FUMIGATION OF CITRUS PLANTS. 

 EXPERIMENT 8. 



Condition during fumigation, dark, 62° F. 

 Condition after fumigation, shade, 67° F. 

 Dosage, 1\ ounces KCN. 

 Date, May 17, 1916, 9.50-10.40 a. m. 

 Plants in each test, 5; total, 15. 



Results. 



Condition before fumigation. 



Shade, 65° F., 

 plants dry. 



Shade, 65° F~. 

 plants wet, 



water temper- 

 ature, 68° F. 



Shade, 65° F., 



plants wet, 

 water temper- 

 ature, 100° F. 



2 



2 



2 



EXPERIMENT 9. 



Condition during fumigation, dark, 62° F. 

 Condition after fumigation, sunshine, 74° T. 

 Dosage, 1\ ounces KCN. 

 Date, March 30, 1916, 10.57-11.47 a. m. 

 Plants in each test, 5; total, 10. 



Results. 



Condition before fumigation. 



Shade, 66° F., 

 dry. 



Shade, 66° F., 

 wet. 



4 



4 



DARKNESS AND SHADE. 



In experiment 1 ten citrus plants in the dark at a temperature of 

 60° F. and ten in the shade at approximately the same temperature 

 (58° F.) were fumigated at the same time. After treatment they 

 were so divided that plants from each prefumigation condition were 

 placed under five distinct postfumigation environments, each to 

 include two plants from the darkness and two from the shade. No 

 difference in degree of injury could be detected between the plants 

 from prefumigation shade and those from prefumigation darkness in 

 any of the five postfumigation conditions. Equivalent results are 

 presented in experiment 12 between the series of plants in prefumiga- 

 tion shade and prefumigation darkness at 60° F. These results would 

 appear to indicate that neither darkness nor diffused light before 

 fumigation in any way influences the degree of injury to citrus plants 

 from treatment with hydrocyanic acid. 



