Orchard Heating 265 



hectares (about 2,200 acres) — namely, at a cost of 25 cen- 

 times (5 cents) for each 2J4 acres. The illustration 

 (Fig. 95) shows the Lestout method in operation. In 

 North America, the direct heating of plantations is now 

 gaining the ascendancy over smudging. 



One of the advantages of a smudge is the utilization 

 of it very early in the morning to protect the plantation 

 from the sun when the night has been very cold and there 

 is reason to think that the buds have been injured. All 

 frosted plants should be protected from the sun on the 

 chance that they may recover. 



Heating the plantation. 



It is possible and in many cases practicable to heat 

 the fruit-plantation by means of fires, even raising the 

 temperature as much as 10°. Preparation is made in 

 advance, and when the indications point to frost, the 

 fires are lighted. The smoke arising from the fires may 

 combine the effects of a smudge with the heating of the 

 air, although little dependence is commonly placed on 

 the smoke. In very recent years, the heating of plan- 

 tations has assumed commercial importance, particularly 

 in Colorado and on the Pacific slope, and many heating 

 devices are now on the market. 



Any combustible material may be used, as wood, straw, 

 leaves, shavings, manure, prunings from the plantation, 

 coal and oil. The manure and straw are more useful for 

 smudging, but the use of wood — as cordwood, old rails, 

 stumps, and general refuse — is wholly practicable; the 

 material to use is largely a matter of cost. The patented 

 oil-burners are compact and effective; and it is now gener- 

 ally considered that crude-oil or distillate is the best and 

 most economical material to use. 



