26 AGRICULTURE OF MAINE. 



exposure to the direct rays of the sun for a few days, while the 

 Green Mountain varieties will only begin to turn a light green. 

 Exposure of a mixed lot of these varieties to the sun for a few 

 days will allow the farmer to pick the two varieties apart as 

 readily as though one were apples and the other potatoes. 



In the southern and central parts of the state, where there 

 is not so much danger of late frosts, it is safe to spread them 

 out of doors on the ground, but in Aroostook county this sun- 

 ning would have to be largely done in a building, with plenty of 

 windows to let in the rays of the sun direct upon the tubers, 

 as mere light will not bring out the difference of color in the 

 different varieties. 



While disease is causing a tremendous loss in yield to our 

 own growers and has caused a loss to the state of immense 

 sums, I feel sure that it has not caused us as much loss in our 

 seed trade as has varietal mixtures. There is no question but 

 that disease is cutting into the production of potatoes of Maine 

 to a much greater extent than many growers suppose. There 

 are several of these which are not so very serious, but each 

 will take its toll of loss in yield per acre, and the sum total 

 makes a very great reduction. Rhizoctonia, Blackleg and Bac- 

 terial Wilt are three, at least, to which a great many growers 

 pay but little attention, each of which cuts down the yield and 

 the sum total of the three makes the difference between profit 

 and loss to more fields than is generally supposed. 



Thirteen years ago I spent the summer carrying on potato 

 experiments at Caribou. At that time Mosaic was unknown 

 in the county, but has since spread over the whole state, there 

 being but few fields of the Green Mountain varieties in 191 5 

 which were free from it. It does not seem, as yet, to affect 

 the Irish Cobbler to any great extent ; but the Red Bliss, a 

 potato of similar vine growth, has been very nearly driven out 

 of the state by it. From my observation it is thought that there 

 are hundreds of acres of the Green Mountain varieties in 

 which the yield was cut down at least forty per cent the past 

 season by Mosaic alone. Many farmers suffering this loss did 

 not even know to what to ascribe their poor yield. This is one 

 of the diseases on which the growers need instruction and is 

 one of the hardest to control, with the present knowledge of 

 it. At present there does not seem to be any way of combating 



