Nuw York AGRIcULTURAL EXPERIMENT STATION. 143 
Average-total cost of spraying per acre, $4.98. 
Average cost per acre for each spraying, 93 cents. — 
Average net profit per acre, $24.86. 
SUMMARY OF BUSINESS EXPERIMENTS IN 1903 °° 
Total area sprayed in six experiments, 61 1-6 acres. 
Average increase in yield per acre, 57—bushels. ° 
Average total cost of spraying per acre, $4.98. 
Average cost per acre for each spraying, $1.07. 
Average net profit per acre, $23.47. 
VOLUNTEER EXPERIMENTS. 
In one way or another the writers have learned of a consider- 
able number of farmers who sprayed potatoes in 1904 and left a 
portion of the field unsprayed. These farmers were requested to 
measure the yield on sprayed and unsprayed rows and report the 
results to the Station together with an account of the method of 
spraying and other data pertaining to the experiment. About 
fifty reports were received, but a few of them were incomplete 
on some essential point. Forty-one are considered worthy of 
publication. Some of these experiments appear to have been 
very carefully conducted, while some others have been managed 
and reported somewhat carelessly. However, in every case, the 
figures given as the increase in yield due to spraying are based 
upon actual weight or measurement. No estimates are included. 
These experiments are called “ volunteer experiments ” because 
the Station had nothing to do with them. They were planned 
and carried out entirely by the farmers themselves. The credit 
for them belongs to the farmers, not to the Station, and the 
writers wish here to thank all the gentlemen who have so kindly 
contributed information in regard to their experiments. Like- 
wise, the blame for any inaccuracy in the published reports is 
the number of acres in each experiment. Computed by the second method 
the average increase in yield is 70+ bushels per acre. Likewise the average 
cost of spraying and the average net profit have been computed by the first 
method. 
It will be observed that these figures differ from those published in 
Bulletin 241, p. 283. This is in consequence of using a different method of 
computation as explained in the previous footnote. The figures given here 
have been obtained by the first method while those given in Bulletin 241 
were obtained by the second method. In future bulletins the first method 
only will be used. 
