460 
474 
111 
681 
200 
512 
214 
17,556 
12, 720 
12, 450 
11,281 
11, 700 
11, 508 
12, 420 
15, 168 
3,330 
18, 068 
7,200 
14, 336 
6,848 
1,708 
Per cent. 
9.72 
2,970 
2,486 
6,913 
243 
81 
182 
10, 909 
768 
3,158 
724 
6,380 
67 
1,764 
Per cent. 
16.92 
II 
19. 97 
Check A 
858 
228 
6.64 
2.02 
55. 53 
Ill 
2.14 
IV 
.68 
V 
145 
1.26 
1.57 
Check B 
79. 72 
Upper. 
VI 
320 
717 
199 
452 
69 
263 
2.11 
21.53 
1.10 
6.27 
.48 
3.84 
5.06 
Check VI 
94.83 
VII 
4.01 
Check VII 
88.74 
VIII 
.47 
Check VIII 
25.76 
The final counts in this vineyard showed satisfactory results in all 
plats on which two applications of arsenate of lead with soap had been 
made (Plats III, V, VI, VII, and VIII). Where, in addition to 
these two applications, a third application was made, directed solely 
against the second brood, the percentage of infested fruit was slightly 
reduced, but since the result was so satisfactory with two sprays (com- 
pare Plat IV with III and V) an extra or third application was unneces- 
sary. As an additional disadvantage, the fruit thus sprayed was badly 
stained at harvest time. A single application made at the time when 
the grape berries were just touching (Plat I) effected a marked re- 
duction of infestation, as did a later single application directly solely 
against the second brood (Plat II), but in both plats the results were 
far from satisfactory. Any late application is open thus to objection 
because of staining the fruit at the approaching harvest. Three ad- 
hesives, laundry soap (Plat V) , resin fish-oil soap (Plat III) , and fish- 
