WEEDS OF ARABLE LAND 87 



corn crops great care should be taken to hoe early and 

 late in spring, and pull up the Thistle by hand as long 

 as it is possible to get among the standing corn. 



The creeping roots are easily broken by the plough, 

 cultivator, or harrows, and this renders the pest almost 

 more difficult to deal with than Couch (Triticum repens) 

 or Bindweed (Convolvulus arvensis). 



The only final method of reducing the Creeping 

 Thistle consists in destroying the rootstocks, and this 

 can be done by the process of exhaustion cutting off 

 all shoots that appear until the reserve of food in the 

 roots is used up. Faithful, systematic work will in 

 this way almost certainly have the desired effect, and 

 it is this principle which is involved in the statement 

 that " the growth of a couple of root crops in succession 

 where the weed is very prevalent in arable land is a 

 sure plan of getting rid of this most troublesome agri- 

 cultural pest." 1 In root crops the hoe must be kept 

 regularly at work ; it is not enough merely to prevent 

 seeding : the new shoots must be prevented from at- 

 taining any size and strength, the end in view being to 

 encourage the roots to throw up successive batches of 

 shoots for the hoe and the sun to destroy. 



Other species of Thistles which occur in arable land 

 may be similarly attacked, but except in the case of the 

 Corn Sow Thistle (p. 101), creeping rootstocks do not 

 make the process so difficult. 



Coltsfoot (Tussilago Farfara L.), known also as Foal's- 

 foot, is undoubtedly one of the most troublesome weeds 

 of arable land, and questions are frequently asked as 

 to its eradication. It produces a dense mass of creep- 

 ing rootstocks, and is one of the few plants, like Butter- 

 bur, which send up their flower stalks before the leaves. 

 Thick flowering stalks, 4 to 1 2 inches high, and bearing 



1 Leaflet No. 166, Bd. Agric, 



