48 WEEDS OF FARM LAND 



be pulled out easily should be constantly spudded in order 

 to exhaust the underground parts as much as possible. Corn 

 sowthistle (Sonchus arvensis) is one of the weeds that require 

 constant attention. It should be cut early in the year soon 

 after it comes above ground, and the cutting should be 

 repeated as often as possible during the season. 



After the weeds have been collected they should on no 

 account be allowed to lie about on the ground, particularly if 

 they are approaching the flowering stage. Such plants as 

 docks and thistles have such large stores of food in their 

 underground parts that if they are far enough advanced 

 it is in many cases possible for them to continue growing 

 even after they are pulled up from the soil, so that they 

 can ripen and shed their seed. For this reason the ac- 

 cumulation of docks and thistles in heaps in the hedgerows 

 should be discountenanced. All weeds and parts of weeds 

 should be burned straightway or removed from the field and 

 mixed with lime to rot them down into a compost. Even 

 this latter proceeding is dangerous if seeding is at all advanced, 

 as many seeds have such a hard covering that they fail to 

 rot, and even though they are buried in the lime they are 

 likely to remain uninjured in the compost heap ready to 

 spring into activity when the manure is spread on the land and 

 favourable conditions arise for germination. 



When a heap of manure is kept for any length of time and 

 reaches a fairly high temperature in the interior it is probable 

 that many weed seeds perish from the heat developed. Some 

 species seem proof against almost any adverse circumstances, 

 and very frequently the first plant to spring up where a heap 

 of stable manure has stood is knotgrass (Polygonum aviculare\ 

 while fat hen (Chenopodium album} grows so freely upon a 

 manure heap that it is often called mixen-weed or muck-weed. 



As it is all-important to prevent seeding any practicable 

 method should be adopted to avoid it. In some cases wild 

 radish is troublesome and is too abundant to be pulled out by 

 hand. It has been suggested x that when it occurs among corn 

 crops the plants should be " topped" with a scythe at the time 

 of flowering so that seed formation is impossible. 



It is sometimes advisable to reverse the order of working 

 and to begin to effect a clearance before ploughing is done. 

 This is specially useful after dirty crops like peas, which leave 

 a stubble full of such pests as couch-grass and twitch. A 



^Jour. Ed, Agric. (1908), XIV, p. 696. 



