ECONOMIC CONSIDERATIONS 47 



quickly should not perhaps be sprayed with Bordeaux 

 mixture. 



This subject is fully discussed, and accompanied by a 

 voluminous quotation of literature bearing on the subject, 

 by Dr. Fairchild, in Bull. No. 6, U.S. Department of 

 Agriculture. 



ECONOMIC CONSIDERATIONS 



In attempting to furnish statistics bearing on the subject 

 of loss owing to plant diseases, or the gain resulting from 

 the use of preventive and remedial measures in combating 

 these pests, it is with regret we have to admit the fact 

 that it is necessary to search the literature of other nations 

 for information. 



In Tubeuf and Smith's Diseases of Plants (Engl, ed.), 

 p. 84, we find the following account : — 



' In the Zeitschrift fiir Pflanzenkrankheiten^ 1893? the 

 International Phytopathological Commission gave, from 

 estimates furnished by the Prussian Statistics Bureau, a 

 review of the losses in Prussia from grain rust. Amongst 

 other estimates we find that in 1891 the wheat harvest 

 of Prussia reached a total of 10,547,168 doppelcentner 

 (i doppelcentner = 100 kilogramme), which at 22 marks 

 per d.c. = ^11,459,690 sterling. Of this 3,316,059 d.c, 

 o^;£^35593j758, was depreciated by rust. The rye harvest 

 was 30,593,758 d.c. at 22 marks, of which 8,208,913 d.c, 

 or ^^8,896,364, was depreciated by rust. Oats reached 

 32,165,473 d.c. at 16 marks, of which 10,325,124 d.c, 

 or ;£8, 1 38,023, falls to be deducted on account of rust. 

 Thus on the crops, wheat, rye, and oats, the loss reached 

 the sum of ^20,628,147 sterling, or almost a third of 



