40 BULLETIN 19, TJ. S. DEPARTMENT OF AGBICT7LTUBE. 
to the underside of the grape leaves by holding a short rod. one end 
connected to the spray hose and the free end carrying a large nozzle 
of the cyclone type directed upward at right angles to the rod. See 
PL III. rig. 1.) Eiiective results in killing the nymphs by this method 
appeared to depend more upon the person manipulating this rod than 
upon the type of sprayer used or the number of pounds of pressure 
applied, providing the pressure was not allowed to drop below 75 
pounds. Of course with the higher pressure larger areas can be cov- 
ered in a given time than with the low pressure. Yet the most ettec- 
tive work done in the control of this pest corning under observation 
: iter was accomplished with a tractor machine, with a pressure 
fluctuating between 70 and 125 pounds, in the hands of a very thorough 
vineyardist. This feature is emphasized here because the small vine- 
yardist. being under the impression that an expensive high-pressure 
spray outfit is necessary, is frequently deterred in attempting to con- 
trol this pest, whereas the most important thing is care in the direction 
of the spray so that the greatest number of nymphs will be drenched, 
and this can be done with the same tractor machine that is used for 
applications against the grape rootwomi. On the other hand, it is 
doubtless much more economical for the vineyardist with large areas 
to cover to have larger high-pressure outfits, since with them two or 
even more leads of hose may be used PI. III. fig. 2 . making it possible 
vei large areas hi a very short time. This is highly desirable, 
since there are only about S to 12 days during which the maximirm 
number of nymphs is present upon the foliage. 
In order to lessen the time required to make the application and 
to reduce the cost, many attempts have been made to apply the spray 
to the underride of the grape foliage by means of a fixed nozzle ar- 
rangement instead of making the application by the trailer method 
described above. The chief difficulty arising in the use of a fixed- 
nozzle arrangement is that such a device applies no more liquid to 
a vine carrying a large amount of dense foliage than to one carrying 
a moderate amount of more widely spaced foliage; hence it frequent ly 
happens that much more spray than is necessary is applied to the 
vine carrying light foliage and not enough is applied to the one carry- 
ing dense foliage. 
The types of fixed-nozzle arrangement are being, tried out hi the 
vineyards of the Lake Erie Valley. One of these was for a tractor or 
a gasoline-engine power sprayer, and was devised and used by Mr. 
F. Z. Hartzell. 1 The other arrangement was used for a steam-engine 
power -prayer. PI. II. fig. 2/ Both of these arrangements are 
reported to have given fairly satisfactory results hi killing nymphs 
where the foliage was not very dense. In most cases, however, suc- 
iBul. b44 ; X. Y. [Gena a.) Exp. £ ■ ,- Is. I-IV. 
