86 FUMIGATION METHODS 







cussion regarding daylight fumigation in California. 

 The following interesting letter from R. P. Cundiff , an 

 expert on this subject and Chairman of the Riverside 

 County Board of Horticultural Commissioners, is of 

 timely interest: "What I say upon this subject is 

 mainly from a local standpoint. While I seriously 

 doubt the practicability of daylight fumigation in any 

 locality of southern California, I am not prepared to 

 maintain that in some localities, during certain 

 climatic conditions, and for some varieties of scale, it 

 might not be done with reasonable safety. However, 

 I know of no practical fumigator who has ever advo- 

 cated it. I am under the impression that those who 

 are giving such learned opinions on this subject are 

 possessed of more of a theoretical than practical knowl- 

 edge of fumigation by hydrocyanic acid gas. 



4 ' In Riverside County we have found it necessary 

 to fumigate but little for black scale, for it has never 

 assumed the proportions of a serious pest, as in some 

 of the coast counties. Our fumigation has been almost 

 entirely for red scale. It is a well-known fact among 

 fumigators that it requires almost double the quantity 

 of cyanide to kill red scale that it does for black or 

 brown scale. This must be taken into account when 

 we come to discuss the proposition of daylight fumiga- 

 tion. Another consideration is the difference in tem- 

 perature. Riverside, being an interior county, is sub- 

 jected to several degrees more heat than localities near 

 the coast. Another point that should be considered is 

 the season of the year when the work is performed. 

 Fumigation for black scale, to be in any degree effect- 

 ive, must be done during the fall and winter months. 



