14 BULLETIN 82, U. S. DEPAETMENT OF AGEICULTTJBE. 



SACKS AND BARRELS AS AGENTS IN SPREADING POWDERY SCAB. 



It is well known that secondhand sacks, barrels, and boxes are 

 often used in marketing potatoes. 



Seed potatoes shipped from the Northern States to be grown in the 

 South are put up either in sacks or barrels. European potatoes com- 

 ing to this country are shipped in 168-pound gunny sacks. In some 

 of the Western States similar sacks, but holding only 120 to 150 

 pounds, are used. These sacks cost from 12 to 16 cents each, depend- 

 ing upon their quality and whether they are new or secondhand. 

 Sacks of good quality can be used many times, and this has come to be 

 common practice. In both New York and Boston there are firms 

 that act as clearing houses for jDotato sacks, buying secondhand sacks 

 from anyone who may wish to sell them and shipping them to potato 

 dealers either north or south. It may happen, therefore, that sacks 

 that have previously contained diseased tubers coming from Europe 

 or elsewhere will be used for shipping select seed from the North to 

 the South. It is not improbable, and, indeed, very possible, that 

 spores of Spongospora, Spondylocladium, Fusarium, Phytophthora, 

 etc., may be communicated to healthy potatoes through secondhand 

 sacks. The same thing may take place through using secondhand 

 barrels, but this is not so often done. There is, however, considerable 

 chance of potato diseases being spread by means of old sacks. 



The question arises as to how this spreading of disease can be pre- 

 vented and, of course, the solution is a simple one — by using only 

 new sacks. But this would increase to some extent the cost of pota- 

 toes and bring about the accumulation of large quantities of old sacks. 

 It seems very likely that some means of sterilizing old sacks could be 

 put into practice which would make them fully as harmless as agents 

 in disseminating diseases as new sacks. This could probably best be 

 carried out by firms dealing in sacks. It seems probable that sub- 

 jecting the sacks to steam sterilization for several hours at a pressure 

 of 15 to 20 pounds would render them free from noxious diseases with- 

 out increasing their cost to any appreciable extent. 



