New York AGRICULTURAL EXPERIMENT STATION. 179 
The experiment.—The experiment included sixty rows of po- 
tatoes, 100 feet long and three feet apart. The hills were 18 
inches apart in the row, the planting being done by hand. The 
land grew corn in 1903. No manure or fertilizer was applied for 
the potato crop. These potatoes were not planted for experi- 
mental purposes but merely to fill out the ends of the rows used 
in some other spraying experiments. Accordingly they were not 
planted with the care usually taken in experimental-work. They 
were planted quite late, about June 10. The variety was Rural 
New Yorker No. 2. 
When the plants were 6 to 9 inches high they were attacked 
by hordes of Colorado potato beetles and treatment being de- 
layed considerable injury was done. Some of the plants were 
almost completely defoliated. On July 26, paris green in lime- 
water (1 pound to 50 gallons) was applied over the entire 60 
rows. Rain coming the same day the treatment was not as 
effective as desired, hence another application of paris green 
was made on July 29. After this there was no more trouble 
from beetles until August 12, when they were again sufficiently 
numerous on the check rows to require another application of 
paris green. This time only the check rows were treated. 
PLAN OF THE EXPERIMENT. 
The sixty rows were divided into four series of 15 rows each 
as follows: 
Series I. Rows 1, 5,9, 13, 17, 21, 25, 29, 38, 37, 41) 45, 49, 53, 57 
were left untreated for a check. 
Series IT. Rows 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50, 54, 
58 were treated with soluble bordeaux. 
Series [11.° Rows 3, 7, 11,.15,°19, 23, 27, 31,35, 39, 43) 47) 51, 55, 
59 were treated with soda bordeaux. 
Series IV. Rows 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 
60 were treated with the regular lime bordeaux. 
Series IT, III and IV were very thoroughly sprayed, by means 
of a knapsack sprayer, four times, August 2, 8, 19 and Septem- 
ber 1. In the last two sprayings 16 gallons were required to 
spray the fifteen rows of each series. 
PREPARATION OF SPRAY MIXTURES. 
Soluble bordeauxr—-(1) Solution of copper suplhate prepared by 
dissolving one-half pound copper sulphate in one gallon of water. 
