EXPERIMENT STATION BULLETINS. 2G9 



a i>ouiul of good lawn seed can be sold for five cents or even ten cents. 

 The analyses given above will ex]»lain bow it can be done. 



Tables I, II, IV, V and VI and the discussions of them reveal the 

 fact that weed seeds are abundantly present in ^le seed sold in Mich- 

 igan. The importance of this can not be over-emphasized. It is prob- 

 ably not going beyond the actual fact to assert that at least ninety 

 per cent of the weeds that api)ear on a farm have been introduced as 

 contaminations of the seed sown. This agency for the introduction 

 of weeds is being demonstrated on a large scale right now in Mich- 

 igan. Alfalfa is a new crop for most farms in Michigan and prac- 

 tically all the seed so\vn these past two years (the jjeriod the writer 

 has had the matter under observation) has come from the West, Mon- 

 tana, Nebraska, Kansas and Utah, mainly. As will be noticed by 

 reference to Table V 20 to 40 per cent of all the samples examined 

 in 1911 and 1912 by the Department of Botany contained seed of 

 Russian thistle. This weed is a native of Southeastern Russia and 

 was introduced twenty or thirty years ago into the West where it is 

 now widespread and a frequent pest of the alfalfa fields as well as 

 elsewhere. During the latter part of summer and early fall in both 

 1911 and 1912 the writer has received a great many plants of Russian 

 thistle that have appeared in farms in all parts of the state, as new 

 weeds, and the significant fact is that with one excei)tion, they have 

 appeared as weeds in alfalfa fields. The connection is obvious. Sim- 

 ilarly Eruca sativa, Roquette, has appeared as a weed in a great many 

 alfalfa fields the past two seasons. This is well established as a weed 

 (introduced from Euro])e) in many of the alfalfa regions of the West. 

 A glance at the tables of seeds will not reveal this in more than two 

 samples. The fact was that, until the specimens of the weed began 

 to be sent for identification, the seed which had appeared frequently 

 in the samples of alfalfa seed examined had been wrongly identified 

 (thus Alyssum alyssoidcs and Conringia orientolis of the list were 

 probably in all cases Eruca sativa) or had failed to be identified and 

 were placed in the reports among miscellaneous seeds. Having found 

 the weed so abundantly in alfalfa fields, we now are able to recog- 

 nize its seed in many of the samples previously sent in. 



The great prevalence of buckhorn, field sorrel, etc., in fields of red 

 clover and alsike or timoth}^ respectively, corresponds clearly to the 

 abundance of the seeds of these weeds in clover and alsike or timothy 

 seed. 



Greatly to be deplored is the too common practice of cutting for hay 

 the part of a clover or timothy field where the stand is fairly pure 

 and cutting for seed the portion of the field where the stand is thin 

 and too weedy to make good hay. It seems absurd that a thinking man 

 could do such a thing but apparently the faith of such a man in the 

 power of a fanning mill to remove weed seeds is immense. It is re- 

 gretted that it is not the general instead of the exceptional practice of 

 the general farmer to save for seed that portion of the field that is the 

 cleanest. Indeed, common-sense would dictate that a field to be cut for 

 seed should be gone over carefully and all the weeds present pulled 

 or cut. This extra care is well repaid in the freedom of the seed from 

 contamination. Equally blind is the practice of those men who go to 

 a seed dealer and buy his screenings or poor grade seed because it is 



