Sept. I, 1920 



Line- Selection Work with Potatoes 



561 



characteristics alone yielded well above the average of the 108 lines but did 

 not equal the 33 heaviest-yielding lines of 19 18. Field notes show that 

 15 of these heavy-yielding lines of 19 18 have poor vine characteristics. 

 This means that if mass selection based on tuber characteristics is 

 practiced within these 15 lines their progeny \\i\\ be almost certain to 

 contain some rather advanced degenerate types that will materially 

 decrease the yield of the lines in 191 9. On the other hand, we can be 

 almost sure that no well-advanced or low^-yielding degenerates will 

 appear among the 19 19 progeny of those with good 1918 vine character- 

 istics. It is interesting to go back beyond the 19 18 records and compare 

 the 3-year performance of these lines assembled in Table XVI with the 

 33 highest-yielding Rural New Yorker lines when ranked upon their 

 3-year average production. The 33 lines in Table XVI have produced 

 during the 3-year period an average yield of 17,740 pounds per acre. 

 The 33 of the 108 Rural New Yorker lines ranking highest according to the 

 3-year average production by weight have yielded on an average 19,181 

 pounds. Between the two groups there is a variation of 1,441 pounds 

 in favor of the 33 lines ranked upon their performance record. But 

 when vine development so nearly foretells the yielding power of the line 

 it would really seem that this is a more practical basis for selection than 

 yields measured in either weight or number of tubers. 



Table XIII. — Three-year average numerical prodiiction of marketable tubers per hill 

 frotn 108 rural New Yorker tuber lines 



Line No. 



409. 

 410. 

 411. 

 412. 



413- 

 414. 



415- 

 416. 

 417. 

 418. 

 419. 

 420. 

 421. 

 422. 



423- 

 424. 



425- 

 426. 

 427. 

 428. 

 429. 

 430- 

 431- 

 432- 

 433- 

 434- 

 435- 



Yield. 



■ Line No. 



436. 

 437. 

 438. 

 439' 

 440. 

 441. 

 442. 



443' 

 444. 



445' 

 446, 



447 

 448 

 449 

 450 

 451 

 452 

 453 

 454 

 455 

 456 

 457 

 458 

 459 

 460 

 461 

 462 



Yield. 



3-29 

 3.02 

 3.18 

 3. 00 

 2-95 

 3- 19 

 3-48 

 2.68 

 3-04 

 3-09 

 3-32 

 3. 10 



3-07 

 2.88 



3- 04 



3. 21 

 3-38 

 3. 20 



2-93 

 2.81 

 2.78 

 2.86 

 3-04 

 3- 29 

 3. 16 

 2. 70 

 2. 90 



Line No. 



463- 

 464. 



465- 

 466. 

 467. 

 468. 

 469. 

 470. 

 471. 

 472. 

 473- 

 474- 

 475- 

 476. 



477- 

 478. 



479- 

 480. 

 481. 

 482. 

 483. 

 484. 

 485- 

 486. 

 487. 

 488. 

 489. 



Yield. 



3. 00 



3-07 

 3.02 

 2. 90 



3-04 

 2. 60 



2.77 



2-95 

 3. 16 

 3. 21 



3- 04 

 3.02 



2-95 

 2-55 

 2. 92 



2-95 

 3- 19 



2-93 

 3.02 



Line No. 



Yield. 



490. 

 491. 

 492. 

 493- 

 494- 

 495- 

 496. 



497- 

 498. 

 499. 

 500. 



501- 

 502. 



503- 

 504- 

 505- 

 506. 



507- 

 508. 



509- 

 510. 



5"- 

 512. 

 513- 

 514- 

 515- 

 516. 



2. 76 

 2.79 



3. 16 

 2.83 

 2. 69 



2-93 

 2.83 



3-25 

 2. 78 

 2.79 

 2.83 



3- 29 

 3.06 

 2. 72 



2-93 

 2. 64 

 3.60 



3-27 

 2. 74 

 2. 60 

 3-19 

 3" 

 3- 09 

 3-43 

 2-75 

 2.79 



2-45 



