116 REPORT OF THE BOTANICAL DEPARTMENT OF THE 
REMARKS ON THE VOLUNTEER EXPERIMENTS IN 1906. 
The yields given in Table XVI are all based upon actual weight 
or measurement and refer to marketable tubers except in Experi- 
ments 30 and §2 in which the potatoes were not sorted. 
The expense of spraying as reported by the various experi- 
menters includes, in all cases, labor and the expense of materials 
for making the bordeaux mixture. In some cases an allowance 
for wear of the sprayer is included, and sometimes, also, poison for 
“bugs.” Because of this lack of uniformity in making up the ex- 
pense accounts the amounts given in Table XVI in the column 
headed, “Cost per acre for each spraying,’ do not admit of close 
comparison. 
Several of the experiments have interesting features which could 
not be shown in the table; hence they are presented here. 
Experiment No. 1.— Mr. C. M. Dennis, who conducted this ex- 
periment, reports that the unsprayed rows died about three weeks 
earlier than the sprayed portions of the field. They were not in- 
jured by “bugs.” There was a little loss from rot, amounting to 
2.5 bu. per acre on the sprayed row and 6.3 bu. per acre on the 
unsprayed row. The gain due to spraying was determined by 
comparing the yield of an unsprayed row 396 feet long with that 
of a nearby sprayed row of the same length, the potatoes being 
carefully weighed in both cases. The sprayed row yielded 458 
pounds, the unsprayed 247 pounds. 
Experiment No. 2.— This experiment was conducted by T. E. 
Martin, West Rush. Mr. Martin is an ardent advocate of spraying. 
In 1906, he sprayed 18 acres I5 times going over the rows in both 
directions each time. Although the spraying cost about $12 per 
acre it was highly profitable. The following account of Mr. 
Martin’s methods is an extract from a paper which he read before 
the Experimenters’ League at Ithaca, N. Y., Feb. 22, 1906. 
“Tn spraying, 331 55-gallon barrels of bordeaux mixture were 
applied to the crop, beginning July 2 and finishing September Io. 
About one ton of crystal sulphate of copper and 15 barrels of Ohio 
marblehead. stone lime were used, keeping stock solutions of both 
in readiness. Ferrocyanide of potassium, in an oil can, is ever at 
hand to test the mixture if there is any doubt about the copper not 
being neutralized. Lime in excess is always safe, yet, apparently, 
does not lessen the ‘ burning,’ or increase the efficiency of the bor- 
deaux. The standard formula of bordeaux is followed: 6 lbs. 
_ copper sulphate, 6 lbs. lime to 50 gallons of water. Two pounds 
