z»S OHIO EXPERIMENT STATION: BULLETIN 175. 



weed, mullen, curled dock and others retained their vitality after 

 being- buried in the soil for fifteen years, but that they germinated 

 slowly afterwards. The same author 1 later finds that some of the 

 seeds of pigweed, black mustard, shepherd's purse, Virginia pepper- 

 grass, May-weed, evening - primrose, smart-weed, purslane, curled 

 dock, foxtail and chickweed germinated after having been biuied for 

 twenty- five years in sandy soil. Clover seed, likewise, retains its ger- 

 minating- power for many years when buried. Continued moisture 

 and warmth or continuously favorable conditions are needful to 

 sprout these buried seeds. Just such conditions prevail in a wet 

 season. Following- rainy seasons, therefore, we may certainly ex- 

 pect weeds of several sorts to reappear. 



One needs but to take earth from shallow depths in cultivated 

 fields and place it for several weeks in a warm room or greenhouse, 

 keeping- it moist meanwhile, to learn how many buried seeds lie dor- 

 mant in the soil of such fields. These tell of what has g-one before; 

 they are silent but capable witnesses. Buried seeds explain a 

 multitude of asserted mysteries, and moreover, they must be duly 

 estimated when one undertakes to keep a clean account with a crop. 

 This stored weed seed is the account that generally shows a large 

 credit balance. 



AVOIDANCE AND DESTRUCTION OF WEEDS. 



Successful measures in destroying: weeds are founded upon a 

 knowledge of the life of the weed and of its manner of propagation. 

 To avoid introducing- or propag-ating- weeds is better than to expend 

 labor destroying- them. Some principles of weed destruction may 

 be applied universally. All are based upon a knowledge of the plant 

 to be destroyed: 



1. Strive to prevent the seeding- of all weedy plants and the 

 introduction of weed seeds. This if attained will be sufficient to 

 subdue annual and biennial weeds. It is valuable with all classes. 



2. Perennial weeds of all sorts, and especially those with 

 underground stems or extensive root systems, must be cut re- 

 peatedly to starve out these subterranean parts. With this class 

 green leaves are the feeding- org-ans and must be removed. Salt, 

 coal oil, (kerosene) or strong- sulfuric acid may be applied with or 

 without cutting- to reach the same end. Cutting- is probably the 

 cheapest of all these effective measures, unless it be salting. Man- 

 of-the-earth, Canada thistle, horse nettle, bouncing--bet and toad-flax 

 sug-gest themselves at once as examples under these suggestions. 



lBeal, W J. The Vitality of Seeds, Bot. Gaz. 42:140-143; 1905. 



