44 



INSECTS INJURIOUS TO VEGETABLES 



order and therefore do not last longer than a season or two. 

 The want of an instrument to fulfill modern requirements for 

 a Hue spray is met by various manufacturers in the form of 

 knapsack sprayers, bucket pumps and barrel spray pumps. 



The spray is obtained by a hose attachment and different 

 forms of nozzles, of which the vermorel type is the best. 



The knapsack sprayer is a copper tank made to be strapped 



Fig. 22.— Knapsack sprayer 



on the back of the operator (fig. 22). Within there is a small 

 pump which is operated with one hand while the nozzle is held 

 in the other. The handle may be removed, if desired, and the 

 tank carried by hand instead of on the back. The cost is from 

 $9 to $18. It is good for gardens and for moderate-sizfed plats 

 on truck farms. Of its usefulness Mr. M. B. Waite, a 

 pathologist of the United States Department of Agriculture, 

 says in substance : 



The barrel pump has nearly driven out the knapsack outfit 



