[ 194 j 



XXXIII. Observations on the Effects of Age upon Fruit Trees 

 of different Kinds; with cm Account of some new Varieties 

 of Nectarines. In a Letter to the Secretary. By Thomas 

 Andrew Knight, Esq. F.R.S. fyc. President.* 



My dear Sir, 

 1VTANY new varieties of fruits of different species having 

 -*-*-*- been sent from my garden to the Horticultural Society 

 in the last and in preceding seasons, and some others having 

 been seen by you in the short visit which I had the pleasure 

 to receive from you in the last autumn, I feel desirous to offer 

 a few observations upon the expediency of obtaining such 

 productions; or rather, upon the question, whether each 

 variety have its period of youth, of maturity, and of old age, 

 and be formed for a limited period of duration only; or 

 whether each be capable of eternal propagation, with undi- 

 minished health and vigour. 



The fact, that certain varieties of some species of fruits 

 which have been long cultivated, cannot now be made to grow 

 in the same soils, and under the same mode of management, 

 which was a century ago perfectly successful, is placed be- 

 yond the reach of controversy. Every experiment which 

 seemed to afford the slightest prospect of success, was tried 

 by myself and others, to propagate the old varieties of the 

 Apple and Pear, which formerly constituted the orchards of 

 Herefordshire, without a single healthy or efficient tree hav- 

 ing been obtained ; and, I believe, all attempts to propagate 

 those varieties have, during some years, wholly ceased to be 

 made. I have detailed in the Philosophical Transactions!, an 

 account of some experiments, which I repeated, with the hope 

 of being able to ascertain which, amongst the various organs 

 of trees of aged varieties, first fail to execute their proper func- 

 tions ; and I came to the conclusion, upon the following and 

 other evidence, that it is the leaf. Having obtained by layers 

 or cuttings, small plants of several of the most diseased of the 

 old varieties of the Apple, these were grafted within a couple 

 of inches of the surface of the soil with scions of new seedling 

 and luxuriant varieties; and under these circumstances the 

 roots of the most debilitated and diseased varieties executed 

 their office perfectly well, and were found, upon examination, 

 at the end of several years, wholly free from every symptom 

 of disease. This process was reversed, and scions of old va- 

 rieties were employed as grafts ; but into the young growing 



* From the Transactions of the Horticultural Society, vol. v. Part IV. 

 f For the year 1810. page 178. 



shoots, 



