April, ’23] 
ARNOLD: UNIFORM FUMIGATION REQUIREMENTS 
161 
(4) Push this line toward the sea. 
The New Jersey authorities believe that such a procedure is good 
business and will stand behind such a movement to the extent of their 
power. 
Chairman E. N. Cory: We will now have a round-table discussion 
of nursery stock fumigation, led by Mr. G. F. Arnold. 
UNIFORMITY OF NURSERY STOCK FUMIGATION REQUIRE¬ 
MENTS 
By G. F. Arnold, A. & M. College , Miss. 
Abstract 
Recommendations for fumigating nursery stock in the different states vary con¬ 
siderably in the strength of hydrocyanic acid gas to use and the time of exposure 
necessary. The variations in temperature and humidity throughout the United 
States would not permit of standard fumigation regulations for the entire country. 
It would seem desirable for the states in each section (for example, the Southern 
States) to adopt similar fumigation requirements for each kind of plant to be fumi¬ 
gated. Suggest further experiments to determine the fumigation schedule that 
could be adopted in each group of states in the country. 
The subject of uniformity of fumigation requirements for nursery 
stock was discussed at a meeting of southern entomologists and nursery¬ 
men held in Atlanta last May. The object of this meeting was to agree 
on a nursery inspection system which might be considered standard for 
the Southern States. The nurserymen and entomologists present 
thought that host plants of scale insects should be fumigated as a pre¬ 
cautionary measure. 
Several of the nurserymen inquired the strength of hydrocyanic acid 
gas necessary for the different kinds of nursery stock. The entomologists 
present differed considerably in their opinions on this point. The 
majority seemed to think that one ounce of sodium cyanide to each one 
hundred cubic feet of space was sufficient for such stock as dormant 
apple, plum, pear, quince, cherry, apricot and pecan. In one of the 
states represented the regulation dosage for dormant pecan stock is 
one and one-half ounces of sodium cyanide to each one hundred cubic 
feet of space. This dosage for pecans has been used in that state in 
fumigating large quantities of pecans for several years past and no 
injurious results have been reported. 
It was brought out at the meeting that the regulations in the Southern 
States vary considerably in the dosage of cyanide prescribed for tender 
peach trees, usually termed “June-buds.” Several of the entomologists 
