210 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



During the growing period of 1914 spraying experiments were con- 

 ducted in several apple orchards to determine the fungicidal value of 

 barium-sulphur as compared with lime-sulphur solution. It was di- 

 luted at the rates of 3 pounds and 6 pounds of the crystals to each 50 

 gallons of water and was used alone, in combination with arsenate of 

 lead and in combination with arsenate of lime. Fungous diseases, 

 such as apple scab and apple leaf -spot, were controlled by this, material 

 to about the. same extent as by lime-sulphur solution, and no injury 

 to fruit or foliage was produced. 



Also, 50 peach trees were sprayed with barium-sulphur, 3 pounds to 

 50 gallons of water, about three weeks after the petals fell and again 

 one month later. Arsenate of lead (If pounds to 50 gallons) was 

 added to the solution in the first application, but not in the second. 

 No injury to fruit or foliage was produced and peach scab {Cladosporium 

 carpophilum) was thoroughly controlled. This would indicate that 

 barium-sulphur is less likely to injure vegetation than Hme-sulphur 

 solution which is known to be quite injurious to peach foliage. 



Me. J. S. Houser: I would like to ask the cost per pound of 

 barium sulphide? 



Mr. W. M. Scott: The cost so far as the manufacturers are 

 concerned has not been worked out definitely. My understanding is 

 that it will cost about four cents a pound and that at that price the 

 original cost at the factory will be a little more than lime-sulphur 

 solution but the difference will be made up by the difference in freight. 



One thing I did not call attention to and that is that with 10 pounds 

 to 50 gallons of water, it controlled the scale just as well as it did at 

 16 pounds or at 32 pounds. In other words, it would seem that when 

 combined with barium the sulphur is somewhat more effective than 

 when combined with lime, or rather, that much less sulphur is effective 

 when combined with barium than when combined with lime, which, 

 if this proves true, would make the barium product cheaper than the 

 lime-sulphur solution. 



A Member: I would like to ask if this is in the form of crystals 

 that can be reduced to dry powder? 



Mr. W. M. Scott: The formula is BaS4H20, but it can be 

 ground to a powder. 



Mr. R. L. Webster: I would like to ask in regard to destroying 

 the eggs of the oyster-shell scale, how did you determine that the eggs 

 were killed? 



Mr. W. M. Scott: I did not intend to say that it killed the eggs 

 of the oyster-shell scale. What I intended to say was that it appar- 



