Sept. 1, 1920 Line-Selection Work with Potatoes 553 



If with these records before us we attempt to point out apparently 

 promising hnes, we must base our judgment either upon the frequency 

 with which tiie line appears among the high-yielding lines or upon its 

 performance as indicated by the 3-year average. The following 191 8 

 field notes are upon the lines that have appeared at least two out of the 

 three seasons among the 20 highest or that rank with the 20 highest 

 according to the 3 -year average. 



LINE 

 NO. REMARKS. 



332. First two units lacking in vigor but others vigorous. Variations may be due 



to soil. 



388. Fourth unit a typical semi-ciu-lydwarf . 



354. First unit semi-curlydwarf. 



391. A good vigorous type. 



2,^2i- A good vigorous type. 



390. A good vigorous type. 



363. A good vigorous type; third unit inclined to semi-curlydwarf. 



306. First unit curlydwarf ; others fairly vigoroxis. 



372. A good vigorous type. 



324. A fairly good type; a few weak plants, but these may possibly be due to soil. 



373. Variable as to vigor; some plants with curlydwarf tendencies, though all are 



fairly vigorous. 

 343. A good vigorous type with exception of first unit. 

 362. A good vigorous type. 

 404. A good vigorous type. 

 317. A good vigorous type. 

 338. A good vigorous type. 

 383. A very good type; some variation as to vigor, but this may possibly be due to 



soil. 

 320. Vigorous with exception of third unit, which is a typical semi-curlydwarf. 

 330. A good vigorous type. 



348. Units I, 4, and 5, very vigorous; other two very good type. 

 310. First unit with curlydwarf tendencies; others very vigorous. 



Of these 22 lines, only 9 were noted as having uniformly good vine 

 characteristics in 1918. Eight contained four or more hills with degen- 

 erate tendencies, and 5 showed variations in vigor which possibly might 

 have been attributed to soil but which may, on the other hand, turn out 

 to be the first signs of degeneration. Yield records do not promise to be 

 very effective in dealing with degeneration. It is true that those lines 

 which have appeared frequently among the lowest-yielding are typical 

 degenerates, but degenerate tendencies are also noticeable among the 

 high-yielding ones. On the other hand, 7 of the 19 lines noted with good 

 vine characteristics in 191 8 have each appeared once among the low- 

 yielding 20 in Table IV. This indicates that low yields are not always 

 associated with degeneration. 



The number of tubers produced in the hill is often suggested as a point 

 worth considering in making seed-potato selections. In Table V will be 

 found a summary of numerical tuber production in the 108 Green Moun- 

 tain tuber lines. There is a maximum variation in the 3-year averages 

 of 3.45 tubers per single-stemmed hill. The 20 ranking highest in 



