102 MAINE AGRI CULTURAL, EXPERIMENT STATION. I914. 



actually increases the virulenoe of the 'disease. In the same 

 series of articles this writer has given results which indicate that 

 sulphur is of considerable value for soil treatment. 



There is every reason to believe that the presence of powdery 

 S'caib in Maine has been detected in time so that it will be possi- 

 ble to prevent its farther spread and possibly to eventually en- 

 tirely eradicate it. However this can only be done through the 

 cooperation and concerted action of all parties interested. In 

 the section where the disease occurs no land should be replanted 

 to potatoes in 19 14 unless it is shown beyond doubt that the 

 19 1 3 crop was free from powdery scab. For the coming year no 

 seed stock should be used unless it is known to be free from 

 contamination. Land known to be infected should not be used 

 for potatoes again till more data has been accumulated with 

 regard to the length of life of the organism within the soil. 



No potatoes should be planted withouit first disinfecting them 

 with forma:ldehyde or corrosive sublimate, for if by chance the 

 healthy seed has becoime contaminated this would tend to elimi- 

 nate the danger from this source. In fact there are many argu- 

 ments in favor of planting no potatoes whatsoever without first 

 disinfecting them. By careful selection of only sound, thor- 

 oughly healthy seed tubers, and then disinfecting it is possible 

 to entirely eliminate blackleg, prevent the spread of ordinary 

 scab, and also to overcome some of the losses from seed decay 

 and so-called imperfect germination. There is no doubt that if 

 careful selection of seed, along with disinfection had been gen- 

 erailly adopted by our potato growers, and rigidly carried oat 

 in the past powdery scalb, 'blackleg, etc., would not have gained 

 a foothold in the State. 



After the sound, healthy seed tubers have been disinfect:td 

 great care should be taken not to contaminate them by allowing 

 them to co'me in contact with, sacks, barrels or planters, etc., 

 which may carry the germs of the disease. 



Disinfection of Seed Potatoes, Implements and Storage 



Houses. 



Many inquiries have been addressed to this Station asking 



for information as to the best method of disinfecting seed 



potatoes, implements and storage houses for powdery scab. 



As already stated only a comparatively small amount of atten- 



