Hi PROCEEDINGS OF THE EOYAL HORTICULTURAL SOCIETY. 



comparatively rapid disappearance of potato varieties from cultivation 

 is the freedom with which new ones are raised, and the taste for 

 novelties is as great among potato- growers as among any class of 

 persons. That readiness for change is based on a belief that new ones 

 may always be better than older ones. Curiosity to find what may be 

 the characteristics of new varieties is also a prominent factor in the 

 matter. Then it is again a tradition of the potato trade that varieties 

 wear out. and should often be replaced by newer ones. The trade would 

 no doubt feel hurt were it to be said that such tradition is based on 

 trading interests. In any case it does as a theory without doubt lead to 

 much business. 



Now, if we turn to some varieties of potatoes which have been long in 

 cultivation, we find that in their cases wearing out is not so evident. 

 There is the 1 Ashleaf Kidney," in cultivation from almost time im- 

 memorial, and chiefly recruited from year to year either by selecting tubers 

 for planting from their best plants, or by effecting frequent changes of 

 seed-tubers. The American 4 Beauty of Hebron ? has been here some 

 thirty years, and seems to be as useful and good cropping a var:e:y a? 

 ever. ' Magnum Bonum ' has been with us thirty years, and still it is 

 found that tubers from stocks grown in Denmark give as full crops here 

 how as the variety ever did. 'International Kidney' is still found in 

 all parts of the kingdom, giving as fine crops of tubers as ever, and it is 

 grown in the Channel Islands and in France in enormous quantities for 

 the supply of the British markets. Given varieties that newer ones have 

 failed to displace, and there seems to be no lack of endurance in them — 

 tuberous artichokes in point. 



But assuming that the theory of the deterioration of varieties is 

 correct, what may be the predisposing causes to that decay ? First, is it 

 not possible that our practice of wintering tubers for future planting in 

 dry places and exposed to air may have a weakening effect ? Does Nature 

 require that to be properly progenitive the tuber should remain in the soil 

 all the winter, but preserved from frost ? I do not advance this as an 

 absolute necessity ; I merely put it forward as a possible cause for the 

 assumed deterioration. 



Then we do as a rule — and it is noteworthy that the old ' Ashleaf 

 Kidney ' is usually an exception to the rule — plant small rather than 

 large tubers annually for crop production. In the case of other vegetables, 

 do we not select the very finest roots or plants to produce the seed for the 

 ensuing crops ? In everything we grow in gardens or fields it is the rule 

 to select for parentage the finest and the best. This is not so with the 

 potato, and if in its case we depart, as we so commonly do, from an 

 acknowledged rule, what other result can be looked for but that gradual 

 weakening or deterioration of stock must ensue? Conversing recently 

 with an old Scotch potato-grower on the cause of the fine productiveness 

 of Scotch tubers, he said that apart from Scotch soil and chmate. two 

 important factors in that strength or fertility, it was largely the practice 

 to plant large tubers, even though often cut prior to the planting. On 

 that point it may be possible to get further information. Undoubtedly 

 a common cause for real weakness in potato stocks is found in the storing 

 of tubers for planting in pits, tiers, or heaps, in which they sweat or heat, 



