The BuLLETiisr. 37 



it settles to the bottom of the liquid quickly unless constantly stirred, and 

 does not give so good results. Use about lA pound to 50 gallons. 



Arsenate of Lead is less known, is not so commonly sold, costs more to 

 make the needed treatments ; but it does not "burn" the leaves or fruit, 

 it holds up well in the spraying liquid, sticks longer to the foliage, and 

 gives actually better results. Experienced growers who spray now de- 

 pend almost wholly on the arsenate of lead. A number of larger drug 

 or hardware firms in our more important towns are now handling arse- 

 nate of lead. 



Arsenate of lead is sold in two different fonns : as a thick paste and 

 as a dry powder. At this writing the paste form is the more common, 

 but the use of the poAvdered form is increasing. As about one-half of 

 the Aveight of the paste form is water, it is necessary to use only one-half 

 as much, by weight, of the powdered form as of the paste form. 



For apples use 3 to 4 pounds of the paste form of arsenate of lead to 

 50 gallons of spray, or li/o to 2 pounds of the powdered form. 



For peaches use 2 to 21/2 pounds of the paste form to 50 gallons, or 

 1 to 114 pounds of the powdered form. 



We are often asked if the paste form can be used after it has become 

 considerably dry and hardened. In our OAvn work we have used this, but 

 using a somewhat less amount by weight (depending upon the degree of 

 dryness) and using special pains to see that it is all reduced to liquid in 

 the spray solution, by working it into a moist lump in the hands and 

 gradually working it in the liquid in our hands until it all dissolves out 

 between the fingers, then stirring thoroughly and straining carefully. 



THE USE OF OIL AND SOAP SPRAYS. 



While we give general preference to sprays of Lime-sulphur and Bor- 

 deaux Mixture, yet there are many growers who prefer sprays containing 

 soaps or oils, especially for winter treatments to control the San Jose 

 Scale. There are a number of manufacturers who sell ready-made oil or 

 soap sprays which are prepared merely by adding water. (See discus- 

 sion of "Soluble Oils" and "Whale Oil Soap," on page 20.) 



The oil and soap Avashes have the advantage that they are more pene- 

 trating than lime-sulphur, and on apple this is an especially good point, 

 as the small twigs are often so fuzzy as to hinder the lime-sulphur from 

 reaching all the scales. Also, there is less corrosion and clogging of the 

 pumps. But, on the other hand, there is some danger to the trees (espe- 

 cially peach) if the soaps or oils are at all carelessly used, and they do 

 not seem to have quite so much effect on the fungous diseases. 



Kerosene Emulsion. — This was once the standard remedy for all kinds 

 of scale insects and for most plant lice, and though it has been replaced 

 by the Lime-sulphur Wash as a remedy for San Jose Scale, it is still 

 used by some growers for treatments in spring or summer, when the reg-u- 



