VEGETABLE GROWING 21 



by the tuber unit method in a row the second 

 season constitutes a progeny row. 



Under good cultivation yields of four hun- 

 dred bushels per acre are not at all uncommon 

 where high grade seed is used. Modern ma- 

 chinery has made it possible to handle the crop 

 on an extensive basis at a minimum of cost. 

 The gang plow, the potato planter, the riding 

 cultivator and the potato digger have all com- 

 bined to lessen man's labor in handling the crop 

 and to lessen the cost of cultivation. 



There are two distinctive potato industries 

 in the United States. One is the production at 

 the South of early potatoes for the great 

 city markets. This industry is of compara- 

 tively recent origin but has attained immense 

 proportions. Growers plant the crop early in 

 the season, generally using Northern grown 

 seed. This Southern industry, therefore, makes 

 a market for large quantities of seed potatoes 

 grown at the North. 



Another peculiarity of the industry is that 

 the tubers are harvested as soon as they are 

 large enough regardless of the stage of ma- 

 turity of either the tubers themselves or of the 

 vines. Potatoes of this character are highly 

 perishable and must be handled as quickly as 

 other perishable vegetable crops. These truck 



