Agricultural Journal (Cape of Good Hope) 13(11): 713-715 ( Nov 24, 1898)

The Effect of the Graft on the Flavour of the Fruit

Respecting the influence exerted by the graft on fruit flavour, the experiments of M. Daniel have proved that when the black Belgian haricot, which possesses a pod of an agreeable taste, is grafted on a Soissons haricot, which has a very disagreeable flavour, the bean which is produced on the grafted plant acquires the objectionable quality of the fruit of the plant which has been used as the stock. In the same manner, he has practically demonstrated that if the Savoy cabbage be grafted on the turnip, it acquires the peculiar flavour of the latter plant. However, to quote the Gardeners' Chronicle:—

"The most interesting work, as regards the importance of its results, which has ever been undertaken in horticulture in connection with the graft, is undoubtedly that which relates to the reconstitution of vineyards destroyed by the phylloxera. Certain American Vines whose roots resist the attacks of the insect are employed as stocks, whereon are grafted native Vines, which, thus protected, continue to yield fruit 'after their kind.' Now, it is an important and admitted fact that, apart from certain other results to which allusion need not now be made, the graft of European on American Vines does not alter the quality of the wine. The soils which gave noted wines under the old régime, says M. Ravaz, the Director of the Viticultural Station at Cognac, yield the same product with Vines grafted on imported stock, and nothing is changed from this point of view. Similarly, in his work on The Principal Varieties of Vines, M. Cazeaux states that whilst grafting on American stocks may deepen the colour of the grapes, and of the red-wine produced therefrom, whilst the maturity of the fruit may thereby be improved and hastened, the operation of the graft does not affect the taste, or the perfume, or the bouquet of the produce; and other authorities might be quoted to the same purpose.

It does not, however, follow that the operation of the graft has no effect whatever on the taste of the fruit, merely because the quality of the wine which is produced retains its old-established reputation, inasmuch as recent experiments with other plants tend to show that one of the effects of the graft, when suitably applied, is indeed to ameliorate the savour of the fruit.

It must, moreover, be remembered that the theory of the graft has been completely altered during the present decade. The orthodox opinion on the subject implied that hereditary variation was purely of sexual origin, and, in a text-book which was published less than seven years ago, one of the most distinguished European botanists stated that the graft is a valuable means of fixing and conserving all the variations introduced into the embryo, because the process itself does not produce the slightest variation.

A very important communication on this subject was read at the recent horticultural congress in Paris, and afterwards at the Académie des Sciences. The author, M. Daniel, gives a résumé of all the experiments which he has made relating to the reciprocal influence of the scion on the stock, and vice versa, including the effect on the taste and quality of the fruit.

It is not possible to give more than the following abstract of the results, which have, moreover, been published in detail in the Mémoires of the National Horticultural Society of France:—

1. The reciprocal influence of the scion and of the stock cannot be denied, even though it may not always act with the same intensity.
2. This influence may bear on the general nutrition of the plants, and indirectly on its size, vigour and resitance to parasites; or it may affect the internal and external morphological character of the plant, including its organs o reproduction, e.g., the fruit.
3. Those variations are frequently of an hereditary character, and appear during the course of the second generation.
4. This effect of the graft offers several practical advantages, viz., the production of larger and 'better' fruit and vegetables (such as an improvement in their taste); and the direct production of new varieties, e.g., a modification of the colour of flowers, of the shape of fruit, &c.
5. The effect is more marked in herbaceous than in ligneous plants, and on the progeny of the grafted plant than on the plant itself.
6. The graft, which produces variation in the seed, may be employed to produce new varieties. The variation may frequently be diverted culturally, so as to impart, almost assuredly, after repeated graftings, certain qualities (taste, shape, colour, &c.) to a plant' which did not originally possess them, and which varies easily under cultivation. As regards other plants, the graft still affords the means of obtaining variation, however difficult it may be; and as soon as the change is observed, it can 1w pursued in the desired direction, and with good results."