252 AGRICULTURE OF MAINE. 



This season, what appeared to be a new type of potato trouble 

 suddenly manifested itself in midsummer in various parts of 

 Maine. Apparently this is, in part, intimately associated with 

 soil conditions and we were able to make immediate progress 

 in the study of it on account of the active cooperation of the 

 chief of the soil fertility investigations who came here and gave 

 the matter his personal attention for several days and detailed 

 two members of his stafif to make a special study of these 

 phases of the problem. 



Potato Mosaic. 



In the discussion which follows, no attempt will be made to 

 describe in any detail the disUnctive characters of the diseases 

 under consideration, for this would be impossible in the time 

 at our disposal. Most of them are fairly well illustrated by 

 means of photographs and preserved specimens now on exhibit 

 in the hall. 



Mention has been made of the mosaic disease, a potato 

 trouble which manifests itself in the form of a peculiar mot- 

 tling and crinkling of the foliage. Its economic importance is 

 due to the fact that where it occurs in any appreciable amount 

 the evidence is fairly conclusive that the yields are materially 

 reduced. While, as yet, no active parasite has been found 

 associated with it, mosaic is carried with the tubers, and once 

 it gets started in a given strain of seed it often gets worse, in- 

 stead of better, in spite of all that can be done. The Irish Cob- 

 bler appears to be free from it in Maine, but it is becoming 

 more and more apparent each year on the Green Mountain, and 

 the Red Bliss is so susceptible that it is now very difificult to 

 find a field of this variety which is free from it. 



Both the Department and the Station are giving special at- 

 tention to potato mosaic and it is hoped to concentrate pretty 

 strongly upon it during the next few years if it continues to 

 prove threatening. The Department workers have been coop- 

 erating with Commissioner Wortley of Bermuda, who spent 

 some time in Maine last summer, in trying to eliminate mosaic 

 from the less badly alTected fields of Bliss, by roguing the 

 diseased plants as fast as seen. While this is undoubtedly bene- 

 ficial, the prospects of entirely eliminating the disease in this 

 way or even preventing its increase are, from my limited 



