CHAPTER XV 
SMALL FRUITS AND PLANTS 
“IOME method of destroying plant-lice, leaf-folders, 
and other insects on small plants has long 
been sought by economic workers. These 
pests can not be reached with sprays, and the 
application of certain gases seemed practical. In the 
spring of 1898 the writer began a series of experiments 
with hydrocyanic acid gas on strawberry plants to 
determine the strength that could be used with safety 
for the destruction of the root-louse, Aphis forbest. 
In these tests it was shown that strawberry plants, dug 
in the spring, could be fumigated successfully before 
being transplanted. It was found also that the plants 
could be dipped in soap and tobacco solutions with 
fair results, but the process was slow, expensive, and 
difficult. The gas remedy was cheaper, more certain, 
and easier to apply. 
Amount of gas for strawberry plants.—With the 
ordinary run of strawberry plants as they are taken 
from the nursery, two-tenths (0.2) gramme cyanide 
per cubic foot, exposed fifteen to twenty minutes, will 
be effective in killing the lice without injury to the 
plants. The roots should be as free as possible from 
dirt, and the plants should be reasonably dry. There 
is always more or less moisture on young plants, but 
under no circumstances should they be drenching wet 
at time of fumigation. Plants should not be closely 
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