92 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
experiment field contained eight acres of potatoes of the variety 
World’s Superior. The soil was a gravelly clay loam sufficiently 
rolling to give fair surface drainage. The potatoes were planted 
about May 15. ; : 
Three rows were left unsprayed for a check and the remainder 
of the field sprayed five times with bordeaux mixture of the 
6-6-60 formula. The sprayer used was the same one used in the 
1905 experiment, viz., a one-horse, four-row Watson potato 
sprayer. In the first two sprayings one Vermorel nozzle per row 
was used while in the last three sprayings when the vines were 
large two nozzles per row were used. The water required in the 
_ preparation of the bordeaux was conveniently obtained from a 
well a short distance from the field. The dates of spraying were 
July 3, 14, 31, August 9 and 21. Paris green was used with 
the bordeaux in the first two sprayings at the rate of one pound 
to sixty gallons. On the same dates, the unsprayed rows were 
treated twice with one pound of paris green in sixty gallons of 
lime water. So far as treatment for “bugs” is concerned the 
sprayed and unsprayed rows received identically the same care. 
Late blight was the principal enemy fought in this experiment. ° 
It was well established on the unsprayed rows as early as Au- 
gust 7 and before the close of the season injured them con- 
siderably. The contrast between the sprayed and unsprayed rows 
was so marked that even after the foliage was all dead the un- 
sprayed rows were distinguishable at a considerable distance. 
The items of expense for spraying eight acres of potatoes five 
times were as follows: 
2234 ..lbs.; copper: sulphatée@ \7@.se os 03s ok a ele oe Uh ae oe $22.61 
14“bbl: lime. @. $1.30; 2.47 ddi wk Whee. ee Ad ses ae 1.95 
sv Slbs. paris green’ @ 256 4662s vies weet ae a oe 3-75 
46°. hrs. labor, tor “man (@ vse7. Se eas eos ce ts ate ee 4.50 
30° hrs. ‘labor for horse @'10¢ hha a AA 3.00 - 
Wear‘ on itsprayer ca saoh Get Ae eo A eee Bs ck 5.00 
Total, tata Up ARO Fe HEE PI Se $40.81 
The total expense of spraying was $5.10 per acre or $1.02 
per acre fot each application. 
The test rows were dug with a potato digger on September 18. 
They were 1,243 feet long by 3 feet wide, 11.68. rows being 
required to make an acre. The yields were as follows: 
a ae an 
