. 
120 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
cost for each spraying, 92 cents; and the average net profit, $29.85 
per acre. 
SopA BorDEAUX vs. LIME BORDEAUX. 
In comparative tests of efficiency of these fungicides, rows 
sprayed four times with lime bordeaux outyielded rows similarly 
sprayed with soda bordeaux by 9 bushels per acre in one test and 
by 35 bushels per acre in another test. For use on potatoes, soda 
bordeaux is not superior to lime bordeaux. 
BorpEAUxX WITH AND WITHOUT PaRIS GREEN. 
Potatoes are in no way injured by paris green properly applied ; 
viz., in moderate amount (one to two pounds per acre) with bor- 
deaux mixture. 
BorRDEAUX WITH AND WITHOUT ARSENITE OF SODA. 
Arsenite of soda may be safely used with bordeaux at the rate 
of one quart of the stock solution (Kedzie formula) to fifty gallons. 
CoLp vs WARM BORDEAUX. 
Potato foliage was in no way injured by spraying on hot, sunny 
days with bordeaux having a temperature of 4o degrees to 54 
degrees Fahr. It appears that no attention need be paid to the 
temperature of the water used in making bordeaux for spraying 
potatoes. 
Potato TROUBLES IN 1905. 
In unsprayed fields the loss from blights, rot and flea beetles was 
at least fifty bushels per acre on the average. Most of this loss 
was due to late blight and the rot which follows it. 
DorEs SPRAYING PREVENT Ror? 
The general tendency of spraying is to reduce the amount of 
rot. In most cases the reduction is very marked; in some cases 
there is no difference; and occasionally spraying increases the 
amount of rot. It depends on weather conditions and the thorough- 
ness of spraying. But whatever the effect on rot, sprayed plants 
always give a larger yteld of marketable tubers. 
