IIO WEEDS OF THE FARM AND GARDEN 



field is covered with it, it is better to summer fallow, then 

 cultivate thoroughly and hoe during the entire season, or 

 sow with oats ; plow when harvested ; disk and harrow 

 for the remainder of the season. The same method used 

 for Canada thistle may also be applied. 



Wild Timothy or Dropseed Grass. The Iowa station 

 has received many letters complaining about this weed. 

 The character of the "roots" is so different from that of 

 the roots of quack grass and the other perennial weeds 

 that we have mentioned before that it is not difficult to ex- 

 terminate. The "roots" of this weed and the allied species 

 are more or less clustered. In an experiment conducted 

 to exterminate this weed we found that by giving a shal- 

 low plowing of four or five inches, and harrowing to 

 expose the roots to the sun, they were killed, no growth 

 making its appearance during the rest of the season. Of 

 course this isi not effective during rainy weather. 



Cocklebur. The cocklebur is a serious menace to cul- 

 tivated crops in many parts of the United States, more es- 

 pecially in southern Iowa and the South. A large number 

 of queries sent out to farmers in different parts of the state 

 brought many responses. Nearly every correspondent re- 

 ported the weed. The seed habit of cocklebur differs ma- 

 terially from that of many annual weeds that belong to 

 the same family. The bur has two so-called seeds, one of 

 which has a slightly different position from the other; the 

 seed coat, too, is slightly different in structure and, accord- 

 ing to Dr. Crocker, this is the reason for delayed germina- 

 tion. Dr. Arthur, in a study of the same seeds, deter- 

 mined that the opinion generally prevailing, that one 

 seed will germinate one season and the other the 

 following, is essentially correct. We have found in our 

 own work that occasionally both seeds germinate the 

 same season. It is very plain, therefore, that if cocklebur 

 occurs in the soil you cannot hope to destroy more than 

 about one-half of the seeds in one season, and if the same 



