No. 6. DEPARTMENT OF AGRICULTURE. 697 



sprouts. These beloug to certain varieties, or else were produced 

 from vines that never matured. These tubers have sufficient nourish- 

 ment for the one or two sprouts sent above ground, and make de- 

 sirable seed. But most "seconds" used in planting push several 

 buds, whether planted whole or cut into halves. They have more 

 sprouts than they can feed vigorously. More than this, the number 

 of plants in the hill is too great for the fertility of the soil. The soil 

 of garden strength and tilth may take care of this excessive number 

 of plants per acre, and push growth so that a fair proportion of the 

 numerous setts will attain a good size. Some nearly maximum 

 yields have been obtained in this wa}'. But success was due not to 

 the seed but the soil that was equal to the emergency. For the or- 

 dinary soil and season, the number of plants per acre should be 

 limited by the use of seed pieces having a smaller number of eyes 

 than do "seconds," whole or in halves. 



FoiiB of Seed. — The form of the tuber is- modified by the soil and 

 season. A crop of ill-shapen potatoes may be gotten from choice 

 seed because the ground was hard and interfered with symmetrical 

 development, or because the season caused growth to be checked and 

 then to be resumed after a portion of the tuber had begun to mature. 

 It follows that results from selection for form are not as satisfactory 

 as those gotten from similar selection in the corn field. 



But one should select a variety whose type is pleasing, and then 

 select seed fairly true to type. This is entirely practical for a 

 grower on a small scale, but in commercial growing there are ob- 

 stacles. The season or soil may have affected form temporarily, or 

 the potatoes brought from a northern point for growing may be 

 too costly to permit culling for conformity to type. I find it profit- 

 able always to select for vigor, and there selection must end with 

 many growers. By selection for vigor is meant the discarding of 

 all tubers whose appearance does not warrant faith in their ability 

 to make strong plants. The drawn appearance of the bud at the 

 so-called stem or butt end of the tuber, the presence of weak buds 

 just starting, or of little potatoes in the bud, the tendency in a round 

 or semi-round variety to form a point at the tip end with undue num- 

 ber of eyes, a hard, brittle texture that causes the cutting-knife to 

 W'Ork with difiQculty, dark streaksi or blotches undter the skin — any 

 one of these characteristics should condemn a tuber for planting. 

 When a man f)lants one hundred acres or only one acre, it is impos- 

 sible that he can afford not to exercise the care necessary to secure 

 a stand of strong plants. Some large growers assume that such 

 care is out of the question. They are planting extensively in rich 

 soil and get good yields. While such is the case, they are not getting 

 the yields they should secure so long as some hills are failures be- 

 cause they would not discard a worthless piece of seed and supply 

 a vigorous piece. Every piece of worthless seed represents a failure 

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