180 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
At no time during the season did the difference in treatment 
seem to have any effect on the foliage. The yields were as fol- 
lows: 
TABLE XV.—SHOWING YIELDS IN THE ARSENITE OF SODA EXPERIMENT. 






YIELD OF 29 ROWS. YIELD PER ACRE. 
TREATMENT, — 
| Marketable. | Small. Marketable. Small, 
, Lbs. Lbs. Bu. lbs. | Bu. lbs. 
Bordeaux with arsenite of soda...... 2,928 297 | 226 14 | 22 57 
BGPdeaus Onl ¥ accuse botacsla wake teiteme: 2,808 254 | 216 58 | 19 37 
| 

Difference in favor of bordeaux with arsenite of soda, 9 bu. 
16 lbs. marketable tubers per acre. 
We believe the results of this experiment to be trustworthy. 
They indicate that the arsenite of soda may be used safely with 
bordeaux at the rate of one quart of the stock solution (Kedzie 
formula) to fifty gallons. Probably considerably larger propor- 
tions of the arsenite would not be harmful. Arsenite of soda is a 
cheaper poison than paris green and remains in suspension better. 
Based on the arsenic it contains one quart of arsenite-of-soda stock 
solution is equivalent, in poisoning properties, to eight ounces of 
paris green. 
DOES BORDEAUX MADE WITH COLD WATER INJURE 
POTATO FOLIAGE? 
In making bordeaux for potatoes is it safe to use very cold water 
such as comes from deep wells? Will the foliage be injured? Such 
questions as these are asked occasionally. Some potato growers 
hold that spraying potatoes with very cold bordeaux on a hot, 
sunny day causes injury to the foliage. They advise that water 
from deep wells be allowed to stand in the air and warm before it 
is used for spraying potatoes. 
entire experiment with bordeaux alone. Only the younger bugs disappeared. 
The half-grown slugs continued their depredations. Accordingly, on July 20 
the spraying was repeated and this time done properly. At the same time 
the bugs on the bordeaux-only rows were hand picked and there was no 
further trouble. This experience leads to the conclusion that while newly- 
hatched bugs may be successfully fought by thorough spraying with bordeaux 
alone, half-grown slugs can not be controlled in that way. Even when 
poisons are used bugs are much more easily killed while they are small. 
