TWO EPIDEMICS OF POTATO BLIGHT AND ROT. l8l 



rot. Other well sprayed fields nearby were equally well pro- 

 tected. The plots at Foxcroft which had 6 double sprayings 

 gave 0.6 per cent of rot while those at Houlton showed 9.1 per 

 cent. There is no doubt that equally good results might have 

 been obtained on nearly every field in Aroostook county in 1909 

 if they had all received as thorough spraying. In fact a few 

 cases, particularly in the vicinity of Houlton, were found where 

 spraying had been thoroughly done. Here the foliage was fully 

 protected through the season and little or no rot was found on 

 digging. Though dug early, two of these lots showed no rot 

 and one other a slight amount after about three weeks of 

 abnormally warm weather in storage. 



These demonstrations that thorough spraying with bordeaux 

 mixture will give entire protection from the ravages of late 

 blight are by no means new in Maine. Nine years ago Director 

 Woods of this Station secured with four sprayings at Houlton 

 increased yields valued at over $40.00 per acre at the current 

 price of potatoes at an estimated expense of $2.50 per acre.* 



DECAY IN STORAGE I9O9. 



The season of 1909 in Aroostook county demonstrated again 

 on a large scale what has previously been shown to be true 

 experimentally, namely ; that where potatoes are blighting it 

 is unsafe to dig and store the crop for at least ten days after 

 the tops are killed by frost, and even a longer delay will do no 

 harm.** 



The crop on many fields where the blight had secured more 

 or less of a foothold was dug early in September. In many 

 cases these tubers were practically all sound when dug but the 

 blighting leaves were producing spores abundantly which were 

 showered on the potatoes. These potatoes on account of the 

 excessive rains came out of the soil wet and in most cases were 

 not allowed to dry off before being picked up and placed in 

 barrels, thus furnishing ideal conditions for infection by late 



* Woods, C. D. Me. Expt. Stat. Bulletin 112 pp. 2-5 (1905). 



** Jones, L. R. and Morse, W. J. Repts. Vt. Exp. Sta. 15, pp. 219- 

 223 (1902); 16, pp. 161-163 (1903)- 



See also Proceedings Society for Promotion of Agricultural Science 

 (1904). 



Woods, C. D., Me. Expt. Stat. Bulletin 112, pp. 2-5 1905). 



