DIPPING AND FUMIGATION OF NURSERY STOCK 7 



As the San Jose scale is a sucking insect, it is impossible to destroy 

 it by using a poisonous spray, so a contact spray must be used. The spray 

 must be strong enough to either destroy the scale outright, that is, con- 

 sume its body, or have great penetrating power, like the oil emulsions which 

 burn and smother the insects. 



According to Lodeman, lime-sulphur spray was first used for the Con- 

 trol of insects in 1851, by a Frenchman by the name of Grison, a gardner at 

 Versailles, France. Grison used the following formula at first but later 

 reduced the amount of lime to half. 



Flowers of sulphur 500 gms. 



Freshly slaked lime 500 gms. 



Water ' 3 liters. 



Boil for ten minutes, draw off the clear liquid and use 1 to 100 parts 

 of water. This mixture was used as a fungicide and is one of the few early 

 spray preparations still in use. 



Regarding the first use of lime-sulphur washes in America, Lodeman 

 says: "A mixture similar to the following was originally used in California 

 as a sheep dip, but as fruit trees began to drive out the sheep, the applica- 

 tions of the compound were transferred to the trees, and thus it has been 

 very generally used, and has proved to be of value in the orchards as well 

 as on the sheep. It is used against insects and fungi. 



Lime (unslaked) 25-40 pounds 



Salt 15 pounds 



Sulphur 20 pounds 



Water 60 gallons 



"To mix the above, take 10 pounds of lime, 20 pounds of sulphur and 

 20 gallons of water. Boil until the sulphur is thoroly dissolved. Take the 

 remainder, 15 pounds of salt and 15 pounds of lime, slake and add enough 

 water to make the whole 60 gallons. Strain and spray on the trees when 

 milk warm or somewhat warmer. This can be applied when the foliage is 

 off the tree and will have no injurious effect upon the fruit buds or upon the 

 tree itself." 



Marlatt says "the early experience with lime-sulphur and salt washes 

 for San Jose scale was unfavorable, largely due apparently to the fact that 

 the observations on the trees treated were not continued long enough to 

 note the effect of the late summer results. Good results were obtained with 

 the kerosene emulsions and particularly with the soap washes and the fish- 

 oil soap washes." 



The formula which is commonly used at the present time in making 

 home made concentrated lime-sulphur solution is as follows: 



Lump Lime 40 pounds 



Sulphur 80 pounds 



Water . 50 gallons 



About 10 gallons of hot water is added to the sulphur and thoroly 

 stirred. The lime is then added. As the lime slakes hot water is added as 

 necessary to, prevent caking. When the lime has completely slaked 

 enough hot water is added to make 50 gallons and the solution boiled for 

 an hour and kept constantly stirred. Water is added from time to time to 

 keep the liquid up to 50 gallons. This concentrated solution should test 

 about 31 degrees Beaume. It should be stored in tight barrels until ready 



