844 



fchoots and bore comparatively many and handsome fruits in the second year 

 but died after bearing. 



Up to the present, such experiments have been repeated on all sides but 

 as yet no further desirable results have been attained than those known for 

 a long time in regard to the use of dwarf stock. In some cases it was 

 evident that the manner of grafting decided the success. Thus, for example, 

 Carriere^ reports that the varieties of pears Bon chretien Rans, Doyenne de 

 Juillet, Beurrc Gifford, Beurre Box. did not grow, or died soon after pro- 

 ducing weak shoots, if they were budded on quince {greffe en ecusson). On 

 the other hand, the results are considerably more favorable, if cleft-grafting 

 is adopted and branch tips used as scions. The fertility is unusually great. 

 Ligustrum ovalifolium as stock is also said to behave differently with differ- 

 ent varieties of lilac. Only Syringa Josikea is said to succeed when budded 

 (greffe en ecussion) while Syringa Emadi persica and others develop well 

 only when cleft grafted (greffe en fente). 



Recently special attention has been given this question in the grafting of 

 grapes because of the struggle against the grape louse. The number of 

 works on this subject is very great, so that we call attention only to a few 

 important ones. First of all Couderc- determined, by questioning about 450 

 French grape growers, that even the power of resistance of an American 

 stock to the attack of the grape louse is usually somewhat reduced by graft- 

 ing and also that the different varieties used as scions exercise an influence 

 varying in intensity. 



Cases occur, however, in which a very vigorous scion can increase the 

 power of resistance. Ravaz'', among others,' lays especial emphasis on the 

 fact that the stock influences the growth of the scion and also its fertility. 

 We owe to Hotter* precise figures on the changes in grapes, due to the influ- 

 ence of the stock. He investigated different varieties of grapes grown on 

 vines grafted on Riparia and on self roots of vines of the same varieties. 

 Among 9 varieties, yy per cent, of the juice from the grafted vines contained 

 more acid than that from the non-grafted vines, of which 65 per cent, con- 

 tained more sugar than those grafted on American stock. These statements 

 are directly opposite to those of CurteP, who found the fruit of grafted 

 vines larger, the skin thinner and the seeds less numerous but larger. The 

 juice was richer in sugar than acid, poorer in ash elements, especially phos- 

 phates, richer in nitrogenous elements but poorer in tannin. We have 

 purposely cited both observations in order to show how differently the stock 



1 Carri^re, Quelques observations a, propos de la greffe. Revue hort. 1876, II, 

 p. 208. 



2 From the Weinbau-Kong-ress of the 16th to 19th of August, 1894 in Lyon; cit. 

 Zeitschr. f. Pflanzenkrankh. 1895, p. 118. 



3 Ravaz, L., Choix des porte-greffes. Revue de viticulture 1895, Nos. 100, 

 105, 106. 



■1 Hotter, E., Der Einfluss der amerikanischen Unterlagsreben auf die Qualitat 

 des Weines; cit. Centralbl. f. Ag-rikulturchemie 1905, p. 625. 



5 Curtel, G., De I'influence de la greffe sur la composition du raisin. Compt. 

 rend. 1904. Vol. CXXXIX, p. 491. 



