rWENTIETII AXNUAL MEETING. 67 



Bordeaux mixture for the control of apple scab. Taking 

 the average of all recorded experiments comparing the 

 effectiveness of lime-snlphur as against Rordeanx, show 

 that the lime-sulphnr has, if anything, been more efficient 

 in reducing the seal), in our experiments in 1909, while 

 unsprayed trees sho^v•e I 43 per cent scabby, trees spraved 

 with lime-sulphur showed only 3.6 per cent, as against 3 

 per cent on trees sprayed with Bordeaux. This past season 

 the same variety (Greenings) showed 79.4 per cent scabby 

 on unsprayed trees, wdiile lime-sulphur sprayed showed 

 only 10.9 per cent, against 17.7 per cent scabby on Bordeaux 

 sprayed. 



The fungicidal value of lime-sulphur is increased by at 

 least 50 to 100 per cent by the addition of arsenate of lead 

 (2 pounds to 50 gallons) to the dilute solution. This Mr. 

 Wallace has proven beyond question, both by laboratory 

 tests and on the trees. This fact alone is worth the cost of 

 the investigation many times over. This means that a 

 w^eaker dilution of limc-suli)hur can l^e used with equal 

 effectiveness and hence with less expense. On this basis 

 w^e shall this next season use a dilution of 1-40 (32 degrees 

 Baunie test) instead of 1-30. Not only is the fugicidal 

 value of the combination greater than that of the lime-sul- 

 phur alone, but the insccticidal value is by no means de- 

 creased. Then to this may be added the fact, that the 

 burning qualifies of the lime-sulphiw are actually reduced 

 by the addition of arsenate of lead. Taken all together, 

 the facts show that from nearly every point of view the ad- 

 dition of arsenate of lead to lime-sulphur is desirable. 

 Moreover, it is so far as ice knozu at present, the only insec- 

 ticide that may i<nth safety and efficiency he used in the 

 linie-sulpJiur. Arsenate of lime, arsenate of soda, and Paris 

 green, all tend to increase tlie burning and are unsafe with 

 lime-sulphur. 



Another very interesting discovery of Mr. Wallace's, 

 is that ma<^}iesiuni oxide, one of the chief constituents of 

 impurities in lime, has considerable fuiit/icidal value. r>oth 



