82 



Nature-Study Agriculture 



Protecting 

 orchard 

 trees from 

 frost 



die. The manner of 

 pruning a peach tree 

 until it is ready to bear 

 is shown in Figures 61, 

 62, and 63. 



After a fruit tree is 

 given the desired shape 

 by the first few years of 

 pruning, it needs little 

 attention other than to 

 be kept from growing 

 I so many branches as 



^j&F ^spile to crowd the fruit or 



' keep out the sunlight 

 (Fig. 63). Any dead 

 branches should be 

 trimmed out. 



There are a few weeks in early spring when fruit 

 buds are liable to be injured by frost. Many orchardists 

 have stoves ready to light on frosty nights. The tem- 

 perature of an orchard may be raised several degrees 

 by these outdoor fires (Fig. 65). 



An orchard on low ground*is in much greater danger 

 of being injured by frost than is one on high ground 

 (Fig. 66). Cold, like water, flows to the bottom of a 

 valley. A sharp narrowing of the walls of a valley, or 

 a grove of tall trees within it, will check the flow of 

 air as water is checked by a dam. Such a place, where 

 cold air cannot drain away, is badly chosen for an 

 orchard. (Exp. 10.) 



If a tree is injured by animals or disease or by being 



FIG. 60. 



U. S. D. A. 



Peach tree six months after 

 planting. 



