PER(n^:NTAaE score cards. 25 



General characters or special features often api)ear and are seen only 

 by general inspection. These living forms are too plastic to be brought 

 entirely under formal yardstick or cast-iron rules or methods of selec- 

 tion. The breeder must adhere to a general, clearly defined plan, but 

 at the same time he must ever be on the alert to take advantage of 

 fortuitous variations, both among his experiment breeding stocks and 

 among the plants grown for general crops. 



In the case of such plants as wheat, timothj', clover, and in fact 

 most of the field crops, which in the aggregate represent such a large 

 amount of wealth, the plant is rarely seen as an individual standing 

 out by itself where it can be compared with and chosen from among 

 its fellows. To deal with these crops they (Should be planted system- 

 aticall}' in j^lots, giving to each plant the same conditions for growth 

 as to each other j)lant, that all may be compared and the best chosen. 

 Here a scale of points such as is afforded on a score card x>i"ovides a 

 good scheme for comparing the various characteristics of each plant, 

 and for making a general summarized comparison of all the qualities 

 averaged or grouped together. 



Those facts which it may be desirable later on to collect into sum- 

 marized averages, or to express graphically for comparison, should, 

 where practicable, be recorded in numl)ers, the unit of which should 

 be kept uniform throughout the series. Thus, "in breeding wheat it 

 was found that the grades expressed by the ordinary terms of " No. 

 1 Hard," "No. 1 Northern," "No. 2 Northern," "No. 3 Northern," 

 and "Rejected," formed a confusing mass of data after a few years, 

 whether collected in connection with the various field tests or with 

 the notes of individual plants in the field-crop breeding nursery. The 

 grades are now recorded in the terms of percentage. After a series 

 of j^ears the grades of the respective mother plants of a given stock 

 can be averaged ; also the aggregate grades of the centgener broods 

 of their progeny, thus giving for a series of years the average grades 

 of one stock as compared with other stocks. 



PERCENTAGE SCORE CARDS. 



By giving a different numerical weight to the several valuable char- 

 acteristics represented in the score card, those to which the breeder's 

 attention should be mainly directed are set out in bold relief. 



In the following score card, used in comparing strains and varieties 

 of wheat in field tests, the attempt was made to place the larger values 

 on those iwints where lies the greatest source of profit to the grower: 



Baaisi for percentage score card for covipariug varieties of' tcJicat (see Jig. 1,'). 



Yield per acre - 45 



Grade of ^rain i 20 



Rust resistance - 10 



Quality of gluten 10 



Amount of ghiten • 5 



Coefficient of rise of gluten . ... - 10 



lOO 



