SPRAYING AND SPRAYING APPARATUS. 



125 



the liquid is forced out with each stroke. This method works 

 quite well while the pump is new and the packing tight, but as 

 the pump becomes worn it will usually be found that all of the 

 liquid which the cylinder will handle will be needed in order to 

 maintain sufficient pressure. Moreover, the hole through which 

 the jet escapes wears larger in time and thus further helps to 

 decrease the efficiency of the pump. 



Agitation In Tank Outfits. All tank outfits should be equip- 

 ped for agitation for all kinds of spraying compounds. It is, 

 however, desirable not to have the agitation too violent, be- 

 cause with some spraying compounds, especially with the lime- 

 sulfur wash, there may be considerable sediment which, while 

 small enough to pass through the strainer on the suction hose 



and through the nozzle in 

 small quantities, may in 

 larger quantities cause con- 

 siderable difficulty with 

 these parts. The agita- 

 tion should be just sufficient 

 to keep the finer particles in 

 suspension and still allow the 

 coarse particles to settle. One 

 way of providing agitation is 

 to have the tank sectioned 

 crosswise with partitions 

 every two and a half or 

 three feet, leaving a hole 

 about a foot wide and six 

 inches high through which the 

 liquid will rush and cause a 

 general stirring up every time 

 the wagon is driven forward 

 does well with small 

 well made Bordeaux and 

 but where they tend to 



Fig. 56. Plum leaf covered with 

 arsenate of tead after 10 days. 

 Showing how well it sticks 

 to the foliage, 

 another tree. This method 



to 



to medium-sized trees with 



the lighter spraying compounds 



settle rapidly, such agitation is seldom sufficient, and where the 



trees are so large that considerable periods occur between 



movements of the wagon it is entirely insufficient. Another 



objection to this method is that the partitions make it difficult 



