WJiite Potato 



209 



The very heavy continuous yields of potatoes are largely a 

 question of the proper soil. 



Five to eight light surface tillings are required during 

 the season to save the moisture. Even after the vines have 

 begun to spread and to cover the ground, tillage may be 

 necessary in a dry year. 



Seeding. 



The size in which pieces of the seed tuber should be cut 

 has been the subject of much controversy, but the question 

 is easy of solution if careful and comparable experiments 

 are made. Arthur long ago showed (Proc. Soc. Prom. 

 Agr. Sci., 1891, p. 11; Bull. 42, Purdue Univ.) that the 

 unit in such tests should not be the number of eyes to the 

 piece, but the size of the piece. The piece contains food. 

 The more food the stronger the initial growth of the plant ; 

 and the stronger the initial growth, the better the crop, 

 other things being equal. But if the piece is too large it 

 contains so many eyes that there will be too many stalks to 

 appropriate the food and to struggle with each other. The 

 pieces on the tip or seed end " may contain several eyes, 

 but those from the other parts of the tuber usually should 

 contain only one or two eyes. Seed should not be cut any 

 considerable time in advance of planting unless it is rolled 

 in plaster to prevent excessive drying. 



The character of the crop depends greatly on the breed- 

 ing. Seed tubers should be taken only from productive 

 hills showing the qualities of the particular variety. 

 Choosing good-looking tubers from the bin is not a form of 

 plant-breeding; the selection should always consider the 

 pedigree. Breeding for resistance to disease is important. 



