240 POMOLOGY 



reflect light and heat, while a dark one absorbs it. Thus 

 the whitewashed trees were delayed a few days in their time 

 of blooming. He also shifted the resting period later in the 

 winter by later tillage and accomplished similar results. 



The heating and smudging of orchards are also used 

 rather extensively in some sections to ward off frosts and hold 

 the heat radiated from the earth. 



Laying trees and vines down during the winter and cov- 

 ering with earth or other material is also practiced to a lim- 

 ited extent, as well as baling trees up with straw or fodder. 



The important factor here, however, is the proper loca- 

 tion of the orchard. As indicated previously, high lands 

 are more immune to frosts than low ones, so that there is a 

 free movement of air and a drain of the cold air to lower 

 levels; also coves or pockets should be avoided. The slope 

 of the land is of some importance, particularly as the south- 

 ern limits of fruit-growing are approached, and also with 

 fruits that respond quickly to warm spells of weather oc- 

 curring early in the season. The southern and southeastern 

 slopes absorb more heat and hence trees often blossom some- 

 what earlier here than on the northern exposures. It is easy 

 to overestimate the value that can be gained by such a 

 selection, however. 



The following figures indicate the proportional amount 

 of heat received to a unit area by different slopes on June 

 21, at the 42d parallel north latitude:^ 



20° Southerly slope = 106 



Level = 100 



20° Northerly slope = 81 



One of the best known and in some respects most unique 

 cases of the effect of water on climate is seen in the Michi- 

 gan "fruit-belt." This is a strip of land from ten to twenty 



1 After Lyon, Fippin, and Buckman. Soils. New York. 1915. p. 318. 



