FIELD CROPS 381 



tors which are under the control of the farmer, but the weather con- 

 ditions vary with locality and season. In dry regions, where the im- 

 portant factor of soil moisture is unreliable, the tendency is not to 

 rely very extensively upon the tillering process, but to sow greater 

 quantities of seed per acre in order to obtain the required stand. 



Comparatively little work has been done in this country on the 

 tillering of grain, but extensive investigations of the amount of wheat, 

 oats, and barley to be sown per acre have been made, and the effect 

 of tillering may be inferred to some extent from the data obtained. 

 However, direct investigations on the subject are few as compared 

 with work on other phases of the culture of cereals. The Wyoming 

 Station has published the result of investigations on the tillering of 

 wheat, oats, and barley grown at five different places in the State, 

 namely, Laramie, Lander, Wheatland, Sundance, and Sheridan. 

 The results of this work are of interest not only in so far as they 

 concern the tillering of cereals, but also inasmuch as they throw 

 light on the growing of grains at high altitudes and in arid climates. 

 The altitude of the different places where these experiments were 

 made varied from 4,000 to 7,200 feet. In one case only were the 

 plants grown without irrigation. The tillering experiments were 

 conducted with a comparatively small number of plants, but in order 

 to show what the results might be in actual field practice, a series 

 of plat experiments with different amounts of seed per acre was made 

 for the purpose of comparison. 



In general, the results indicate that the number of mature heads 

 produced by each seed varies greatly with the locality and the sea- 

 son, and that the number of heads and the amount of grain pro- 

 duced increase rapidly with the space given each seed. It was found 

 that plants grown at wide distances apart produced shorter straw and 

 a greater proportion of straw to grain than when thickly planted. 

 The greater proportion of straw is considered to be due to the increase 

 in the number of adventitious stems and the number and size of the 

 leaves as each plant is accorded greater space within certain limits. 

 It was noticed that, where too much room was given, many more 

 stems were produced than would mature heads ; and that, on account 

 of the continuous growth from the crown of the stool during the sum- 

 mer, the grain matured late, did not fill well, and consequently was 

 light in weight and of inferior quality. Larger heads were produced 

 upon grain planted more than 1 inch apart, although they did not 

 seem as uniform in size as the heads of plants grown at the smaller 

 distance. The number of seeds in the largest heads produced was 

 found to increase rapidly with the distance between plants. It is 

 stated that more grain will be produced by each seed when planted 

 at greater distances than 1 inch apart, but that the actual amount 

 of grain will be less for the area of land used. "A study of our ex- 

 periment seems to indicate that in farm practice sowing seeds so 

 plants will be secured about 1 inch apart in the drill will produce the 

 largest yields per acre of wheat or barley, but that oats should prob- 

 ably be planted a little thicker than this." 



The author concludes from his investigations that, if 80 per cent 



