46 



These results do not show a great difference in the rate or com- 

 pleteness of eradication accomplished by the two methods. However, 

 it must be remembered in this connection that the cost of cutting 

 the dandelions per square foot was considerably greater than for 

 spraying them. During this experiment two cases were noted where 

 spraying off had the same effect as cutting off the crown of the plant 

 in that two to four plants started up from a single root where there 

 was only one plant before. This is exceedingly common when plants 

 are cut off or partially dug out. 



THE USE OF GASOLINE AND KEROSENE ON DANDELIONS. 



Of the various substances recommended as efficient herbicides, 

 gasoline and kerosene are the most common. 



Henderson (1905) treated dandelion plants by pouring brine, gaso- 

 line, and kerosene upon cut and uncut dandelions, and concluded 

 that of the three substances used gasoline proved most efficient. The 

 other two were not wholly efficient or caused injury to the grass at 

 the point of application. 



Olive (1909) treated dandelions by applying sulfuric acid, gasoline, 

 and kerosene to the cut top of the crown. Sulfuric acid of twenty 

 per ct. strength and kerosene were found to be effective. Gasoline, 

 on the other hand, failed to kill the plants completely since the cut 

 roots sprouted in two to three weeks. 



Longyear (1918) concluded from his recent work with creosote, 

 gasoline and kerosene that these are all effective herbicides, but that 

 their use involves much time and expense, and some serious injury 

 to the lawn may result where many dandelions are present. 



In 1912, a number of large dandelion plants were selected and 

 marked with stakes. By means of an oil-can a small quantity (one- 

 half to one teaspoonful) of gasoline was squirted into the crown of 

 each plant. Seven days later eighty per ct. of the plants were dead. 

 Those which survived the treatment in time regained normal foliage. 



In 1914, gasoline and kerosene were similarly applied to marked 

 dandelion plants with the result that a high percentage of the plants 

 were killed with one application. Kerosene proved to be nearly as 

 effective as gasoline. However, the small spot of grass killed around 

 each plant was larger in the case of kerosene than with gasoline, 

 apparently because the kerosene did not evaporate as readily. A 

 patented apparatus called a " dandelion gun " with which the plants 



