HOW PLANTS GROW 



15 



increase in total weight was thereafter less rapid, reaching the maxi- 

 mum when the kernels were in the milk stage. After this the gross 

 weight decreased by over 4,000 lbs., due to drying out as the crop 

 matured. The dry matter, however, continued to increase rapidly 

 until the plants were fully ripe. Indeed, in less than a month follow- 

 ing Aug. 28 the acre of corn stored over 3,500 lbs. of dry matter! 

 When four feet high the crop was nearly 86 per ct. water and only 

 14 per et. dry matter; while when the kernels were hard and the 

 husks dry over 42 per ct. was dry matter. The mineral matter, or 

 ash, increased rapidly until the plants reached their full height. 



■ CRUDE PROTON 

 I FIBER 



:..: NITROGEN-FREE EXTRACT 

 FAT 



Fig. 6. — Nutrients in Corn Plants at Various Stages 



The shaded areas in the legend represent the amount of crude protein, fiber, 

 nitrogen-free extract, and fat in corn plants at various stages. (From In- 

 diana Station.) 



The most rapid increase in crude protein, the nitrogenous portion, 

 occurred in the period before the plants were tasseled, when cell 

 growth was most active, but some increase occurred until the plants 

 reached maturity. Altho amids — the building-stones of the proteins — 

 were constantly being formed during the development of the plants, 

 they were in turn quickly built over into the more complex, stable 

 proteins. Hence it was found in further studies that the amount of 

 amids did not increase after the plants were silked, while there was a 

 steady storage of true protein up to maturity. 



