REPORT OF THE BOTANICAL 
DEPARTMENT. . 
POTATO SPRAYING EXPERIMENTS IN _1908.* 
F. C. STEWART, G. T. FRENCH anp F. A. SIRRINE. 
SUMMARY. 
This bulletin gives the results of the seventh year’s work in 
the ten-year series of potato spraying experiments begun in 
1902. During 1908 the experiments were conducted along the 
same lines as in previous years. Twenty-seven separate ex- 
periments are reported. 

TEN-YEAR EXPERIMENTS. 
At Geneva, six sprayings increased the yield 39 bu. per acre 
and three sprayings increased it 294 bu. although both early and 
late blight were wholly absent and there were but few flea beetles. 
The chief trouble was tip burn. There was no rot. At River- 
head the gain due to five sprayings was 15.3 bu. per acre and to 
three sprayings 10.75 bu. Here, the chief enemies were the flea 
beetle and early blight. There was no late blight and no rot. 
FARMERS’ BUSINESS EXPERIMENTS. 
In fourteen farmers’ business experiments, including 200 acres, 
the average gain due to spraying was 18.5 bu. per acre; the aver- 
age total expense of spraying, $4.30 per acre; and the average 
net profit, $8.53 per acre. In five of the experiments spraying 
was unprofitable. 
VOLUNTEER EXPERIMENTS. 
Eleven volunteer experimenters reported gains averaging 66.3 
bu. per acre. These experiments do not fairly represent the 
results obtained from spraying in 1908. 
The chief trouble with potatoes in New York in 1908 was tip 
burn, caused primarily by. dry weather, but aggravated by flea 
beetles, leaf hoppers and other insects. Early blight was rare 
and late blight and rot almost wholly absent. The experiences 
of 1908 indicate that it is unwise to neglect spraying in dry 
seasons. sh 

* A reprint of Bulletin No. 311. 
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