Sept. I, 1920 



Line-Selection Work with Potatoes 



555 



Table VI. — Twenty highest- yielding of 108 Green Motmiain tuber lines when ranked on 

 3-year average numerical production of marketable tubers per hillO' 



Line No. 



*332 

 *404 



*376 

 *333 



*373 



Yield. 



Line No. 



396 



*354 



*320 



406 

 *343 



Yield. 



3.93 



3-93 

 3-88 

 3.86 

 3-84 



Line No. 



*362 

 394 



*324 



310 



*3o6 



Yield. 



3.84 

 3.81 



3-75 

 3-75 

 3-74 



"The IS starred lines also appear among the 20 highest-yielding when ranked on the 3-year average 

 production of marketable tubers by weight. Ten of these lines, printed in bold-face type, appear 

 among the 19 lines selected in 1918 as having uniformly good vine characteristics. Average of group, 

 4.40 tubers per hill. 



Table VII.- — Twenty lowest-yielding of loS Green Mountain tuber lines when ranked on 

 j-year average numerical production of marketable tubers per hill o- 



a The 12 lines starred also appear among the 20 ranking lowest in weight of marketable tubers. None of 

 these 20 low-yielding lines have good vine characteristics. Average of group, 2.40 tubers per hill. 



The 19 lines selected in 191 8 as having uniformly good vine charac- 

 teristics have been grouped in Table VIII. The 191 8 average of these 19 

 lines is 26,260 pounds. In Table IX appear an equal number of the 

 heaviest-yielding lines of 191 8, with an average production for the year 

 of 29,267 pounds. The 108 Green ^Mountain lines gave an average yield 

 of 17,493 pounds in 191 8. It will be noted that selection based upon 

 vine characteristics alone came very near isolating the high-yielding lines 

 for that season. The 19 lines appearing in Table VIII have as a group 

 a 3-year average record of 23,270 pounds of marketable tubers per acre. 

 The 19 lines standing highest when ranked on their 3-year average yield 

 of marketable tubers have as a group an average of 25,131 pounds. The 

 variation between the two groups, 1,861 pounds per acre, hardly seems 

 sufficient to repay the labor involved in keeping yield records. 



Table VIII. — Yields of ig Green Mountain lines chosen upon vine characteristics alone 

 as the best of the 108 lines of this variety in igi8 ^ 



•^ The lines starred appear among the 20 highest-yielding lines when ranked on the 3-year average production 

 by weight of marketable tubers. Average of group, 26,260 pounds per acre. 



