186 Bulletin 228. 



any tendency to degeneration inherent in the propagation lay means 

 of tubers. The cost of the frequent introduction of new varieties or 

 sending to northern locahties for fresh seed, is such that much of the 

 area devoted to potatoes in New York is annually planted with 

 tubers more or less reduced in vigor. If a system of seed selection 

 that is practicable for the farmer to follow and would prevent the 

 deterioration of the desirable vigorous sorts, so as to hold them up 

 to their highest point of excellence, or, perhaps, even lead to their 

 further improvement, were understood and practiced, it would in- 

 crease the average yield per acre without materially increasing the 

 cost. 



Let us first consider the practice of farmers in seed selection and 

 point out some of the causes that lead to deterioration of varieties. 

 The tuber does not belong to the root system of the plant, but to the 

 stem. It is not a true seed: that is in the seed ball. At a certain 

 stage in its growth the plant throws out a branch or stem that, in- 

 stead of rising above ground, and producing leaves, flowers and seeds, 

 remains under the surface and at its extremity produces a cluster of 

 buds (eyes) which are surrounded by and imbedded in a mass of 

 succulent growth — chiefly starch, w^hich constitutes the tuber. The 

 nutrient material contained in the tuber is intended for the nourish- 

 ment of the buds when they start to grow. The tubers tend to par- 

 take of the nature and characteristics of the plants that produce 

 them. If the plant was a strong and vigorous one, having a tendency 

 to produce a goodly number of large \\ell-formed tubers, each of those 

 tubers will partake of the characteristics of the parent and under 

 favorable conditions will produce similar strong plants. If the 

 plant is a weak one, having a habit of setting few tubers and growing 

 these only to small or medium size, these tubers will also inherit and 

 transmit the characteristics of the parent plant. A tuber from a 

 vigorous plant producing a large hill of potatoes, though itself small 

 because it was started late and did not have time to develop full size, 

 would possess and transmit the characteristics of its worthy parent. 

 So, also, the fair sized tuber from a weak hill in which it alone at- 

 tained merchantable size, would inherit the tendencies of its parent. 

 We see, then, that inspection of the individual tuber alone will not 

 enable us to judge whether it inherits great vigor or not. To judge 

 this we must know the character of the hill it came from, or back of 

 this the vigor of the plant that produced the hill. The whole plant, 

 then, must be studied as an individual — not the single tuber. 



While the variety is new or when the stock has recently come from 

 a locality where vigor is well maintained, nearly all the plants pro- 



