COMPARATIVE STUDY OF THE ROOT SYSTEMS AND 

 LEAF AREAS OF CORN AND THE SORGHUMS 



By Edwin C. Miller,' 

 Assistant Plant Physiologist, Department of Botany, Kansas Agricultural Experiment 



Station 



INTRODUCTION 



During the summers of 191 4 and 191 5 a series of investigations was 

 conducted to determine the fundamental characteristics possessed by 

 the sorghum plants (Andropogon sorghum) which enable them to with- 

 stand severe climatic conditions better than the com plant (Zea mays). 

 The results of these investigations will be reported in a series of articles 

 as rapidly as the data are assembled. This paper deals with the com- 

 parative study of the root systems and leaf areas of corn, Blackhull kafir, 

 and Dwarf milo. These experiments were carried on at the State Branch 

 Experiment Station at Garden City, Kans. This Station is located in 

 the southwestern part of the State, in latitude 37° 58' north and longitude 

 100° 55' west (Greenwich), and has an elevation of 2,940 feet. 



EXPERIMENTAL METHODS 

 CLIMATIC DATA 



The instruments for obtaining the weather data consisted of a thermo- 

 graph, a hydrograph, a soil thermograph, maximum and minimum 

 thermometers, a psychrometer, a rain gauge, an evaporation tank, and 

 two anemometers. The maximum and minimum thermometers, thermo- 

 graph, and hydrograph were kept in a standard shelter 4 feet above the 

 ground. One of the anemometers measured the wind velocity at a height 

 of 2 feet and the other at a height of 8 feet. The 2-foot anemometer was 

 connected with a clock attachment so that the wind velocity for each hour 

 was recorded. The bulb of the soil thermograph was buried to a depth 

 of I foot. 



A portion of the weather records for the growing seasons of 191 4 and 

 1 91 5, grouped in 5-day periods, is given in Table I. This table shows 

 that the climatic conditions of 191 4 and 191 5 were in marked contrast. 

 The total rainfall for the year 1914 amounted to only 9.7 inches, while 

 that for 1 91 5 totaled 26.77 inches. 



' Acknowledgments are due Messrs. J. G. Lill and C. B. BrowTi, of the United States Department of 

 Agriculture, for their aid in obtaining the weather and soil data, and to Mr. M. C. Sewell, formerly super- 

 intendent of the Experiment Station at Garden City, Kans., for general assistance in this work. 



Journal of Agricultural Research, Vol. VI, No. 9 



Dept. of Agriculture, Washington, D. C. May 29, 1916 



dx Kans. —4 



(3") 



