CONTROL OF BI<ACKIvE:G DISEASE^ OF THE: POTATO.' 20/ 



gressive and uio-to-date farnaers in the State. They are very 

 famihar with the character and importance of the disease and 

 were intensely interested in the success of the experunents. 



These cooperative experiments were conducted by Mr. O. J. 

 Parsons, Patten ; Mr. O. L. Donaldson, Presque Isle ; Mr. J. F. 

 Hussey, Mr. Ira J. Porter, Mr. W. T. Good, E. Iv. Cleveland 

 Company, Mr. H. Edblad, and Mr. W. S. Blake, Houlton. 

 The writer takes this opportunity to express his appreciation 

 and thanks to these gentlemen for the careful and painstaking 

 manner in which they carried out their portion of the work, 

 upon which the . entire success of the experiment depended. 

 ■Collectively these gentlemen disinfected seed tubers sufficient 

 to plant 142 acres. Formaldehyde solution was used for 88 

 acres and formaldehyde gas for 54 acres. On the different 

 experimental fields taken together as large if not a larger area 

 was planted with untreated tubers. However, on some farms 

 only enough treated seed tubers were used to plant a few acres 

 while on others they were all treated except enough to provide 

 a check plot of suitable size. 



Methods Usfd in thf Coopfrativf Expfrimfnts. 



Before starting the experiments the writer conferred with 

 each individual experimenter and explained fully the methods 

 proposed and in all but one instance visited the potato houses 

 or farms and advised and assisted in starting the disinfecting 

 work. In addition a typewritten outline was furnished to each. 

 The following is a brief summary of this : 



The seed * used should come from fields where the disease 

 appeared the year before. In each case a check plot of un- 

 treated seed from the same source as the treated and selected 

 seed should be planted at the same time and on the same field 

 under identical conditions except for treatment. The different 

 plots must be plainly marked and labeled by proper stakes 

 driven into the ends of the rows. 



A part were requested to carefully sort out before disinfec- 

 tion all badly bruised or cracked tubers and all that appeared 



* The term "seed" is in common use in the potato growing sections 

 for potatoes used for seed purposes. Although botanically incorrect, 

 for convenience it will be so used in the following discussion. 



