Sept. I, 1920 



Line-Selection Work with Potatoes 



569 



Table XXIV. — Yields in igi8 of 40 Early Six Weeks tuber lines chosen upon igi8 

 vine characteristics alone as the best of the loo lines of this variety " 



" The 26 lines starred also appear among the 40 highest-yielding when ranked on the 3-year average tuber 

 production by weight. The others have very good records for the 3-year period. Average of group, 

 20,71^ pounds per acre. 



The vine growth of the other 6 hnes is reported in the following 191 8 

 field notes: 



^^ REMARKS. 



568. A little lacking in color but fairly vigorous. 



589. A very good type with possible exception of first unit. 



533. First unit light colored and burning; other plants green and vigorous. 



596. A very good green type; first two hills lacking in vigor, but this is possibly due 



to soil. 

 585. Type fair with exception of last unit, which shows some biuning. 

 582. A light-colored, biiming type. 

 541. A good green type with exception of first unit, which is distinctly lighter and 



burning. 



In Table XXIV data are assembled to show the relation between good 

 vine characteristics and tuber production in Early Six Weeks. The 40 

 lines with best vine characteristics gave an average yield of 20,713 

 pounds per acre in 1918, while the 41 heaviest-yielding lines of 1918 

 grouped in Table XXV averaged 21,350 pounds. The 191 8 average of 

 the 100 Early Six Weeks lines was 17,344 pounds of marketable tubers 

 per acre. In this variety vine growth is almost as reliable as yield records 

 in pointing out high-yielding lines. The 3-year average yield of the 

 40 lines in Table XXIV was 19,515 pounds per acre, while the 40 lines 

 ranking highest on 3-year average tuber production by weight yielded 

 during the same period an average of 20,455 pounds. Will it pay to 

 keep yield records when 40 per cent of the heaviest-yielding lines chosen 

 with the aid of 3 years' data do not produce 1,000 pounds per acre 

 more than do 40 per cent selected in less than 2 hours upon vine charac- 

 teristics alone? 



