5IO 



Journal of Agricultural Research voi. xiii, no. io 



y.jj, as compared to 0.84, 1.96, and i.oo per cent in 1916 for the three 

 fields, an average difference of 6.65 per cent. The data for the Irish 

 Cobbler show 4.04, 1.57, and 5.79 per cent in 1913, as compared to 2.1, 

 1.57, and 1. 17 per cent in 1916 for the three fields, an average difference 

 of 2.19 per cent. 



Table II. — Prevalence of blackleg of Irish potatoes at Presque Isle, Me., during 191$ 



and igi6 



SPAUIvDING ROSE 



Date of count. 



June 30 . 

 July 14.. 

 August 2-^ 



Total . 



June 30 . . 

 July 14. . . 

 August 23. 



Total. 



June 30 ... . 



July 14 



August 23 . . . 



Total. 



Field No. 



Number 



of 



healthy 



hills. 



224 

 162 



551 



200 

 196 

 256 



652 



200 

 297 

 310 



807 



1915 



Number 



of 



diseased 



hills. 



Percent- 

 age of 

 disease. 



2. 61 

 II. 76 

 23 I 12. 43 



51 



9 

 18 

 26 



8.47 



1916 



Number 



of 



healthy 



hUls. 



1,500 

 1,490 



300 



3.290 



4-31 312 



8. 41 I 290 



9. 22 I 400 



53 



IS 

 27 

 26 



68 



7-52 



6.98 

 7-74 



7-77 



600 

 480 

 300 



1,380 



Number 



of 



diseased 



hills. 



IS 



28 



14 



Percent- 

 age of 

 disease. 



0.79 



I. 00 



■23 



3-70 

 I. 02 

 I. 23 



I. 96 



I. 96 



.41 



o 



I. 00 



IRISH COBBLER 



In general, the results presented in Table II for the years 191 5 and 

 1 91 6 are wholly comparable and give one an idea as to the difference 

 in the relative prevalence of blackleg throughout Aroostook County dur- 



