CO-OPERATIVE SPRAYING. 157 



I had the pleasure, about picking time, of visiting some orchards in 

 the southeastern part of the state with Secretary Marshall. We were in 

 one orchard that had evidently been sprayed well with Bordeaux and 

 that produced something like 1,000 barrels. The quality of the fruit 

 was -excellent so far as codling moth, scab and fungus growth was con- 

 cerned. The russet due to the Bordeaux would have thrown that crop 

 from grade No. 1 to 2. 



It has been known for some time that certain mixtures of lime and 

 sulphur possessed fungicidal as well as insecticidal properties. Recent 

 demonstrations have proved that the lime-sulphur sprays have properties 

 that warrant their use when winter treatments for San Jose scale are 

 needed. Of course, we are not interested in it as a dormant spray since 

 we do not have the San Jose scale.* As a summer spray to combat 

 fungous troubles they have to be used in a more cautious manner. 

 Lime-sulphur sprays may be devided into three groups: Commercial, 

 home-made and self-boiled lime sulphur. 



Commercial lime-sulDhur, as it is put on the market by several firms, 

 is in the form ( i an orange-red solution. It is the product of these 

 two substances after having been boiled together until they go into 

 solution. The products of different firms vary in degree of concentration 

 and, as Parrot showed,! there may be a wide range of variation in this 

 respect in the product of a given firm. The only safe plan to follow in 

 using these commercial brands as summer sprays for the apple, is to 

 have a hydrometer and know just what dilution is being made, and 

 not depend entirely upon the directions upon the barrel. 



The hydrometer is a glass instrument consisting of a weighted bulb 

 with a graduated stem which determines the weight or density of liquids. 

 To test the solution suspend the hydrometer in the liquid and take the 

 reading at the surface. Hydrometers are of two kinds: Beaume and 

 Specific Gravity, which differ in the standards of measurement on which 

 they are based. These two types may be combined in the same instru- 

 ment by having separate graduations on opposite sides of the tube. 

 These instruments with a range of to 36 degrees, Beaume, or 1,000 to 

 1,330, specific gravity, are recommended for this work. They can be 

 purchased from Bausch & Lomb Optical Company, Rochester, N. Y., and 

 Eimer & Amend, New York City. A commercial lime-sulphur solution 

 testing 32 degrees Beaume will require about thirty gallons of water 

 for each gallon of concentrate as a summer spray for apples. Most of 

 the commercial brands test between 25 and 33 degrees Beaume. 



The following rule can be safely followed in diluting commercial and 

 home-boiled lime-sulphur: Get the specific gravity reading of the con- 

 centrate, ignore the figure at the left and divide by the decimal of the 

 diluted mixture, which should be 1.01. The product is the number of 

 gallons of water needed for each gallon of concentrate. This rule applies 

 to both home-boiled and commercial lime-sulphur. 



* Symons, Md. Agri. Exp. Sta. Bui. No. 131. 



t Bui. 320 New York (Geneva) Agri. Exp. Sta., 1909. 



