THE SOEGBUM PLANT 287 



stalk has been much stunted, tillers will often grow up at 

 once and become taller than the main stalk. While 

 tillers do not usually produce a good seed crop, they are 

 satisfactory as forage. 



REPRODUCTION 



214. The sorghums are all "perfect-flowered" — the 

 pollen and ovary being in the same flower, instead of in 

 separate flowers as in corn. This is the principal botanical 

 distinction between the tribe Maydece, to which corn 

 belongs, and the tribe Andropogoneoe, to which sorghum 

 belongs. 



FERTILIZATION 



215. All sorghums are adapted to both self-fertilization 

 and wind fertilization. Apparently, self-fertilization is 

 normal in the sorghums, and is in no way injurious as it is 

 in corn (page 107) . In developing pure strains of sorghum 

 it has been found practicable to cover the heads with 

 bags before blooming, thus securing complete self-fertili- 

 zation. 



NATURAL CROSSING 



216. Under normal field conditions more or less crossing 

 takes place. Regarding this point Ball ' makes the fol- 

 lowing statement : " Just to what extent cross-fertiliza- 

 tion takes place under normal field conditions, it is, of 

 course, impossible to say. However, in the case of ad- 

 jacent rows of different varieties, flowering on approxi- 

 mately the same dates, as high as 50 per cent of the seed 

 produced on the leeward row has been found to be cross- 

 fertilized. It is probable that in a fairly uniform field 

 of any given variety a similar percentage of natural 



* Ball, Carleton R. American Breeders' Association, Vol. VI, p. 193. 



