58 Bulletin 140. 



In treating the potatoes for this pest, timeliness is an important 

 consideration. When the grubs are small, four ounces of Paris green 

 to the barrel (50 gallons) of water will be effective. If, however, they 

 are allowed to become half to two-thirds grown, the quantity of Paris 

 green must be increased to six or even eight ounces to 50 gallons of 

 water. The Paris green can be applied with the Bordeaux mixture nearly 

 as easily as it can be applied with clear water or with plaster. During 

 the early part of the season and until the potato- beetles have ceased 

 their work, when it is found necessary to apply Paris green it should 

 be combined with Bordeaux mixture, which serves to prevent ravages 

 of bhght and the flea-beetle, and when Bordeaux mixture is applied as 

 a prev^ention of blight and to drive away the flea-beetles, Paris green 

 should be mixed with it to destroy at the same time the Colorado 

 potato-beetles. Thus by judicious work several enemies may be 

 destroyed by one application. 



It is always important in using Paris green to know that the quality 

 is good. It may be tested easily in the following manner. Put a 

 small quantity of Paris green to be tested into some common house- 

 hold ammonia or hartshorn. If the Paris green is good, it will all 

 dissolve, leaving no sediment. If it is impure there will be more or 

 less sediment remaining. It is always well to apply this simple test 

 before treating a large area, as but a few minutes are required to make 

 the test, and much valuable time may be saved, as Paris green is not 

 always true to name. 



Blight. 



The prevailing difficulty during the present year has been the late 

 blight and the resulting potato rot. Nearly every farmer has acquired 

 the habit of treating potatoes for the Colorado potato-beetle, but 

 previous to the present season comparatively few have been impressed 

 with the necessity of treating potatoes for the blight. In the case of 

 the beetles it is clearly evident when the ravages begin, and then the 

 remedy may be applied. In case of the blight and the flea-beetle the 

 remedy is largely preventive and should be applied before the neces- 

 sity for treatment is apparent, for once blight gets started it is difficult 

 to hold in check. There is no subject relating to potato culture which 

 is now of more importance than the blight. It is probable that it has 

 come to stay, and while its ravages may be much greater some years than 



