44 



N. S. ENTOMOLOGICAL SOCIETY. 



Percentage of Blackspot. (Apple Scab). 



During 1916 no results as to the comparative fungicidal value of the poisons were 

 obtained on any large scale. 



On Wagner we obtained the following results from experiments conducted on a 

 very small scale, which shows some difference in the control of apple scab or blackspot 

 and of "pit" or arrested black rot. 



Unsprayed 



Lime sulphur 1.007 sp. gr. paste (acid) arsenate of 



lead 2 lbs-40 gals 



Lime Sulphur 1.007 sp. gr. powdered arsenate of lime 



f lb.-40 gals 



Barium tetrasulphide (B.T.S.) 3 lbs. to 40 gals 



Sodium sulphide (Soluble Sulphur) 1 lb-40 gals 



Paste (acid) lead arsenate 2 lbs, to 40 gals 



Powdered arsenate of lime f lb. to 40 gals 



These experiments are also on a small scale and are indicative rather than conclu- 

 sive, but considering them for what they are worth they would indicate that arsenate of 

 lime and lime sulphur may prove a much better fungicide than arsenate of lead and lime 

 sulphur. The arsenate of lime alone seems to be almost as valuable a fungicide as the ar- 

 senate of lead alone and when the arsenate of lime is added to lime sulphur it causes no 

 chemical change, while the arsenate of lead throws down 35 per cent of the sulphur in 

 solution as worse than useless lead sulphide. 



