AGRICULTURAL EXPERIMENT STATION. 193 



In the above table we have for the sake of comparison of cost 

 used two pounds London Purple to one hundred pounds of plaster, 

 and three pounds of Paris Green to one hundred pounds of plaster. 

 Experience shows that these strong mixtures are unnecessary, 

 scorch the leaves and are a waste of material. Economy would 

 suggest the use of as weak an insecticide as possible and yet secure 

 good results. 



Hammond's Slug Shot and Peroxide of Silicates contain consider- 

 able more arsenious acid than is necessary to kill the beetles. 



One pound of London Purple to one hundred pounds of plaster is 

 the strongest mixture advisable and the work can be done with less. 



The strongest mixture of Paris Green advised would be two 

 pounds to one hundred pounds of plaster, and there is good reason 

 for believing that one pound to one hundred or even two hundred 

 pounds of plaster, when thoroughly mixed and well applied, is 

 sufficient. 



The cheapest and most efficient poison for potato beetles is 

 Paris Green applied with plaster or in suspension in water. 



If plaster is not useful as a fertilizer on the land the cost could 

 be still further reduced by applying the Paris Green in water, at the 

 rate of one pound to eight^^ gallons. This method has the advan- 

 tages of less cost, greater rapidity of application, more equable 

 distribution and no danger of inhaling the poison. The Paris Green 

 is insoluble in water and has to be kept thoroughly stirred if an 

 even application is desired. This is easily accomplished with as 

 little trouble as mixing the Paris Green with plaster. An ordinary 

 sprinkler with a fine vase serves a good purpose in making the 

 application. 



SPRAYING TREES. 



Spraying fruit trees with insecticides in solution, or suspension in 

 water about the time the young fruit is forming, has become a com- 

 mon practice, and has been attended with good results. Paris Green, 

 suspended in water, one pound to eighty gallons, applied thoroughly 

 with a spraying pump with a spray nozzle, two gallons to the tree, 

 has given good results. The ravages of the coddling moth, canker- 

 worm, plum curculio and other insects are said to be materially 

 checked by this treatment at a cost of ten cents per tree. 



The station has tried " Lewis's Combination Hand Force-Pump" 

 manufactured by Lewis & Cowles, Catskill, N. Y., and find it a 



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