414 



T\vr:xTY-i'iGiiTii Annual Report 



its control, until freezing weather in the fall of 1916, required con- 

 siderable effort. During- 1917, however, it has been quite easily 

 kept in check and its vigor and stand were reduced until it was 

 fairly in subjection by the end of June, 1917. 



Results from various other methods of Johnson grass control 

 have been sufficiently decisive that it is not deemed advisable to 

 continue the dry fallowing experiment longer. The best economic 



Pic-. 7. — ■Wisconsin No. 6 Pedigreed Barley. Salt River Valley Farm. 



method used qji the Salt River Valley Farm has been the cultiva- 

 tion of summer tilled crops, the cost of growing being more 

 than equaled by the produce. It appears preferable to hold the 

 w^eed in check by means of disc and w^eeder until midsummer, at 

 which time some crop which can be cultivated late in the season 

 should be planted. A very effective and quick way to destroy 

 Johnson grass is close grazing by sheep. Summer fallow followed 

 bv a crop of winter grains is a fairly effective method, but a heavv 

 rain or accidental irrigation may undo a great deal of careful v.'ork. 

 Summer plowdng when the land is dry is very effective but expen- 

 sive. Continuous fallow is both slow and costly, with no returns, 

 and shoidd be supplanted by other methods. 



