BULLETIN 285 



WHEAT INVESTIGATIONS. I. PURE LINES. 1 



By Jacob Zinn. 



SUMMARY 



The present bulletin contains an account of the origin and 

 development of a number of pure lines of wheat by the method 

 of selection, including data on all the important stages, except 

 milling, from the single head selection to the bakehouse. The 

 study of the effect of the environment of Northern Maine upon 

 the physical and chemical characteristics of pure strains intro- 

 duced from Minnesota forms an incidental feature of this, 

 report. 



In 1915 several hundred wheat spikes were selected from: 

 commercial varieties representing the chief groups of hard red 

 spring wheat. Of these selections 259 heads were retained and 

 each grown in a row in the cereal crop nursery in 1916. In the 

 following year 91 strains of the original selections were grown, 

 in one two-thousandth acre plots, along with 7 pure strains 

 introduced from Minnesota. The crop from the one two- 

 thousandth acre plots furnished enough seed to make a chemi- 

 cal determination of the crude protein content of each strain. 

 In 1918 only 44 pure lines selected from Aroostook wheats and 

 6 lines of Minnesota wheats were retained and grown in plots 

 ranging from one two-hundredth to one-fortieth acre in area. 

 A complete chemical analysis of the wheat and flour of 37 lines 

 and a baking test of 31 lines were made in the spring of 1919. 



Under the same conditions of environment the pure lines 

 of wheat showed distinct differences in the physical and chemi- 

 cal characteristics and in the bread making value of their grain. 



The average weight per 1000 kernels for all lines was found, 

 to be 35.314 grams. The individual strains within a variety 

 showed a very considerable variation in the weight per IOOOj 



Tapers from the Biological Laboratory of the Maine: Agricultural 

 Experiment Station, No. 132. 



