80 Report OF THE BOTANIST OF THE 
A second object of the experiments was to determine which is 
the more profitable: To spray every two weeks throughout the 
season, as is usually recommended; or to make only three spray- 
ings during the season. 
DURATION. 
Of course it is necessary to continue the experiments several 
years before a reliable average can be obtained. The chief 
cause of variation in the results is the variation in weather 
conditions, and since the average weather conditions for any 
period of ten years approximate very closely the average for 
any other period of ten years, it would seem that the proper 
length of time to continue the experiments is ten years. Ac- 
cordingly, the Station expects to spray potatoes every year for 
ten consecutive years, and the plan of the experiments each 
year will be the same as in this first year’s work. Each year 
the increase in yield per acre due to spraying will be accurately 
determined, and at the end of the ten years the results will be 
averaged. 
However, it is not the intention to withhold the publication 
of the results until the experiment is finished. Each year, or as 
often as seems advisable, there will be published a _ builetin 
giving a detailed account of the results of unpublished experi- 
ments and a summary of the results of the preceding years, in 
order that the public may be kept informed as to the progress 
of the experiments. These bulletins will also contain other 
matter pertaining to potato spraying and potato blight. There- 
fore, this bulletin is the first of a series on the subject of 
potato spraying. 
LOCATION OF ENPERIMENT FIELDS. 
In some localities potatoes blight more frequently and more 
severely than in others, and, consequently, spraying produces a 
larger increase in yield in some localities than in others. On 
this account it was thought best to conduct the experiments in 
at least two localities. One of the places selected was on the 
Experiment Station farm at Geneva, and the other on the farm 
of Mr. F, A. Sirrine, three miles north of Riverhead, on Long 
