MONTANA EXPERIMENT STATION. 223 



2. Kerosene emulsion, one-third kerosene. 



3. Kerosene emulsion, one-fifth kerosene. 



4. Sulphur and lime wash, 1-1-2. (One pouiul sulphur, one pound 

 lime, two g'allons water.) 



5. Sulphur and lime, 1-1-4. 



6. Suli)hur and lime, 1-1-8. 



7. Crude petroleum emulsion, 10 per cent, strength. 



From the results of his experiments Prof. Aldrich drew the fol- 

 lowing conclusions : 



"Crude petroleum could not be uniformly applied. The emulsion 

 was very unstable, and the oil is much too thick to apply pure. No 

 damage resulted to Ihe trees, but in many cases the eggs of lice 

 were not destroyed. 



Pure kerosene &fj"iou?ly injured the trees to which it was applied, 

 but killed all the eggs. 



Kerosene emulsion of one-third strength injured the foliage to 

 some extent, though not very seriously ; it did not kill the eggs with 

 any uniformity, in one-fifth strength it did not injure the foliage, 

 but was ujt at all etfective in killing the eggs. 



Sulphur and lime did not injure the foliage in the least, however 

 strong. In the 1-1-2 and 1-1-4 proportions it killed almost all the 

 eggs; it is a cjuestion whether the very few that hatched had not 

 been missed by the spray. 



Of the seven kinds of spray used, the choice for commercial pur- 

 poses would undoubtedly be No. 5, sulphur and lime in the 1-1-4 pro- 

 portion, or what is called the "Piper formula." 



1-1-4 proportion is probably a successful winter treatment, it will be 

 applicable only on small trees that can be closely examined and thor- 

 oughly sprayed. 



In conclusion, we recommend that Montana apple growers make 

 careful, conclusive tests of the 1-1-4 lime-sulphur wash as a winter 

 treatment, and mean while place their main dependence on the use 

 of kerosene emulsion and whale-oil soap or quassia-whale oil soap 

 solution, spraying trees that are generally infested and dipping the 



He further concluded that while the lime-sulphur wash in the 

 extremeties of limbs that are infested only at the ends of 

 the branches. 



Formulae for these washes are given on a later page. (See index.) 



