38 



ions on a variety to some one factor, as, for example, soil; 

 when as a matter of fact it may be due to a number of causes. 

 In general, we may say that there are four primary factors, 

 which affect the geographical distribution of varieties, 

 namely, temperature, moisture, soil, and parasites (includ- 

 ing insects and diseases). Many other secondary factors may 

 come into play; but they are essentially related to the four 

 factors mentioned above. Exposure, meaning the lay of the 

 land with respect to the points of the compass, and elevat- 

 ion are important factors in the adaptation of varieties. 

 Exposure may be important in securing protection from wind 

 or in allowing the fruit to take on a high color. 



The human element, or the "personal equation" should 

 not be lost sight of when we begin to count up the causes 

 why varieties may succeed or fail. The grower himself is 

 an important factor. One man writing from the Valley region 

 emphasized this point when he said: "With good care and cul- 

 tivation nothing hinders results; i have had six crops in 

 succession." 



The limitations of the variety, Albemarle, are well 

 known and often remarked upon. This variety requires good 

 elevation (1000 feet); generally it does not succeed at an 

 elevation of 500 feet. It delights in a deep rich, friable 

 soil j Porters black loam, which is a black soil, commonly 



