Diseases and Pests of the Apple and Their Control 243 



considerable difficulties attend the manufacture of lime- 

 sulfur in small quantities. If the grower is operating a 

 large orchard, or if several smaller growers can cooperate 

 as is done in many instances, it is very often advisable for 

 them to manufacture their own solution. The materials 

 for making are : lime, use only fresh lump lime, free from 

 foreign substances and containing at least 90 per cent cal- 

 cium oxide and not over 5 per cent magnesium oxide; 

 sulfur, either flowers of sulfur or commercial sulfur finely 

 ground. Various appliances may be used for cooking lime- 

 sulfur concentrates. A large iron kettle raised from the 

 ground on loose stones, or kettles imbedded in masonry are 

 suggested. When considerable amount of spray material 

 is needed, a more elaborate plant will be practicable. 

 Cooking with steam is the most satisfactory method and 

 with a larger plant the installation of a boiler is advisable. 

 A twelve-horse boiler will furnish sufficient steam for a 

 cooker of 300 gallons capacity. Iron cooking vessels are 

 usually preferable to wooden on account of danger of leak 

 in the latter. The hydrometer is necessary for testing the 

 density of the final solution. Table XII should be fol- 

 lowed in making dilutions. 



Preparation of home-made lime-sulfur solution. 



Formula 



Fresh stone lime 50 pounds 



Commercial ground sulfur 100 pounds 



Water 50 gallons 



Place the desired quantity of lime in the cooker or 

 slaking-box, then add water (preferably hot, since hot 

 water slakes the lime more quickly). Care should be 



