IMPROVEMENT OF SORGHUMS BY 

 HYBRIDIZATION 



H. N. ViNALL AND A. B. CrON^ 



Bureau of Plant Industry, U. S. Department of Agriculture 



PAST work with sorghum hybrids in 

 the United States has been Hmited 

 very largely to the investigation 

 and development of natural hybrids. 

 The indifferent results attained in this 

 way gave rise to the belief that there 

 was little benefit to be derived from the 

 hybridization of sorghums. Gradually 

 the principal varieties have been puri- 

 fied and standardized by selection until 

 their improvement in this way is about 

 ended; at least the progress achieved 

 by such methods is now extremely slow. 

 Realization of this truth by those en- 

 gaged in sorghum investigations has 

 caused renewed interest in the possi- 

 bility of improvement by hybridizing 

 the best varieties. 



Artificial hybridization of sorghums 

 was begun by the Ofifice of Forage- 

 Crop Investigations of the United 

 States Department of Agriculture in 

 1914 when the writers of this article 

 made numerous crosses in the green- 

 house at Washington, D. C, and in the 

 field at Amarillo, Tex. Table I gives a 

 list of these crosses. 



Seeds from these sorghum crosses 

 were sent to several Departmental 

 field stations in the Great Plains in the 

 spring of 1914 and the first generation 

 grown that year. The second genera- 

 tion, grown in 1915, was studied care- 

 fully, but aside from being interesting 

 genetically there was nothing very 

 promising except from the crosses 

 between feterita and milo and those 

 between feterita and kafir. 



FETERITA-KAFIR HYBRIDS 



The crosses between these two varie- 

 ties were made during the summer 

 and fall of 1914 by the junior author at 



Table I : Artificial Sorghum Crosses 



* The last four crosses were made by A. B. 

 Cron at Amarillo, Tex., in the summer of 1914. 

 All the other crosses were made by the senior 

 author in the early spring of 1914 at Washing- 

 ton, D. C. 



Amarillo, Tex. Contrary to our ex- 

 pectations the Fi plants had panicles 

 with brown seeds. In shape and com- 

 pactness the panicles were practically 

 intermediate between those of Black- 

 hull kafir and feterita. In appearance 

 the plants were more like the kafir 

 parent than the feterita. They were 

 somewhat taller and the stems were a 

 little greater in diameter, but on the 

 whole the resultant plants were about 

 what one would expect except for the 

 color of the seed. The seeds of both 

 would ordinarily be described as white. 



' Mr. Cron formerly in charge of forage investigations at the Amarillo Cereal Field Station, 

 Amarillo, Tex., has been since 1918, Superintendent of Texas Substation No. 12, Chillicothe, 

 Tex. The forage crop investigations at this point are carried on cooperatively by the Bureau of 

 Plant Industry and the Texas Agricultural Experiment Station. 



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