48 The Fruit-Growers Guide-Book 



CHAPTER II 



Orchard Heating 



Every orchardist is agreed that spraying is an absolute 

 necessity in order to produce fruit free from the defects 

 caused by insects and fungi. Yet spraying as a commer- 

 cial proposition is of only recent adoption, dating no 

 farther back than 1872, when Le Baron, the state entomol- 

 ogist of Illinois, found that Paris green would control the 

 potato beetle. Spraying began to be of commercial value 

 in 1885 when the effectiveness of copper sprays was dis- 

 covered by the vineyardists of France. Yet there is a 

 still newer practice, viz: orchard heating, which is bound 

 to take rank on a par with the practice of spraying as a 

 means of securing crops of fruits against an unfavorable 

 environment. 



New Idea 



Orchard heating as a commercial proposition is of very 

 recent origin, although for many years fruit men and 

 gardeners- have tried various plans of preventing frost 

 from injuring their plants and blossoms. Some of these 

 attempts was by keeping the trees sprayed during the 

 winter with whitewash, under the belief that since the 

 whitewash would reflect much of the sun's rays the wood 

 of the trees would not get so warm during sunshiny days 

 of winter, and hence retard the development of the fruit 

 buds. However, such methods in practice would hold the 

 buds back for only three or four days behind those trees 

 which were not sprayed, while the danger period in spring 



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