MAIZE. 103 



from each such cross are to be grown in Ihe form of an ear-to- 

 row test ; each row being the product of a different cross. 

 These cross-bred rows are then studied with regard to yield 

 and the possession of other desirable qualities. 



(ii) After having found the right pair of pure strains for 

 the attainment of any desired results in the way of yield and 

 quality the method of producing seed maize for the general 

 crop is a very simple, though somewhat costly, process. 



Two isolated plots will be necessary, plots 1 and 2. 



In plot 1 will be grown year after year only that pure 

 strain which investigation has proved to be the best mother- 

 strain for the attainment of the desired end. Thus, if it has 

 been found that cross C.X.H. gives the desired result, plot 1 

 will be occupied by strain C. This will require no attention 

 from the breeder's point of view, except that any exceptionally 

 vigorous or aberrant individuals should be eliminated, as such 

 plants may be safely assumed to be the result of foreign 

 pollinations. 



In plot 2, strain C and strain H are to be planted in 

 alternate rows, and all of strain C is to be detasseled at the 

 appropriate time. All the grain gathered from the detasseled 

 rows will be seed maize for the general field crop, and that 

 gathered from the tasseled rows will be pure-bred ; strain H 

 to be used again the following yeax in the same way. Here 

 again in pure strain H all exceptionally vigorous or aben-ant 

 individuals should be discarded as being probably due to the 

 entrance of foreign pollen. 



Maize Composition. — Composition of the various parts of 

 the maize plant. Water — free basis (15). 



From the above it will be seen that the nutritive ratio 

 of the most concentrated part, the grain, is approximately 



