94 



POPULAR FRUIT GROWING. 



is not enough to make up for the difference in efficiency. How- 

 ever, it may become of much importance in the case of hilly 

 land. Here the light dust spray outfits can be used when it 

 would be impossible to get around with a barrel of liquid spray, 

 or, much less, with the large wagon outfits. 



Liquid Spraying Outfits. Pressure. The important point 

 in the application of liquid sprays is to get a high pressure. 

 This should not be less than 75 pounds on an ordinary pres- 

 sure gauge. For high trees better work will be accomplished 

 with a pressure of 125 pounds. It is not usually advisable to 

 use a pressure of over 125 pounds, because it is too hard on 

 the machinery and apparatus in general. The higher the pres- 

 sure it is practicable to maintain, however, the more eflicient 

 will be the application of the spray. This should be applied 



in the finest mist-like form pos- 

 sible, and a good pressure is nec- 

 essary to accomplish this. A fine 

 mist will float among the foliage 

 like a fog if there is not too stiff 

 a breeze, and will cover both sides 

 of the leaves and fruit much bet- 

 ter than could possibly be the case 

 with a spray of drops such as comes 

 from an ordinary nozzle under low 

 pressure. 



Agitation in Barrel Outfits. 

 The movement of the barrel while 

 in use is often sufficient to keep 

 well made Bordeaux and other 

 light sprays from settling, but with 

 the heavier sprays, like Paris Green and lime-sulfur wash, 

 some provision for agitation is necessary. Probably the best 

 way to provide for this agitation is to have a paddle attached 

 to the pump near the bottom of the barrel in such a manner 

 that it will move with every stroke of the handle and thus keep 

 the liquid stirred up and prevent settling. Another method of 

 providing for agitation, known as "jet agitation," is to leave a 

 small hole in the bottom of flie cylinder, through which a part of 



Fig. 41. Knapsack spray- 

 er. 



