POTATOES 127 



bank, Irish Cobbler, Carmen No. 3, Rural New Yorker, Early 

 Triumph, and Sir Walter Raleigh. Experience only can deter- 

 mine the most suitable variety for a given locality. The four- 

 hill-unit method of improving potatoes described in Chapter 

 XIV is well worth trying. In a few years a high-yielding strain 

 adapted to local conditions may be developed in this way. 



Individual tubers, to be used for seed, should have a smooth 

 skin, shallow eyes, good shape, and should be free from evi- 

 dence of disease, such as scab. Blocky, rather than long, 

 pieces should be cut. Each piece should contain one or two 

 eyes. The size of the piece is more important than the number 



tUt 



Potato tubers the kind for initial selection in the four-hill-unit method 

 of improving potatoes by selection. 



of eyes. A one-ounce piece will furnish plenty of plant food 

 to give the new plant a good start. 



A sandy loam underlaid with clay is regarded as the best 

 soil for potatoes. It should be moderately rich, especially 

 in organic matter, for the double purpose of providing good 

 soil conditions and plant-food material. The soil should be 

 kept in good condition by rotating the potatoes with legumes 

 and the frequent use of green manure. Other fertilizers are 

 also needed, especially potash, and some phosphoric acid. 

 The potash and phosphoric acid requirements may be met 

 by using a heavy application of manure reinforced by acid 

 phosphate. 



