24 



Fig. S. 

 Wild Oat. 



Avena fatua (L). 



An annual weed with erect and smooth stems. The leaves and 

 stems are covered with white bloom, which give a peculiar white-green 

 color to the whole plant. The head forms a loose panicle, with nod- 

 ding and spreading branchlets. I^he awn is long and bent, and 

 covered with brown hairs. It is bent most when dry ; but if 

 moistened, it uncoils and wriggles around, thus causing the seed to 

 move appreciable distances. 



The principal points of differences between the wild and culti- 

 vated oats are (1) In the former the chaff' is thick and hairy, while in 

 the latter it is thin and hairless ; and (2) The wild oat has a long, 

 stiff awn which is bent and twisted when dry, while the cultivated 

 oat either has a much smaller and less stiff" awn or none at all. An 

 average plant produces about 800 seeds. 



Time of flowering, July. Time of seeding, July- August. 



Dispersal— conveyed from place to place by threshing machines, 

 and as an impurity in seed-grain. 



Wild oats are at home in any soil that will grow cereals, and 

 they ripen their seeds among almost any cereal crop. The seeds pos- 

 sess wonderful vitality, some of them remaining buried in the soil for 

 years and germinating as soon as they are brought under favourable 

 conditions. 



Eradication. On a field infested with wild oats, cereal crops 

 should be dropped out of the rotation as far as possible ; and hoed crops, 

 soiling crops, hay, and pasture should take their place. To get the 

 land under grass, it should be fallowed during part of the season, the 

 cultivation being frequent and shallow, to destroy all seeds that may 

 have germinated in the upper layer of the soil. The land can then be 

 sown with winter wheat and seeded, or with an early variety of 

 barley, which should be cut on the green side. The treatment men- 

 tioned IS suitable for pasture land, or land which has produced a haj 

 or soiling crop during the forepart of the season. 



