CONTROL OF GRAPE-BERRY MOTH. 
25 
first application, but where the second had not been applied slightly 
more material was required for this third application than for the 
second application in adjoining plats. This difference is accounted 
for by the fact that the material from the second application re- 
mains on the grapes and overcomes the waxy bloom, thereby allowing 
quick wetting. 
The following comparisons of single-nozzle, double-nozzle, and 
spray-guns for use in trailer spraying were made : 
Table X. — Experiments icith single and double nozzles and spray guns for use 
in trailer spraying of grapes. E. Dunning's vineyard, Avon Lake, Ohio, 1918. 
[First spray application for grape-berry moth control, June 19.] 
Plat No. 
Number 
nozzles 
per rod. 
Nozzle 
aper- 
tures. 
Pressure 
per 
square 
inch. 
Time to 
spray 
150 
gallons. 
Number 
rows 
sprayed. 
Percent- 
age of 
time 
saved. 
Percent- 
age of 
material 
saved. 
1 
1 
2 
0) 
Inches. 
Pounds. 
175 
175 
200 
Minutes. 
64 
50 
38 
14 
16 
16 

21.8 
40.6 
o 
2 
14.2 
3 
14.2 
i Spray guns, 1 to each hose line. 
In Table X it is seen that two medium nozzles per rod saved 21 
per cent in time and 14 per cent in materials as compared with one 
large nozzle. Spray guns saved 40 per cent in time and used no more 
material than two nozzles per rod, but an angle at the nozzle end of 
a rod is a necessity for thorough covering of the grape clusters. The 
writers believe that for the average vineyard two disk nozzles, at an 
angle of 45°, to each rod, with -jVinch apertures and a pressure of 
175 pounds, will be found most satisfactory. 
Materials and labor vary so greatly from season to season and in 
local sections that figures as to the cost of spraying are of little value. 
The statement can be made that an average of about 5 acres of 
thrifty vineyards can be sprayed by two men with a team in a day 
and will require from 100 to 250 gallons, averaging 147 gallons 
(Tables I and II) per acre for the first application, and from 160 to 
300, with an average of 224 gallons per acre, for the second applica- 
tion. 
CONCLUSIONS. 
The grape-berry moth has been a more general pest in northern 
Ohio than in other commercial grape sections because of the follow- 
ing conditions: (1) Production of the late maturing Catawba va- 
riety, (2) cultural methods favorable to successful wintering of the 
insect, (3) harvesting methods which leave the insect in the vine- 
yards, (4) a grape training system which prevents spray materials 
from reaching the clusters when applied with set nozzles. 
