288 



Journal of Agricultural Research 



Vol. XX, No. 4 



Table IV. — Distribution of diseased plants 

 OBSCURE DISEASE GROUP 



HEALTHY GROUP 



PARASITIC DISEASE GROUP 



12 



13 



14 



15 



16 



17 



18 



19 



Total.. 

 Grand total 



23 



5 



484 



125 



28 



15 

 96 

 61 



837 



3,492 



46 

 10 



1, i3 6 



272 



56 



30 

 214 



150 



1,914 



7,93° 



"3 

 56 

 19 

 10 

 40 

 3i 



270 



i,475 



1 

 197 



74 

 17 

 4 

 37 

 45 



377 



i,93i 



5 2 

 41 

 14 

 3 

 17 

 23 



150 



96 



34 



3° 



121 



63 



17 

 52 

 45 



458 



1,789 



13 

 13 

 11 



75 



41 

 13 

 25 

 14 



205 



955 



93 



3° 

 32 



145 

 62 



15 

 74 

 39 



490 



2,3*5 



13 



14 



8 



9i 

 3i 

 4 

 25 

 26 



1,404 



The figures given in Table IV indicate no conspicuous relation between 

 the character of the tuber used for seed and the occurrence of disease, 

 since the number of pairs of diseased plants is only equal to from one-half 

 to one-third the total number of diseased plants in either locality. It is 

 to be noted that in general the Colorado conditions resulted in more dis- 

 ease than did those of Wisconsin, particularly when cut seed was used, 

 and this, too, notwithstanding the fact that the cut tubers were well 

 suberized when planted. 



