EXPERIMENT STATION BULLETINS. 



493 



POTATOES AXD EOOT CROPS. 



The season was quite favorable for potatoes until September, when late blight 

 favored by wet weather checked the growth of the tubers. The damage from 

 the disease was confined to the tops and to a percentage of small potatoes larger 

 than usual. Owing to the frequency of the rains, spraying would have been im- 

 practicable and was not attempted. The vines were sprayed earlier in the season 

 against early blight, and up to the end of August remained in a healthy condi- 

 tion. After using Paris green against potato bugs for several seasons, getting 

 the poison from different sources, and using it at different strengths in water 

 and Bordeaux mixture, it seems quite certain that this material cannot be relied 

 upon when using the standard formula of one pound in 100 gallons of water. 

 Careful observations during the past season, showed that Paris green used at this 

 strength and obtained from three different places killed less than ten per cent 

 of the young larvae, about one-quarter full grown and none of the full grown 

 larvae, nor any of the beetles. By gradually increasing the dose, much better, 

 though by no means satisfactory, results were obtained by using li^. lbs. for 100 

 gallons and adding an extra pound of lime. Further observations will be taken 

 next season when the dose will be increased to 2 lbs., or more if necessary. There 

 is no reason why Paris green should not be subject to the same regulations as 

 commercial fertilizers, for its effectiveness depends upon its composition equally 

 as much. Scab accounts largely for the low yield of the six varieties planted 

 June 13 and heading the list in the following table. Though the seed had been 

 treated with corrosive sublimate, the treatment was rendered ineffective owing 



