156 Report or tHE BoTraANICAL DEPARTMENT OF THE 
EXPERIMENT NO. 17. 
Conducted ‘by T. E. Martin, West Rush. In a field of 18 
acres of potatoes, variety Sir Walter Raleigh, 17 acres were 
sprayed and one acre (18 rows), about the center of the field, left 
unsprayed. Between July 11 and September 20 the sprayed por- 
tion of the field received frequent light applications*® of bordeaux, 
the total quantity used being 178 barrels. The sprayer used 
was a one-horse, six-row, homemade outfit,*’ the same one used 
by Mr. Martin in his experiment in 1903. (See Bulletin 241, p. 
279 and Plate VIII.) 
The items of expense were as follows: 
900 pounds copper sulphate at 534 cents (less 1% dis- 

COUNL TON CAB) © sy pesieyeip’ RG * cahoartinny sey Segre ees ema $51 23 
140 pounds copper sulphate at 6 cents.............20. 8 40 
Freight on 140 pounds copper sulphate................ 40 
50 pounds paris green at' 15 cents (less 1% discount for 
ASLBD Lbs had Ps BAL a A tha teen eae ea 9 Set ko Se cele 7 43 
‘T-bushels imejat.25 cen tag aie als eins ty work bi ols eed ee 2 75 
15 days labor for man and horse at $3................ 45 00 
Wear on sprayer, repairs, etc............6.. ve idtepuiteeh oehatas 15 00 
MICE ose pe ins! oats eh Tales» i nangaers camelinieetakic a: ate Rha $180 21 - 
LTotal-cost of spraying per acteuc: wey. shes. day Slade $7 66 
The 17 acres sprayed yielded 4,875 bushels of marketable 
potatoes, or at the rate of 287 bushels per acre, while the un- 
Sprayed acre yielded only 225 bushels, making the gain due to 
spraying 62 bushels per acre. The greater part of the crop was 
sold at digging time or soon after at prices ranging from 40 to - 
50 cents per bushel. 
The writers visited this experiment twice. On September 9 
the contrast between sprayed and unsprayed areas was marked. 
There was no evidence that the unsprayed rows had been injured 
by bugs. Early blight was plentiful on the unsprayed, and this 
seems to have been the chief enemy, although it is likely that 
late blight, too, caused considerable injury during August. 
“The exact number of sprayings cannot be stated. 
“With one Bordeaux nozzle over each row. 

