Porators 1389 
has been carrying on cooperative experiments with farmers scat- 
tered from one end of the state to the other. The farmer does the 
work according to his own method, the station provides for proper 
check rows, and assists in measuring the areas and weighing the 
product. The grower keeps accurate account of all expenses and 
profit or loss from the spraying. During the seven years the 
average cost of spraying an acre has run from $4.15 to $5.90. 
The increased yield per acre has been from 18.5 bushels to 62.2 
bushels and the net profit per acre from $8.53 to $24.86. This is 
the average highest and lowest return from all the experiments in 
different years. The greatest gain, of course, has been in years 
when blight was severe, the smallest being in 1908, when there 
was scarcely any blight. Doubtless, much of the gain that year 
was due to decreased damage from flea beetles because of bordeaux 
applications. The average increase in yield per acre for the entire 
period was 44.1 bushels, with an average net profit of $16.77 for 
the seven years. At Geneva the gain per acre due to spraying 
every two weeks was 97.5 bushels; at Riverhead 45.7 bushels. 
The gain due to spraying three times at Geneva was 69 bushels; at 
Riverhead 25 bushels. 
Few appreciate the fact that the potato makes its most rapid 
growth in the last two weeks of its life. If the green leaf, then, is 
impaired or destroyed before the plant has lived out its natural 
life, the yield may be so decreased as to do away with the profit 
altogether, or the increase by preserving it by spraying, after pay- 
ing the expense, is clear gain. 
RECAPITULATION 
To briefly summarize and emphasize the foregoing it is apparent: 
1. That humus well mixed with the soil, and frequent surface 
stirrings of the same, will materially help to store up and retain 
moisture or a water supply against the period of greatest need, 
when the tubers are forming and the tops are evaporating water 
most rapidly. 
2, That deep plowing and planting and non-hilling in ordi- 
nary dry seasons will all tend to the conservation of moisture. 
