6 Maine Agricultural Experiment Station. 1920 



As in the study of the relation of chemical composition to 

 quality so also in most of the investigations into the effect of 

 environment upon chemical composition very little significance 

 was attached to the seed as a factor influencing the composition 

 of the crop. The conclusions reached in these investigations are 

 well reflected in Le Clerc-'s statement that "soil and seed play 

 a relatively small part in influencing the composition of crops." 

 (L.c. 1910 p. 18), and that "environment rather than what has 

 been usually termed heredity is the major factor in determining 

 the physical and chemical characteristics of the wheat crop." 

 (L.c. 1914, p. 291). 



In view of the generally accepted relation between the 

 chemical composition and quality of wheat these results may 

 become of some concern to the plant breeder. However, in this 

 and similar work again the conclusions are based on the evi- 

 dence obtained from samples of commercial varieties of wheat. 

 The few experiments with pure strains of wheat entering into 

 this work were concerned with the cumulative effect of selection 

 rather than with the selection and retention of prepotent strains. 

 A common feature of most of the older publications on the in- 

 fluence of environment upon the chemical composition is that 

 they are not accompanied by baking tests, hence do not bear 

 directly on the quality of wheat. 



AVith the advent of the modern principles of plant breeding 

 a third factor, namely, the inherent characteristics of the differ- 

 ent varieties and strains, entered into the consideration of causes 

 influencing the quality of wheat. The first important question 

 confronting the plant breeder was, whether the quality of wheat 

 was merely a function of the environment indiscriminately lev- 

 elling it regardless of the individual characteristics of the differ- 

 ent varieties or strains. Biffen 9 first subjected the physical char- 

 acters associated with strength to a genetic analysis and found 

 that "strength" and "weakness" form a pair of Mendelian char- 

 acters. Upon these theoretical results a number of hard, cross- 

 bred strains have been built up and tested in the bakehouse. The 

 practical significance of the application of modern breeding 

 principles in the improvement of the quality of wheat is further 

 illustrated by the experiments of the Home Grown Committee 



9 Biffen, R. H. On the Inheritance of Strength in Wheat. Jour. 

 Agr. Sci. 1908. V. Ill pp. 86-101. 



