PESTS AND DISEASES OF PLANTS 217 



Mix Part I and Part II and add enough water to make a wet mash 

 The parts should not be mixed until ready for use. Distribute broad- 

 cast in front of the pests early in the morning. 



CONTACT INSECTICIDES LIQUIDS. 

 Lime-Sulphur. 



Lime-sulphur is easily the most important insecticidal spray now 

 used, and its fungicidal properties make it even more useful to the 

 orchardist. It is especially valuable for controlling scale insects, the 

 peach twig-borer and fungi on deciduous fruit trees, though if properly 

 weakened it may also be used as a summer spray, particularly for the 

 red spiders and mites. 



Formerly lime-sulphur spray was a home-made product, but today 

 the commercially prepared product is so much more convenient than 

 the home-made mixtures and as good as the best that can be made on 

 the farm that the use of the latter has almost ceased. 



Home-Made Lime-Sulphur. 



Stone lime 50 pounds 



Sulphur, flowers of 110 pounds 



Water to make SO gallons 



Heat in a cooking barrel or vessel about one third of the total 

 quantity of water required. When the water is hot, add all of the 

 lime, and at once add all the sulphur, which should previously have 

 been made into a thick paste with water. After the lime is slaked, 

 another third of the water should be added, preferably hot, and the 

 cooking should be continued for an hour, when the final dilution may 

 be made, using either hot or cold water as is most convenient. The 

 boiling due to the slaking of lime thoroughly mixes the ingredients at 

 the start, but subsequent stirring is necessary if the wash is cooked 

 by direct heat in kettles. After the wash has been prepared it must 

 be strained through a fine sieve as it is being run into the spray tank. 

 The resultant product is a concentrated solution of lime-sulphur, which 

 should be diluted for use as directed in the table for diluting the 

 commercial lime-sulphur, which follows. 



Commercial Lime-Sulphur. 



The commercial lime-sulphur is a perfectly clear liquid needing 

 only to be diluted for use. Because of its dependency it is fast 

 replacing the home-made preparations. There are three common 

 brands upon the market in California under the trade names "Rex," 

 "Ortho'' and "Orchard," though there are many other brands which 

 may be obtained elsewhere. 



In using the lime-sulphur it is very important to have just the 

 right amount of dilution. This is ascertained by the use of a Baume 

 hydrometer. The following table shows the dilutions for dormant 

 and summer spraying with lime-sulphur mixtures: 



