GEAIN-SOEGHUM EXPERIMENTS IN THE PANHANDLE OF TEXAS. 29 



The crop now grown commercially under the name of milo in the 

 southern half of the Great Plains area is a descendant of the old milo, 

 or "Giant milo," which was the original grain-sorghum crop of 

 Texas. It has been considerably improved by the writers through 

 selection for lower stature, earhness, and more uniformly erect heads. 

 The number of different lots and selections under experiment has 

 varied from as many as 19 in the year 1911 to only 5 during each of 

 the last three years. The different lots vary little among themselves, 

 as will be seen by comparing their average performances in Tables 

 VI and VII. The total number of plats grown in the 9-year period 

 was 107. Plats of milo and Dwarf milo are shown in figure 4. 



A study of Table VI will show that, under fairly favorable condi- 

 tions, when acre yields run from 18 to 40 bushels, as in 1908 and 1910, 



Fig. 4.— Milo (right) and Dwarf milo (left) in plats at the Amarillo Cereal Field Station, August 30, 1911. 



the average vegetative period of milo covers about 75 days. Under 

 varying seasonal conditions it has ranged from as few as 68 days, in 

 1914, to as many as 82 days, in 1916. Drought occurring very early 

 in the vegetative period results in slower growth and consequent pro- 

 longation of this period. This is seen in the seasons of 1910 and 1916. . 

 The apparent shortening of the vegetative period in 1914 was due to 

 the fact that only a few early heads appeared, further development 

 being checked by drought. 



The ripening period of milo usually covers a Httle less than 30 

 days, as in the fairly normal season of 1908. It was shortened to 

 only 23 days by the droughty conditions prevailing in 1914, the year 

 m. which only a few heads were produced. The ripening period may 

 be prolonged, however, by conditions favorable to good yields. In 

 1911, for instance, the average duration of this period was 37.5 days, 

 owing apparently to heavy rains just at the time of heading, as this 

 was followed by dry and very hot weather throughout the ripening 

 period. The average acre yield was 32.3 bushels. In 1915 the 

 extremely prolonged ripening period of 44 days is correlated with 



