50 



FUMIGATION INVESTIGATIONS IN CALIFORNIA. 



the blossoming period of 1908. Some of the results secured are 

 given in the following paragraphs. 



Experiment No. 1. — On February 28 and 29 about one-third of an 

 acre of mixed Valencia and Navel orange trees was fumigated at 

 Upland, Cal., using dosage rates of 1 ounce and Ih ounces per 100 

 cubic feet. The trees, were about 12 feet in height. At this time 

 the blossoms were just appearing on the trees, none of them being 

 far enough advanced to open. The general conditions of the blos- 

 soming may be understood by an examination of figure 14. This 



Fig. 14.— Orange blossoms at an early stage of deveiopment. (Original.) 



may be considered the tenderest stage of blossoming. An examina- 

 tion of these trees two weeks later showed that no apparent injury 

 had resulted and that the trees at this time contained as heavy a 

 set of blossoms as the surrounding unfumigated trees. 



Experiment No. 2. — On March 30 fully 1 acre of Navel and Valencia 

 orange trees about 10 feet high were fumigated at Orange, Cal., using 

 dosage rates of 1, \\, and 2 ounces per 100 cubic feet. The condition 

 of blossoming at the time of fumigation ranged from no open blos- 

 soms on some trees to full blossoms on others. An examination of 

 these trees at a later date showed that with the 1 and 1^ dosage 

 rates no apparent injury had been done. The 2-ounce rate had caused 



