184 MAINi: AGRICUI^TURAL e;XPPE:RIME;nT STATION. I909. 



Under Maine conditions it is necessary to begin when the 

 tops are 6-8 inches high and spray every week or ten days till 

 the tops are killed by frost or the crop harvested. If weather 

 conditions are favorable, sprayings may be less frequent early 

 in the season, but not through August and September. If the 

 conditions are very threatening spraying at less intervals is 

 advised. Much loss from blight and rot results from too few 

 sprayings and stopping too early in the season. (P. 179.) 



Thorough spraying under very adverse weather conditions 

 has been found effective both in Maine and elsewhere. Thor- 

 oughly sprayed fields in Aroostook county in 1909 showed very 

 little loss from either blight or rot. (P. 180.) 



Much storage rot in 1909 resulted from infection at digging 

 time. If blight has not been kept off the foliage wait at least 

 ten days, if possible, after the tops are killed by frost before 

 harvesting. (P. 181.) 



Two other tuber decays occur but these were not contributing 

 factors in the two epidemics. (P. 182.) 



