CHAPTER XV 

 SMALL FRUITS AND PLANTS 



SIOMK method of destroying plant-lice, leaf- folders, 

 I 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 for besi. 

 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, arid 

 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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