348 Fruit-growing in Arid Regions 



Management of Heaters. At first thought the care of 

 these heaters may seem to be a simple matter, but theie 

 is much to be gained in knowing just how to fire them. 

 It would be a better plan for the grower to attempt at 

 first to protect only a part of his orchard. And when 

 once the particular make of heater is decided upon and 

 bought, the grower should do a little experimenting on 

 his own responsibility and learn how to fire them to the 

 best advantage. This is especially true of coal burners. 



In orchards at least 25 per cent more heaters should be 

 placed around the borders than in the center of the block. 

 This is especially desirable when low temperatures are 

 accompanied by winds. As the heaters must remain in 

 the apple and pear orchard during the spraying season, an 

 effort should be made to place them where they will not 

 interfere with the passage of the spraying machine. It is 

 well to place the heaters at some distance from the trees. 

 The flaring-up of oil fires from the pot boiling over may 

 cause serious injury if the pots are placed too near the 

 trees. 



The number of heaters required per acre will depend 

 on the heater and other factors. No doubt orchards 

 with trees planted close together and large enough to 

 meet across the middles, as those shown in Figure 96, are 

 more easily protected than those with the trees far apart. 

 It is doubtful whether any of the heaters now manu- 

 factured should be recommended as ample protection at 

 a rate of less than sixty per acre. It is always best to 

 have ample protection, holding a number of the heaters 

 in reserve; and should winds accompany freezing tem- 

 peratures, it is much more effective to light a goodly 



