New York AGRICULTURAL EXPERIMENT STATION. 183 
fields. Flea beetles appeared in injurious numbers at several 
different points in the State, but were especially numerous and 
destructive on Long Island during the last ten days in July. 
3 
Colorado potato beetles or “bugs” were unusually troublesome. 
In many fields the plants were stripped of their foliage in spite of 
efforts made to control them. In some localities the demand for 
paris green exceeded the available supply with the result that local 
prices were materially advanced. 
Judging from the results of numerous experiments the loss from 
blights, rot and flea beetles in unsprayed fields could not have been 
less than fifty bushels per acre on the average. In the 13 farmers’ 
business experiments the average gain due to spraying was 4614 
bushels per acre, while 50 volunteer experimenters reported gains 
averaging 59% bushels per acre; and it should be borne in mind that 
these figures represent only a part of the damage done by blight and 
rot, because in only a few of the experiments was either the blight 
or the rot completely controlled. 
DOES SPRAYING PREVENT ROT? 
It is generally stated that spraying will prevent that rot of the 
tubers which often follows an attack of late blight, Phytophthora 
infestans. The theory advanced is, that spraying prevents the 
growth of the blight fungus on the leaves so that there are no 
spores, or at least fewer spores, to fall upon the ground and cause 
rot; hence there should be less rot where the plants have been 
sprayed. 
As a matter of fact there are on record numerous experiments 
in which it was shown conclusively that the loss from rot was 
greatly reduced by spraying. Probably the most notable example 
is an experiment made by Jones and Morse®’ at the Vermont 
Station in 1904 in which unsprayed potatoes rotted at the rate of 
245 bushels per acre while among sprayed potatoes under condi- 
tions otherwise parallel the loss from rot was only 27 bushels per 
acre. 
However, there are also on record instances in which spraying 
had no appreciable effect in reducing the amount of rot; and it 

* Jones, L. R. & Morse, W. J. Vt. Agr. Exp. Sta. Rep. 17: 380, 300. 
