GEAIN-SOEGHUM EXPERIMENTS IN THE PANHANDLE OF TEXAS. 17 



THE GRAIN SORGHUMS. 



The grain sorghums consist of several very distinct groups of varie- 

 ties. Different groups and varieties react differently to environ- 

 mental conditions and therefore give different results. To understand 

 these results it is necessary to know the characters by which the 

 groups and varieties differ from each other. For this purpose a 

 glance is taken first at the relationship of the grain sorghums to 

 other sorghums. Keys to the groups of grain sorghums and brief 

 descriptions of them are inserted next, and finally keys and descrip- 

 tions covering the varieties in each group are presented. 



CLASSIFICATION.! 



The different sorghums grown in this country may be arranged 

 in a general way in four agronomic divisions, as noted below. 



(1) Grain sorghums, which include such well-known groups as kafir, durra and 

 milo, and kaoliang, and also less commonly grown groups, such as shallu, etc. 



(2) Sorgo, or forage sorghum, known also as sweet or saccharine sorghum, and 

 improperly called "cane" or "sugar cane." This group includes such well-known 

 varieties as Amber, Orange, and Sumac, as well as many others not so widely grown. 



(3) Broom com, which includes two rather distinct varieties, Standard and Dwarf. 



(4) Hay sorghums, which include Johnson, Sudan, and Tunis grasses. 



This bulletin is concerned only with the grain-producing sorghums. 

 Figure 3 shows representative kernels of the most important varie- 

 ties. The groups of the grain-sorghum section may be separated 

 by the following key: 



Spikelets broadly obovate, 4.5 to 6 mm. wide; seeds large, lenticular, 



flattened; panicle oval-ovate, short branched, compact Durra-milo. 



Spikelets oval or narrowly obovate, 2 to 4 mm. wide; seeds midsized 

 to small, ovoid, scarcely flattened. 

 Stems stout, ' somewhat juicy; intemodes short; leaves 12 to 15, 



broad, usually dark green Kapir. 



Stems slender, dry; intemodes longer; leaves 7 to 10, narrower and 

 lighter green : 

 Panicle compressed; gliunes tightly appressed to the brown or 



white seeds Kaoliang. 



Panicle conical, loose; glumes spreading, exposing yellowish 

 white seeds Shallu. 



The Dttrra-Milo Group. 



This group includes White and Brown durra, f eterita, and White 

 and Yellow milo. It is characterized by slender to midstout, dry, 

 pithy stems, 0.8 to 2 meters tall, bearing 7 to 10 rather small leaves; 

 panicles short, broad, ovate or oval, short branched, compact; 



1 Classification studies in sorghums were made by the senior writer during the period of 1903 to 1906, 

 inclusive. All obtainable domestic varieties and several hundred foreign varieties and strains were grown 

 and studied. Acknowledgment of valued cooperation in this work is made to Director W. R. Dodson, 

 of the Louisiana Experiment Station, to former Director A. M, Soule, of the Tennessee Agricultural 

 Experiment Station, and to their assistants. 



56086°— 18— Bull. 698 2 



