146 REvORT OF THE BOTANICAL DEPARTMENT OF THE 
EXPERIMENT NO. 38. 
Conducted by W. H. Grinnell, Albion. About two acres of 
potatoes, variety Sir Walter Raleigh, were sprayed four times 
with a two-horse outfit consisting of a barrel spray pump 
mounted on a two-wheeled cart with nozzles so arranged as to 
cover three rows at a time with three nozzles per row. One 
man drives while another works the pump. The total expense of 
spraying, including both labor and materials, was about $12. 
One row 1414 rods long was left unsprayed. The bugs were 
kept off this row by hand picking so that they did but little 
damage. The yield was 62 pounds of marketable tubers and 
38 pounds of culls. A sprayed row 20 feet distant yielded 144 
pounds of marketable tubers and 32 pounds of culls. Thus 
the yield was at the rate of 6234 bushels per acre for the 
unsprayed and 14534 bushels per acre for the sprayed making 
a gain of 83 bushels per acre or 133 per ct. in favor of spraying. 
Mr. Grinnell thinks that the increased yield ‘on the sprayed 
rows was chiefly due to their having been protected against 
flea-beetles which caused much havoe on the unsprayed row. 
The unsprayed row also blighted considerably more than the 
sprayed, but there was no rot on either sprayed or unsprayed. 
Price of potatoes at digging time, 60 cents. 
EXPERIMENT NO. 4. 
Conducted by ©. W. Driggs, Elba, Genesee County. Ten 
acres of potatoes (Carman No. 3 and Rural New Yorker No. 2 
mixed) were sprayed four times with a two-horse, four-row 
sprayer pump by hand.. There was but one nozzle over each 
row. Generally, the outfit was operated by one man. In the 
last two sprayings the plants were sprayed twice In opposite 
directions, that is, double-sprayed. | 
Three rows 40 rods long were left unsprayed in a 4-acre field. 
One of these rows yielded 5 bushels (marketable and culls 
together) while an adjacent sprayed row yielded 6 bushels, the 
difference being at the rate of 22 bushels per acre—110 bushels 
per acre for the unsprayed and 182 bushels for the sprayed. 
The unsprayed rows died about ten days before the sprayed 
rows were killed by frost. There was very little rot anywhere 
