40 MAINE AGRICULTURAL KXPLRIMLNT STATION, I914. 



all over the eastern part of the United States and in Europe, 

 from whence they were brought in as weeds. 



These three plants are Sinapis avensis, which is the common 

 charlock or wild mustard. It is very abundant in Maine. The 

 Raphanus raphanistrum, or wild radish, jointed or white char- 

 lock, is also very abundant and a persistent weed. The third, 

 wild turnip, Brassica tempestris. is not so bad a weed as the 

 other two as it rarely lasts in the land more than one or two 

 years. These all belong to the mustard family and more or less 

 resemble each other in their appearance. Wild turnip has a 

 smooth leaf and stem, while both the wild radish and the wild 

 mustard are roughened with strong hairs. It is not easy to 

 distinguish between wild radish and wild mustard when the 

 plants are young. The wild radish leaves, however, are much 

 more deeply cut, the divisions between the lobes of the 

 leaves reaching nearly to the midrib. With a small magnifying 

 glass the stem hairs make it easier also to distinguish. Those 

 of the wild mustard generally protrude at right angles from the 

 stem while those of the wild radish slant downward. Wild 

 mustard has a straight, jointless seed pod which splits open 

 when dry and scatters its seed at the slightest touch. On wild 

 radish the seed pod is jointed and tends to break up in seg- 

 ments when dry. 



A somewhat superficial examination of fields indicates that 

 perhaps 75 per cent of the oat and barley acreage in Maine is 

 infested with "wild mustard", and that 50 per cent is so badly 

 infested that hand pulling cannot be resorted to with profit. 



In experiments which were conducted in Germany it was 

 found that in some instances the crop was diminished so that 

 when it was grown with the mustard there was a yield of only 

 one-third of what was grown on the same kind of land under 

 the same conditions where the mustard had been removed. 



It has been found absolutely impossible to separate wild 

 radish or mustard segments or seed from oats or barley by 

 oven the most improved types of fanning mills, or by floating 

 in water. As a result, if these weeds are permitted to mature 

 and are harvested with the grain crops, it means again seeding 

 the fields with these weeds, or else purchasing seed grain from 

 outside distributors. The cost of good seed oats free from 

 weed seeds is well known. Many farmers to be relieved of 



