32 



THE EEPOET OF THE 



Xo. 36 



COMPOSITIOX OF TI-TE SUBSTAXCE USED IX DuSTING. 



In all my tests where both insects and diseases were to be combated, I used 

 a mixture composed of 85 per cent very finely ground sulphur and 15 per cent, 

 arsenate of lead powder, supplied ready mixed by The Niagara Brand Spray Co., 

 Burlington. The price of the mixture was $6.50 per 100 lbs. When biting insects 

 were not present, as on grapes, and on plums in the later sprayings, the arsenate 

 of lead was omitted and finely ground sulphur alone used. This reduced the cost 

 greatly as the sulphur alone cost only $2.90 per 100 lbs. Some persons used the 

 sulphur mixed with finely ground limestone. 



Outfit for Applying the Dust. 



I had the larger type of dusting outfit supplied by the Niagara Brand Spray 

 Co. They have a smaller outfit, but it cannot cover nearly so may trees. The out- 

 fit consists of a 2i/o horse-power gasoline engine, a blower and a receptacle or 



Dusting fruit trees for insects and diseases. 



hopper capable of holding about 100 lbs. of the dust. The dust is blown out upon 

 the trees through a galvanized iron pipe of about 3 inches diameter. This pipe 

 is connected wth the blast jDassage by a thick rubber tube of the same diameter. 

 The flexibility of the rubber allows the operator to direct tlie pipe in any direction 

 quickly and easily. For small trees a short pipe about 3 feet long is used, but for 

 large trees the pipe must be longer. I used one about 6 feet in length. Too long 

 a pipe is awkward as the branches interfere with it; too short will not throw the 

 dust high enough. The amount of material used can be regulated by the operator 

 by a small lever on the hopper. The outfit costs complete alxiut $265. 



KixDS OF Weathek Best Suited for Dusting. 



Dusting should not l)e done in a strong wind, because this carries the material 

 too rapidly through the air instead of allowing it to float slowly through the trees 

 and settle thickly upon the foliage and fruit. A strong wind, moreover, will often 



