368 The Principles of Fruit -growing. 



purposes, and the like, they are exceedingly useful 

 and handy. The syringe and bucket purnps are 

 very efficient for work upon a small scale, and 

 especially when it is desired to be extra thorough. 

 The greatest difficulty with the bucket pump is that 

 the amount of material which can be carried is very 

 small. The power sprayers (those which work from 

 the wheel of the vehicle) are useful for vineyards, 

 dwarf pears and low- growing plants ; but, as a rule, 

 they are not adapted to large orchard trees, because 

 enough liquid cannot be thrown whilst the machine 

 is passing a tree to thoroughly spray it. For very 

 large areas and very tall trees (as street trees) steam- 

 power sprayers are coming into use. 



7. The farmer should know what he icants to kill 

 before he begins to spray. It is common to find a 

 man who is going at spraying with enthusiasm, but 

 who cannot explain a single definite object which 

 he has in view. He simply knows upon general 

 principles that spraying is useful. To such a man, 

 spraying is spraying, whether he uses Paris green, 

 or Bordeaux, or both, or neither one; and his results 

 are about equal to his knowledge. There is no 

 longer an excuse for such ignorance, for all the lead- 

 ing insects and fungi have received more or less 

 exact treatment in the publications of the experiment 

 stations. The state of knowledge is far in advance 

 of the state of practice. Many fruit-growers demand 

 such elementary instruction as this: 



The arsenites (Paris green and London purple) 

 are used to kill all larvae or worms, and all those 



