- 2 - 
The list reported on includes greenhouse material showing active 
growth, plants in a semidormant condition from cold houses, and plants in a 
state of complete dormancy from out of doors. All were held for observation 
after fumigation in heated greenhouses in order to force development. 
So far as possible the plant names conform with correct botanical 
nomenclature .2/ In cases in which the correct botanical names are different 
from those familiar to the nursery trade, the latter are also listed for 
cross-reference purposes. Several of the plants listed are new varieties 
for which no approved names are available. Within some groups, notably 
azaleas, hydrangeas, rhododendrons, and roses, the varieties are listed in 
accordance with their accepted names in the trade rather than in strict 
adherence to scientific nomenclature. 
List No. 1 records those treated plants which, experimentally, have 
shown no injury or complete recovery following slight initial injury. List 
No. 2 is an account of the plants fumigated which showed injury or appearance 
of injury sufficient to render the plants more or less unmarketable. In most 
cases the numbers of plants were small. For 14 of the varieties shown no 
controls were available. In the opinion of nurserymen who cooperated in 
these tests, injury in many cases was due to improper care after treatment, 
and the plants suffered therefrom rather than from the fumigant . Pending 
additional data, all varieties contained in this list should be regarded as 
injured and handled accordingly. 
An explanation of the symbols used in the lists is as follows: 
(d) Plants in a dormant condition at fumigation, 
(sd) Plants in a semidormant condition at fumigation, 
(g) Plants from greenhouses. 
* Plant growth stimulated by fumigation. 
** Plant growth slightly retarded by fumigation. 
*** Slight injury followed by complete recovery. 
The numeral following each variety shows the number of plants fumigated. 
The lists show the effect of methyl bromide fumigation on 187 genera 
of plants representing 503 horticultural varieties and unnamed entries. Of 
these, 6.5 percent show injury or suspected injury sufficient to render the 
plants unsalable; 1.4 percent of the varieties either died or failed to make 
promising recovery. Injury was most common among growing greenhouse plants 
appearing in 12.0 percent of these varieties. Among the dormant and semi- 
dormant plants, only 3.2 percent were injured. Since many of the deaths, 
particularly among greenhouse varieties, are believed due to the kind of 
care rather than treatment, additional data may lower these percentages. 
Of the uninjured varieties, stimulation in growth, as evidenced 
primarily by early breaking of leaf or flower buds, was shown by 11.1 per- 
cent and retardation by 1.5 percent. 
2/ The writers gratefully acknowledge the assistance of Dr. S. F. 
Blake, Senior Botanist, Bureau of Plant Industry, in rsviewing the plant 
list and correcting the plant names. 
