590 REPORT OF STATE GEOLOGIST. 



ognize the appearance of a new form among them. Such new forms 

 come in largely along railway lines, and it is along the right of way 

 of our great trunk lines that most new species find their way into our 

 flora. Strange forms also often appear along waterways, following 

 generally the course of the current, but sometimes working against it. 

 Less frequently new forms are found entering the State along wagon 

 roads. These, the chief avenues by which weeds are introduced into 

 the State, should be carefully watched if we expect to minimize the 

 weed problem. 



The treatment of the different species of weed plants varies of 

 course with their habits. It would be impossible in this connection to 

 discuss each in detail, but a few general principles may be given, which 

 will be found applicable in a large majority of cases. Many weeds, 

 especially biennials or perennials, are exterminated most easily and 

 with the least expense by planting some early, rapidly growing crop 

 which will smother them out. A field with a good set of clover or blue 

 grass shows how effective this method is. In many cases weed-ridden 

 areas can be thoroughly reclaimed by this method with the minimum 

 of trouble and expense. 



Planting corn or root crops is a good method of dealing with weeds, 

 since the cultivation given the crops greatly reduces the spread of the 

 weeds. It can not be too clearly understood that the more thorough 

 the cultivation the fewer in number are the weeds. Professor Bailey 

 once said, "Weeds represent, in an inverse way, the energy and intelli- 

 gence of the farmer. «The greater the latter, the fewer the former: the 

 less the latter, the greater in number the former." 



Cutting and burning when in an advanced stage of growth prevents 

 production of seed, and to that extent prevents spreading. This 

 method, however, can be applied only in exceptional cases where it is 

 desired to reclaim waste areas or after the crops have been gathered, 

 as a protection against the weeds of the late summer and autumn. 



In most cases where the plant is an annual, and the majority of our 

 introduced weeds are annuals, cutting the plant before it sets seed will 

 in a few years bring about its practical extermination. The seeds of 

 but few of our weeds retain their vitality for a longer period than three 

 years, many of them not so long. 



Where the plant is a perennial, cutting the growing plant two or 

 three times a year is, perhaps, the most efficient means of getting the 

 plant under control. By this method the excess food material elab- 

 orated by the leaves and transferred to the roots for storage is ex- 

 hausted in sending out new shoots after each cutting, and none is left 

 to carry the plant through the winter and to furnish food supply for 



