CALIFORNIA CITRUS CULTURE. 



81 



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

 fruit and foliage. 



Excessive cold 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 tend to produce severe burning, and all work 

 should be suspended on nights they are blowing. 



Orchards previously sprayed with Bordeaux mixture should not be 

 fumigated, as there results a chemical reaction which is exceedingly 

 damaging to the fruit and foliage. 



VENTURA COUNTY HORTICULTURAL COMMISSIONER 



FUMIGATING SCHEDULE FOR BLACK SCALE 



SODIUM CYANIDE 



DISTANCE AROUND. IN FEET 



)TE. Quarter and half ounces are 



omitted to make 

 Cyanide 1. 



Sulphuric Acid 



e practical for field 

 I'/* Water 2. 



FIG. 55. Dosage schedule No. \ for black scale using sodium cyanide as prepared by 

 Woglum. (Essig, P. C. Jr. Ent.) 



BUYING MATERIALS. 



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

 fumigating contractor, the various associations, the counties and large 

 orchard companies who are able to get the benefits of a much reduced 

 6 cc 



