CONSIDERATIONS OF SEED 69 



ting power for 36 plats is 73.8 per cent. Yet, here again 

 this does not convey a true impression, as on six plats 

 all of the tubers germinated, and the table shows that 

 there is a greater chance of securing a stand of between 

 83 and 98 per cent, than lower. 1 



The viability of tubers is injured or ruined if they 

 heat or sweat to any extent; hence, if they have been 

 treated with a solution, as for scab, it is essential that 

 they be planted at once or spread thinly to dry. Po- 

 tatoes may be ruined for seed purposes, if frozen, or if 

 shipped in bags or barrels which have contained sub- 

 stances injurious to the buds as, sugar, nitrate of soda, 

 etc. ; and even moving them on the farm in unwashed 

 sugar-bags has been found to be dangerous. Immer- 

 sion in water for more than a day may destroy the 

 buds, and probably cause the tuber to decay in a few 

 days. By this means potatoes have been destroyed in 

 pits and in the field when floods have occurred. Soak- 

 ing them in too strong a solution of formalin or other 

 preservative is liable to reduce viability, because the 

 formalin tends to preserve the tuber and prevent its de- 

 composition. 



Potatoes which have been subject to diseases may be 

 weakened and their vitality impaired. 



1 From data in Ohio Kxp. Sta. Bui. 145, p. 21. 



