COTTON AND SORGHUM 179 



to a sweet stalk. The second generation of the cross segre- 

 gated as a monohybrid. Graham (1916) of India, studied the in- 

 heritance of length of glume and color of seed-coats in some 

 natural and artificial crosses. Long and short glumes behaved as 

 a simple Mendelian pair with the former dominant. In the in- 

 heritance of color of grain a series of multiple allelomorphs are 

 involved. Red may be allelomorphic to yellow or white and like- 

 wise yellow may be allelomorphic to white. The usual color 

 dominance is shown. Sometimes when yellow and white are 

 crossed the heterozygote is red and in the next generation segre- 

 gates with a 9 red : 3 yellow : 4 white ratio. Graham suggests 

 that certain of the white seeds are undeveloped reds requiring the 

 presence of yellow to cause the development of the red color. 



Some Results of Selection. Sorghum improvement by breed- 

 ing has been accomplished principally through selection. Dwarf 

 forms have occurred in most varieties and have furnished material 

 for the production of such varieties as Dwarf Milo, Dwarf Kafir, 

 etc. These varieties have been isolated through selection. Sugar 

 content has also been improved. Failyer and Willard conducted 

 selection experiments at the Kansas Station from 1884 to 1903. 

 During that time they increased the sugar content of the Orange 

 variety from 12.62 to 16. 10 per cent. At the Delaware Agricultural 

 Experiment Station even more striking results were obtained 

 (Neale, 1901). The variety Amber, from which selections were 

 made, contained on the average 11 per cent, sugar with a purity 

 of 65. One of the selections made from it had a sugar content 

 of 18.2 per cent, with a purity of 81. Dillman (1916), of the 

 United States Department of Agriculture, made several selec- 

 tions from Minnesota Amber with the object of securing an early 

 maturing, drought resistant strain. One of the selections, Dakota 

 Amber, has proved valuable. It is more dwarf in habit of growth 

 than Minnesota Amber and matures 15 days earlier. It produces 

 excellent forage as well as abundant seed. Early dwarf forms, 

 as a rule, are more drought resistant than late ones. 



Method of Breeding Sorghum. Sorghum belongs to the 

 naturally self-fertilized group of farm crops and the essential 

 features of breeding it are the same as for the group. However, 

 sorghum is more frequently cross-fertilized than most of the 

 other naturally selfed crops and for this reason it is necessary 

 to resort to bagging the panicles, where different lines are grown 

 in close proximity to one another. That bagging does not inhibit 



