907, U. S. Dept. of Agriculture 



Plate I. 



Fumigation of Citrus Plants With Hydrocyanic Acid. 



A, Fumigatorium used in experimental work, showing interior arrangement. 

 B, Orchard citrus tree fumigated in the daytime and immediately afterward 

 exposed to a hot sunshine; foliage completely destroyed. Other trees in the 

 same grove, fumigated at an equal temperature but free'from sunshine influence, 

 were uninjured. 



