The Potato Leafhopper and Its Control. 15 
HOW AND WHEN TO APPLY BORDEAUX. 
To control the potato leafhopper, Bordeaux mixture must be applied 
to the underside of the leaves. The spraying must be done thor- 
oughly, covering practically all of the foliage. Each side of every 
row of plants must be sprayed. 
A high pressure (150 pounds at least) should be maintained in 
order to cover the leaves with a fine mist, which gives a much better 
coating than does a coarse spray. (Figs. 13, 14.) 
In years when leafhoppers are abundant at least three applica- 
tions of Bordeaux mixture should be made, the first as soon as the 
leafhoppers have appeared on the plants. It is often possible at 
Fic. 13.—Good type of wheelbarrow sprayer effective for small patches. This sprayer holds 12 gallons, 
and 150 pounds pressure can be kept up when 2 nozzles are used. 
this time to add an arsenical and control the Colorado potato beetle. 
The second spray should be applied from 10 days to 2 weeks later, 
depending upon the amount of spray remaining on the plants and 
the amount of new growth. A third and even a fourth spray might 
be necessary in very hot, dry summers and in years when leafhoppers 
occur in vast numbers. 
As Bordeaux mixture is used for several purposes on potatoes—to 
repel fleabeetles and control certain diseases—it is most fortunate 
that it has been found to be a control for leafhoppers and “ hopper- 
burn” and may fit nicely into the regular spraying schedule. 
