A COMPARATIVE STUDY OF THE COMPOSITION OF THE 

 SUNFLOWER AND CORN PLANTS AT DIFFERENT 

 STAGES OF GROWTH 



By R. H. Shaw, Chemist, and P. A. Wright, Assistant Chemist, Dairy Division, 

 Bureau of Animal Industry, United States Department of Agriculture 



INTRODUCTION 



The sunflower plant is gaining recognition as a silage crop in certain 

 of the northwestern States where climatic or soil conditions are not 

 always favorable for the maturing of corn for silage purposes. In some 

 sections also there is a growing sentiment that sunflower silage offers a 

 more profitable feed than corn silage, because of the greater yield that 

 may be obtained per acre. 



The Dairy Division is making an investigation of sunflower silage. 

 This paper, which is the first of a series, presents the results of a study of 

 the chemical composition of the sunflower plant at several different and 

 distinct stages of its growth as compared with that of corn grown under 

 similar conditions. The purpose of the study is to assist in selecting the 

 proper stage of maturity for ensiling. 



The investigation of the corn plant was made partly as a basis on which 

 to study the sunflower plant and partly in connection with another in- 

 vestigation, the results of which will be published in a paper having to do 

 with the fermentation of corn in the silo. 



HISTORICAL REVIEW 



Numerous analyses of the sunflower plant have been published from 

 time to time. In some cases these have represented the whole plant, 

 but more often only the head or the seed. No record of any study of 

 the composition of the plant at different stages of growth has been found. 

 On the other hand, there have been several such studies, more or less 

 complete, made of the corn plant. Some of these will be briefly reviewed. 



Roberts (5) 1 selected periods of growth (1) when the plants were coming 

 into bloom, (2) when approaching roasting-ear condition, and (3) when 

 most of the ears were out of the milk . Basing his figures on the dry matter, 

 he found that the percentage of protein decreased from the first period 

 to the last, while the percentage of carbohydrates increased. 



Ladd (j) concludes that the nitrogen steadily diminishes throughout 

 the period of growth, while the sugars rise and fall. The starch falls 

 slightly during the earlier stages and then rises rapidly until the plant 

 reaches maturity. 



1 Reference is made by number (italic) to "Literature cited," p. 792-793- 



Journal of Agricultural Research, Vol. XX, No. 10 



Washington, D. C. Feb. 15, 1921 



■wv Key No. A-56 



(787) 



