POTATO SCAB 



103 



for both. As above, the untreated plots gave 48 per cent, of 

 scabby potatoes and 53 per cent, scab-free. The plots treated 

 with the stronger solution of formaline gave 13 per cent, 

 scabby and S'J per cent, scab-free ; a gain of 35 per cent, in 

 favor of the treatment. The plots treated with the weaker 

 solution gave scabby, 21 per cent., scab-free, 79 per cent. ; a 

 gain of 27 per cent, in favor of the treatment. These results 

 indicate that formaline is an effective remedy for the scab, and 

 in the strengths used above rivaling corrosive sublimate. It 

 possesses advantages over corrosive sublimate in being less 

 poisonous and more easily applied, but with the data at hand 

 we are not yet ready to recommend its substitution for that 

 remedy. 



Itifiuerice of Different Fertilizers on Development of 

 Scab. — The following table summarizes the results of experi- 

 ments in regard to this point. The experiments with different 

 fertilizers were crossed with those on the treatment of the scab 

 on the same plots. . 



Field A. 



Field B. 



Previously 

 reported. 



® 



a 



t3 



Phosphate. 



Scab free. 

 Scabbv 



63 

 37 



Wood ashes. 



Scab free. 

 Scabbv — 



70 

 30 



34 

 66 



95 

 5 



28 

 72 



90 

 10 



59 

 41 



No fertilizer. 



Scab free. 

 Scabbv 



90 

 10 



73 

 27 



95 

 5 



81 

 19 



