38 HORTICULTURAL MANUAL. 



the commercial orchards of southwest Iowa, Missouri, and 

 indeed westward to Arizona. On the prairies an elevation 

 of only twenty feet above the general level is a signal 

 advantage in orcharding. It not only gives comparative 

 exemption from frosts in spring, but it usually gives better 

 soil conditions as to porosity and drainage, and even com- 

 parative exemption from blight and fungus troubles. 



With the small fruits lower positions are sometimes best 

 on account of increased moisture. But in many cases the 

 greatest success attained on the relatively low land comes 

 from the fact that still lower levels are adjacent giving 

 fair air-drainage. 



42. Fruit Soils. Perhaps there is not a settled area in 

 the United States where certain varieties and species of 

 the fruits may not be grown with reasonable care. Even 

 in the arid States the conditions of soils are usually favor- 

 able where water for irrigation is obtainable. But com- 

 mercial fruit-growing sooner or later springs up on soils 

 not too compact, and with jointed clay or other kinds of 

 porous subsoil below. In California the orange reaches 

 its highest perfection on the slopes where the mountain 

 wash has given porosity to the subsoil. In the arid States, 

 Arkansas, Missouri, and the States bordering on the 

 Missouri the present commercial fruit centres are on land 

 that will permit the descent of water in a wet time, and 

 its rise by capillary movement in a dry time, if needed 

 culture is given. It is the same with the fruit centres of 

 Michigan, New York, and the selection of soil for the 

 great peach-orchards in Georgia. At the great expositions 

 of the past fifteen years the finest specimens of given 

 varieties of fruits have come from the orchards with most 

 favored soils and subsoils, combined with culture and 

 cover-crops (19). 



43. Fruits as Modified by Climate. Heat and light 



