CONTROL OF GRAPE-BERRY MOTH. i 
CONTROL EXPERIMENTS. 
STATUS OF SPRAY PRACTICE FOR GRAPE-BERRY MOTH CONTROL. 
When these investigations were undertaken the following prin- 
cipal facts were known about spraying for the control of the grape- 
berry moth: First, satisfactory control had not been effected by the 
use of any system of set-nozzle spraying, particularly in thrifty 
vineyards where foliage growth was heavy. Second, satisfactory 
control had been effected in Ohio 1 by using the trailer method of 
spraying at the time of the hatchings of second-brood larvae, usually 
in early August. This practice, however, left a heavy residue of 
spray material on the fruit at harvest time, which tended to exclude 
such fruit from a basket market. Third, two spray applications by 
the trailer method, the last when the grapes first touched in the 
clusters, had given satisfactory control on the Concord variety in 
the Chautauqua-Erie belt in 1915. This practice was to be 
thoroughly tried in northern Ohio on Concords and Catawbas. 
SCOPE OF EXPERIMENTS. 
From this summary of the knowledge available it appeared that 
the investigations should deal with three main points: (1) Time and 
number of spray applications, (2) chemicals used in spray materials, 
(3) spray residues left at harvest time. 
In studying these factors spraying experiments were conducted 
by the writers in 6 vineyards in 1916, in 9 in 1917, and in 15 in 1918, 
a total of 30 vineyards. These vineyards were selected for the op- 
portunity they offered for the advantageous study of any one or 
more of the important features enumerated above. Since little would 
be gained by considering each vineyard separately it has seemed 
desirable to assemble in Tables I, II, and III the data relating to the 
different vineyards and to bring together in similar form in Table 
IV the results of the experiments. 
TIME OF SPRAY APPLICATIONS. 
Former experiments 2 indicated that a spray application directly 
after grape blooming was important for the control of both grape 
rootworm beetles and grape-berry moth larvae. In the Sandusky and 
island sections of Ohio a spray application following grape bloom is 
usually made for the control of downy mildew, Plmmophora viticola, 
particularly on Catawba and Delaware varieties. This application 
directly following grape bloom was considered as the first spray in 
all of the experiments in which it was included. The second spray 
1 Goodwin, W. H., op. cit. 
2 Goodwin, W. H., op. cit. Johnson, Fred, and Hammer, A. G., op. cit. Isely, Dwight, 
op. cit. 
