10 The Principles of Fruit-grovring 



good economic units. The lesson is that mixed industries 

 are best for any community, even though the region make 

 a specialty of one or of a few commodities, and that it is 

 practically impossible to reduce the agriculture of any 

 large region to a dead level of uniformity. The diversity 

 , of industries also brings a diversity of population. 



In the present development of the newer parts of North 

 America, however, these stages in the evolution of fruit- 

 growing may not be marked. Fruit has now come to be 

 such a standard commodity that virgin areas in newly 

 opened regions may be developed at once as fruit lands; 

 but there is a large element of risk in such tindertakings 

 in virgin regions. 



THE DETEKMINANTS IN FRtriT-GEOWING 



Fruit-growing, in common with all agricultural pur- 

 suits, thrives best in certain geographical areas. That is, 

 the business is not capable of equal development in all 

 parts of the country. 



Four of the most apparent determinants of the distri- 

 bution of fruit-'growing may be mentioned briefly. The 

 distribution of fruits may also be studied in their relations 

 to life-zones, and particularly as determining the adapta- 

 bilities of varieties (see for example. Bull. No. 10, Div. of 

 Biol. Surv., U. S. Dept. Agric, 1898, by C. Hart Merriam, 

 on "Life Zones and Crop Zones," as one of the early con- 

 tributions to the subject). The leading determinative 

 factor in the distribution of fruit-culture is cljjoate. The 

 particular factor of climate that determines the fruit- 

 zones differs with each type group of fruits; but in gen- 

 eral it may be said that the relative annual temperature is 

 the most influential factor. 



