How the Plant Grows. 



11 



Concentrates are feeding stuffs of condensed nature and usually 

 highly nutritious character, such as the various grains, milling by- 

 products, etc. Indian corn, oats, bran, and oil meal are examples. 



Roughages are the coarser feeding stuffs, such as hay, corn for- 

 age, straw, silage, roots, etc. 



III. THE STUDY OF AN ACRE OF CORN. 



To illustrate and fix more clearly in mind the great basic facts 

 in plant life as briefly told in the preceding pages, there is here pre- 

 sented the classic study of Ladd of the New York (Geneva) Sta- 

 tion 1 on the development of the nutrients in a measured acre of that 

 greatest of all agricultural plants, Indian corn. 



16. Changes in a maturing corn crop. Beginning his studies July 

 30, at which time the plants were fully tasseled, and repeating the 

 examination at periods until September 23, when the crop was ma- 

 ture, Ladd secured the following data : 



Composition of an acre of Indian corn at different stages. 



The table shows that this acre of corn increased over 14,000 Ibs. 

 in weight between July 30, when tasseled, and August 21, when the 

 grains were in the milk stage. After the latter date the gross 

 weight decreased nearly 4000 Ibs. because of the water lost by the 

 maturing plants. The plants increased continuously in dry matter 

 from tasseling to full ripeness, the gain being strikingly rapid be- 

 tween the silking and glazing stages. In less than a month follow- 

 ing August 9, this acre of corn stored over 2 tons of dry matter! 

 At tasseling, on July 30, the crop was nearly 90 per ct. water and 

 only about 10 per ct. dry matter, while at ripening, September 23, 

 there were nearly 28 per ct. dry matter. The mineral matter and 

 crude protein increased rapidly at first and more slowly thereafter. 



1 Rpt. 1899. 



