188 Report OF THE BOTANICAL DEPARTMENT OF THE 
lowed when in doubt, is the following: Commence spraying 
when the plants are 6 to 8 inches high and repeat the treatment 
regularly at intervals of ten to fourteen days as long as the 
plants live. 
“ Usually ‘bugs’ must be treated when the plants are a few 
inches high. Often flea-beetles are prevalent at the same time. 
By using bordeaux and poison together both these insects may 
be more effectively fought than by using poison alone. In an- 
other two weeks the second brood of bugs has appeared. A 
second spraying must be made for these. In two weeks more ~ 
the plants are in bloom and quite large. They must now be 
sprayed for blight, and it is not easy to reach the lower leaves. 
Unless the two early sprayings have been made, it is difficult to 
protect the lower leaves and they fall a prey to both early and 
late blight. Where the vines grow large this is an important 
matter. ; 
“ Another advantage in commencing early is that the plants 
are always protected against an outbreak of late blight. As a 
rule it is unsafe to postpone spraying until the appearance of 
blight. Usually the blight becomes thoroughly established in a 
field before it is observed. In any case it is necessary to act very 
promptly, and there are likely to be unforseen hindrances, such 
as lack of materials or the sprayer being out of order. Then, too, 
it often happens that the outbreak of blight occurs during a period 
of wet weather when it is almost impossible to get into the field 
to spray. The only sure way to avoid such difficulty is to com- 
mence early and spray regularly at intervals of 10 to 14 days, 
as above directed. One of the chief causes of failure is beginning 
too late. 
“The frequency of the spraying should depend somewhat upon 
the thoroughness with which the work is done. In giving the 
above directions for spraying it is assumed that the quantity of 
bordeaux applied at each spraying is at least 40 gallons per acre. 
If using a sprayer which applies but 25 gallons per acre, once in 
two weeks is not often enough. In such cases an application 
should be made every week. When the vines are large and the 
weather favorable to late blight at least 100 gallons per acre are 
required to do good work. The general tendency of farmers is 
