SPRAYING PROBLEMS 



Why has the question of spraying become of such 

 prominence to-day that it is numbered among the 

 biological war problems to be discussed in this series 

 of lectures? Spraying, as everyone' knows, especially 

 when conducted on a national scale, entails a demand 

 for supplies supplies of machines, chemicals, labour, 

 &c., at a time when the nation needs to economize- 

 why, then, does the production of these things come 

 under the category of the essential war industries? 

 Since the nation was as wholly unprepared for ex- 

 tensive spraying as it was for the infinitely larger 

 schemes of conscription and food rationing, the reason 

 must be a sound one. 



The answer is readily given: spraying is, in the 

 first instance, an important means of obtaining an 

 increased production of food, and, in the second place, 

 it greatly assists to economize our produce. 



Spraying is a means of attack used in the war 

 against pests of animals and plants. These pests are 

 numerous, and attack nearly every kind of plant, but 

 their ravages naturally become most serious where 

 plants of one kind are aggregated, as in the case of 

 crops and orchards, since here the conditions are 

 most favourable for epidemics. These pests, in their 

 quest for food, often cause immense damage, and 

 through their persistent and repeated raids the culti- 

 vation of certain economic plants in several instances 

 has been abandoned. 



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