78 THE POTATO 



disease germs. The killing of weeds before the 

 seed is planted makes the cultivation of the grow- 

 ing crop easier, and the constant stirring and work- 

 ing of the soil that kills the weeds aerates and 

 makes possible sun action that kills spores and 

 germs of disease/ On Mt. Sopris Farm the soil is 

 often worked six, seven, and eight titaes before 

 planting. When the good results that are accom- 

 plished in the preparation are continued by deep 

 cultivation closely following planting, a splendid 

 crop is, in most instances, assured. 



Where soils are badly infected with disease 

 germs it is best to rotate the potato crop with 

 grains and grasses. George Sinclair, farm man- 

 ager of the Earl of Rosebery's Dalmeny Farms, 

 a prominent British agriculturist, says that one 

 year in grain and three in sod will free soils of most 

 potato diseases, and that this practice will make 

 possible the continual growing of big crops. 



When crops are to be grown in succession it is 

 found advantageous to open up the furrows in 

 which the potatoes are to be planted and let the 

 sun and air disinfect them for a day or longer 

 before planting. 



In the Twin Falls country in southern Idaho, 

 or elsewhere throughout the mountain valleys of 

 the Northwest, potatoes make the greatest yields 

 on alfalfa or clover sod. It is always best to grow 

 them in a crop rotation so that not more than two 

 crops are raised in succession on the same land. 

 Growing potatoes puts ground in excellent tilth for 

 grain, because the thorough cultivation makes 

 large quantities of plant food available for the 

 rootlets of the grain plants. One of the most suc- 

 cessful crop rotations practised by the best growers 

 is three years of alfalfa or clover, the last cutting 



