136 SILAGE CROPS. 



slightly in .favor of the Southern varieties, the fact should 

 not be lost sight of that an average of G 1 ^ tons more of 

 material has annually to be handled over several times, 

 in case of these varieties of corn, in order to gain 175 

 pounds more of digestible matter per acre; we therefore, 

 conclude that the smaller, less watery, variety of corn 

 really proved the more profitable. 



At other Northern stations similar results, or results 

 more favorable to the Northern varieties, have been ob- 

 tained, showing that the modern practice of growing only 

 such corn for the silo as will mature in -the particular 

 locality of each farmer, is borne out by the results of 

 careful culture tests. 



Time of cutting corn for the silo. In order to deter- 

 mine at what stage of growth corn had better be cut when 

 intended for the silo, it is necessary to ascertain the 

 amount of food materials which the corn plant contains 

 at the different stages, and the proportion of different in- 

 gredients at each stage. From careful and exhaustive 

 studies of the changes occurring in the composition of the 

 corn plant, which have been conducted both in this coun- 

 try and abroad, we know that as corn approaches maturity 

 the nitrogenous or flesh-forming substances decrease in 

 proportion to the other components, while the non-nitro- 

 genous components, especially starch (see Glossary), in- 

 crease very markedly; this increase continues until the 

 crop is nearly mature, so long as the leaves are still 

 green. Several experiment stations have made investi- 

 gations in regard .to this point. As an illustration we 

 give below data obtained by Prof. Ladd, in an investiga- 

 tion in which fodder corn was cut and analyzed at five 

 different stages of growth, from full tasseling to maturity. 



The data given below show how rapidly the yield of 

 food materials increases with the advancing age of the, 

 corn, and also that increase during the later stages of 

 growth comes largely on the nitrogen-fed extract (starch, 

 sugar, etc.). 



