INTRODUCTORY 16 



voirs where some of this food, after elaboration, is stored in such 

 receptacles as bulbs, tubers and fleshy rootstocks. The first 

 growth in spring, particularly flowering stems, is produced 

 mainly by drawing on this special store of nourishment. Plants 

 are therefore in their weakest condition when they have largely 

 exhausted their reserve supply of food and have not had time 

 to replenish it. The stage of growth, then, when plowing will 

 be most effective is when their flowering stems have made full 

 growth but before the seeds, which would be a source of danger, 

 have had time to mature. 



GENERAL PRINCIPLES. 



1. There is no weed known which can not be eradicated by 

 constant attention, if the nature of its growth be understood. 



2. Never allow weeds to ripen seeds. 



3. Cultivate frequently, particularly early in the season, 

 so as to destroy seedlings. 



4. Many weed seeds can be induced to germinate in autumn 

 by cultivating stubbles immediately after harvest. Most of 

 these seedlings will be winter-killed or can be easily disposed 

 of by plowing or cultivation in spring. 



5. All weeds bearing mature seeds should be burnt. Under 

 no circumstances should they be plowed under. 



6. All weeds can be destroyed by the use of ordinary im- 

 plements of the farm, the plow, the cultivator, the harrow, the 

 spud and the hoe. 



7. Be constantly on the alert to prevent new weeds from 

 becoming established. 



SLTtfMER FALLOWING, 



The practice of summer-fallowing land, to the exclusion of 

 all crops throughout the season, whatever may be said against it, 

 affords the best opportunity to suppress noxious weeds. For 



