5 84 WEEDS : GENERAL 



or where there is any doubt about their complete destruction by 

 other mean?. 



{c) Seeds already shed by weeds may be attacked in two ways : 

 (i) They may be encouraged to grow by carefully preparing a 

 seed-bed suitable to their germination, and, when the plants 

 are up a few inches high, destroy them with the plough, grubber, 

 hoe, or harrow. This treatment gets rid of immense numbers of 

 plants, especially annuals and perennials. 



(ii) The seeds may be buried deeply with the plough, so that 

 they are unable to obtain sufficient air for their proper germination. 

 Under these circumstances many seeds soon lose their vitality, 

 and those which do germinate are either unable to produce suffi- 

 cient length of stem to reach the surface of the soil, or do so with 

 a struggle and remain in an exhausted state. 



One of the chief drawbacks to the latter practice is the fact 

 that many seeds thus buried remain in a dormant state for several 

 years, and germinate freely whenever they happen to be brought 

 to the surface by subsequent deep cultivation. Seeds of char- 

 lock, black mustard, and brome-grasses, clover-dodder, poppy, 

 and several other plants are liable to cause trouble in a future 

 crop if buried in this manner. 



{d) Besides the prevention of seeding and dispersal of seeds 

 over the land, the weeds which are already in existence and 

 which actually occupy the land must be dealt with. The follow- 

 ing methods of destruction are of general application : — 



(i) Burial. — Burial by the plough is sufficient to destroy most 

 annual weeds and seedling biennials and perennials. 



Established plants of the two latter classes, however, must 

 be attacked in a different manner, as they suffer little by being 

 covered by the soil, their stores of nutriment enabling them to 

 push forth buds which soon develop new shoots above ground. 



(ii) Cutting. — Cutting with various implements, such as the 

 plough, hoe, scythe and spud, when carried out properly, kills 

 all weeds. As indiscriminate mutilation of plants, however, is 



