238 MANUAL OF MODERN VITICULTURE. 



26 per cent. There was also a difference in the growth of 

 the grafts in favour of those callused in sand. The grafts 

 callused in straw were a disappointment, for, though when 

 planted out they seemed to have callused more successfully 

 than those in sand, they produced only 46 per cent, of 

 sufficiently good unions, and these were weaker than those 

 of the grafts callused in sand. The cause of this was pro- 

 bably the growth of moulds and wood-rot fungi around and 

 in the unions while they were in straw. 



The influence of scions of different varieties on the growth 

 of the grafts is well shown by the four varieties tested. 

 The Mondeuse, though quite satisfactory, gave a smaller 

 percentage of successful grafts than any of the others. 

 They started later than the Zinfandel, and though the 

 growth and root system were somewhat stronger the wood 

 was not quite so well matured. The Zinfandel did very 

 well, giving 64 per cent, of good grafts, and making good 

 growth. The black Ferrara, however, made almost pheno- 

 menal growth, and yielded 75 per cent, of first-class unions. 

 The growth of the Tokay was almost equal to that of the 

 Ferrara, but the number of successful grafts rather less 60 

 per cent. Fig. 179 shows an average Zinfandel graft upon 

 Rupestris St. George in comparison with an average Tokay 

 upon the same stock. It will be noticed that the larger 

 growth of top is accompanied by a corresponding develop- 

 ment of the root system. This dispels the doubt that our 

 very heavy growing varieties, especially table and shipping- 

 grapes, would succeed upon resistant vines, at least as regards- 

 Rupestris du Lot. 



The greater adaptability of Rupestris du Lot for bench- 

 grafting than of Riparia Gloire de Montpellier is well shown 

 in these experiments. Where the Rupestris du Lot gave 

 64 per cent, of first-class grafts, the Riparia Gloire de 

 Montpellier gave only 15 per cent. This is due in great 

 measure to the difference in texture in the wood of the two- 

 species. The Rupestris has thick firm wood, with short 

 joints and small pith, while the wood of the Riparia is softer, 

 more pithy, and longer jointed. In consequence of this 

 difference, it is much qasier to make a well-fitting firm 

 union with the Rupestris than with the Riparia. It would 

 appear from this experiment that grafting in the vineyard 

 when the Riparia is two or three years old would be the 

 best method for varieties of this species. 



