338 Fruit-growing in Arid Regions 



inadequate. While spraying the plants would no doubt 

 prove effective and practicable in the case of the flower-bed, 

 it would not be practicable as a means of protecting the 

 orchard. Various plans have been employed for evaporat- 

 ing water into the air with the idea of holding the dew- 

 point above the freezing-point, but in the dry climates, 

 where the dew-point is normally far below the freezing- 

 point, such means of frost-fighting would avail little. 



Irrigation, like smudging, is an effective method of 

 frost-fighting when only a few degrees of frost may be ex- 

 pected, but it does not meet the requirements in most 

 places. When the grower is not prepared in any other way 

 to protect his orchard, it may be worth his while to turn 

 on the irrigation water. In doing this, however, he runs 

 the risk of forcing undue growth which may be more easily 

 injured by later frosts; and when once the water is turned 

 on, it generally puts a stop to all other means of frost- 

 fighting. It is almost impossible to work where irrigation- 

 water is running. The orchardist is to be warned that 

 irrigation will not avert injury from heavy frosts. In the 

 case of the strawberry-bed and garden crops, irrigation is 

 often a simple and efficient means of protection. 



Smudging 



Fighting frost by means of smudges has long been in use, 

 and while it has not always proved effective, it has many 

 advocates. The philosophy of smudging is to prevent the 

 radiation of heat from the ground by maintaining a blanket 

 of smoke over the area to be protected. In other words, 

 the idea is artificially to provide the protection of a cloudy 

 night. This cloud of smoke is provided by burning vari- 



