THE MONTHLY BULLETIN. 



333 



TIME OF OPERATION. 



For red, purple and yellow scale fumigation work is usually done 

 during the winter or spring months. If black scale is present the time 

 of operation covers the period from the middle of August to the middle 

 of January, depending somewhat upon the individual locality. 



TEMPERATURE. 



To avoid the heat of the sun, fumigation is ordinarily done during the 

 night, when the atmosphere is cool. Cloudy cool days may admit of 

 some work, but all day operations are liable to cause severe burnings of 

 fruit and foliage. 



Excessive coldness is also liable to cause disastrous results. Keep a 

 thermometer on the wagon and do not operate under the following 

 conditions : when the temperature is 70 degrees Fahr. or more above 

 zero or when it is 36 degrees Fahr. or less. This latter temperature 

 should be carefully avoided especially upon damp or wet nights. 



Hot, electric winds also aid to produce severe burning and all work 

 should be suspended on nights they are blowing. 



Orchards subsequently sprayed with Bordeaux mixture should not be 

 fumigated as there results a chemical reaction which is exceedingly 

 damaging to the fruit and foliage. 



BUYING MATERIALS. 



Fumigating acid and cyanide are usually bought in large lots by the 

 fumigating contractor, the various associations, the counties and large 



Pig. 319. — Method of dosing under the estimating system, which is fast being replaced 

 by the Morrill system. (After Pierce, P. C. Jr. Ent.) 



