20 
BULLETIX 837, U. S. DEPARTMENT OF AGRICULTURE. 
ent authorities. To determine the most efficient of these, experiments 
as shown in Table VIII were conducted in 1916. 
Table VIII. — Relative efficiency of different soaps as spreaders and adhesives, 
SchonJmrdt vineyard. Venice, Ohio, 1916. 
Pounds 
in 50 
gallons. 
Spray 
mate- 
rials 
com- 
bined 
with 
soaps. 
Gallons 
spray 
mate- 
rial 
per 
plat 
second 
appli- 
cation. 
In- 
crease 
over 
resin 
soap. 
Results in grape-berry moth control. 
Kind of soap used. 
Num- 
ber 
vines 
exam- 
ined. 
Num- 
ber 
clus- 
ters 
exam- 
ined. 
Num- 
ber 
grapes 
exam- 
ined. 
In- 
fested 
grapes. 
Variety. 
Soft 
2 
9 
0) 
C 1 ) 
0) 
140 
100 
75 
Per ct. 
86 
33 

i 10 
\ 10 
f 12 
1 io 
/ 22 
i 34 
790 
342 
608 
198 
735 
311 
1.050 
IS. 960 
12,996 
14,592 
7. 524 
17,640 
11.918 
25.200 
Perct. 
17.04 
Concords. 
24. cS3 catawDas. 
6. 78 Concords. 
Resin fish-oil 
1 
6.11 ; Catawbas. 
8.50 Concords. 
8. 37 Catawbas. 
41.16 Concords. 
Checks 
1, 019 
30, 5 < 
<3. 12 
v^a«iN\ oas. 
1 Bordeaux 3-3-50, arsenate of lead commercial powder 2h pounds to 50 gallons. 
Adjoining grape rows, each row including Concord and Catawba 
varieties, were sprayed three times during the season, the first ap- 
plication three to five days after grape bloom. June 27, the second 
when the grapes touched in the clusters. July 13, and the third at 
the beginning of the hatching period of second-brood larva?, August 
3. All spraying was done by the trailer method with medium disk 
angle nozzles and at a pressure of 150 pounds. The soaps were used 
as spreaders in mixtures of Bordeaux 3-3-50 and arsenate of lead 
powder 2^ pounds to 50 gallons. The season was unusually dry dur- 
ing July and August, favoring both adherence of spray materials 
and the development of the grape-berry moth. The Concords were 
harvested September 29 and the Catawbas October 10. 
The soft soap used was a bulk product made especially for use in 
commercial laundries. This soap dissolved readily in hot water, but 
when applied to grapes formed in globules on the leaves and grape 
berries and dried in large drops. This condition was reflected in 
the percentages of infested grapes at harvest time. 17 per cent on 
Concords and 25 per cent on Catawbas. This increase in infestation 
on the Catawba variety did not occur with the laundry or resin soap, 
and so seems to indicate less adhesive power late in the season in the 
soft soap, since the Catawbas were harvested 12 days later than the 
Concords. The laundry soap used (PI. IV. fig. 1) was the com- 
mon yellow -bar soap, chipped and dissolved in hot water. This 
spread smoothly over the grape foliage and berries and gave a satis- 
factory covering when the spray was directed on the clusters for a 
sufficiently long time, but the amount required to ,: wet " them was 
33 per cent greater than when the resin soap was used. When the 
third-spray application is used, as in this experiment, the adhesive 
