May 29, 1916 Root Systetus and Leaf Areas of Corn and Sorghum 329 



Blackhull kafir had increased to 5,631 sq. cm. and was 1.44 times the leaf 

 extent of the Dwarf milo. The sheath area of the corn, Blackhull kafir, 

 and Dwarf milo measured 788, 383, and 332 sq. cm., respectively. 



Stage IV. — The plants at this stage had reached an age of 10 weeks 

 and had completed their leaf development. The corn plants had from 

 14 to 15 leaves and the standard kafir from 12 to 14 leaves. The com 

 plants were 6 feet high, the standard kafir 4 feet high, while the Dwarf 

 milo had reached a height of 3 feet (PI. XLIV, fig 2). The leaf area of 

 the corn plant at maturity was 9,092 sq. cm., an area 2.3 times that of 

 the mature Dwarf milo, and 1.53 times that of the Blackhull kafir. The 

 sheath area of these 



three plants was 1,445, CO/rW /f/^F//? A^/LO 



605, and 556 sq. cm., 

 respectively, for com. 





and 



S7y=iG^ /. 



^^O 

 c/77^ 





2SO 



^TaHG£^2. 



333^ 

 Crr?2 



332 

 cm 2 



ST^G£'s3. 



SS6 



C/77S 



Blackhull kafir, 

 Dwarf milo. 



SUMMARY 



The root systems of 

 Pride of Saline com, 

 Blackhull kafir, and 

 Dwarf milo plants 

 which were grown in 

 alternate rows were 

 isolated in the field at 

 four stages of growth 

 in 1914 and at three 

 stages of growth in 

 1915. All told, the 

 root systems of 33 

 plants were isolated 

 and studied. It v/as 

 found that for a given 

 stage of growth each 

 plant possessed the same number of primary roots and that the general 

 extent of these roots in both a horizontal and vertical direction was the 

 same for all three plants. The maximum depth of root penetration for 

 mature Dwarf milo, Blackhull kafir, and corn was found to be 6 feet for 

 both the years 1914 and 1915. It was found that Blackhull kafir and 

 Dwarf milo possessed approximately twice as many secondary roots per 

 unit of primary root as did the com plant. This is true not only for 

 both years but also for all stages of the root systems examined. Both 

 primary and secondary roots of the sorghums were found to be more 

 fibrous than those of the com plant. 



ST^GE-'^, 



Fig. 3— a graphic illustration of the sheath areas of Pride of Saline 

 corn. Blackhull kafir, and Dwarf milo at four stages of the growth of 

 these plants during the season of 1914. 



