Pernicious Grafting

Abstract

THE question raised in a letter on this subject from Dr. Grabham in NATURE of July 17 is one of very real interest to horticulturists in Great Britain as well as to growers in Madeira. Examples of ‘incompatibility’ between stock and scion occur in practically all the commercial fruits which are propagated by budding or grafting. Moreover, there is a very complete graded series, ranging from the case in which perfect harmony apparently exists between the two individuals, to that in which they are quite incompatible and no growth at all takes place. It may be, for example, that the dwarfing influence of certain stocks upon scions is the result of incomplete harmony. The phenomenon is more distinct in the case of stocks sometimes used for pears, upon which some varieties will grow perfectly satisfactorily for one or even two years, after which growth ceases and the plant eventually dies. A slightly different aspect of the matter may be observed in the case of plums, in which it is a matter of difficulty to induce the budded scion of some varieties to grow at all on certain stocks, and it should be emphasised that success depends upon both stock and scion. Whilst a variety which does not ‘take’ well on one stock grows quite satisfactorily on another, at the same time a stock which is unsuitable for one scion proves a good ‘mother’ to others.