70 asn.nnoiLLiA ssaaONOO 



The results are summarized in the accompanying tables: 



Table A shows the percentage of successful unions of the various com- 

 binations, the average number of pounds per vine of the first crop, the Balling 

 per cent and total acidity of the juice and the relation between the diameter 

 of the stock and scion in June, 1915, of all vines three and four years old. 



The percentage of successful unions depends upon various factors. 

 Among the principal are: A, specific vigor of scion and stock, especially of 

 the former; B, the ease of rooting of the stock; and C, the specific capacity 

 of each variety of stock and scion to form uniting tissues. These factors 

 may be modified by the condition of the cuttings and by the health and vigor 

 of the vines from which they are made. Where the latter are defective, the 

 results may be bad through no defect of the varieties nor of the combinations. 

 A single failure must, therefore, be considered as negative and inconclusive. 

 Many failures of a stock or of a scion when grafted with different varieties 

 give strong evidence of unsuitability. Successful results are of more im- 

 portance and a single good result may be considered as proof of the suit- 

 ability of the varieties and combinations. 



These results indicate the relative ease of grafting and the vigor of the 

 nursery vines. They give no assurance of the behavior of the vine in the 

 vineyard, of their fruitfulness nor of their longevity. A vine which grows 

 well in the nursery, however, is likely to do well in the vineyard, if the 

 conditions are suitable. 



Nurserymen consider 60 per cent of first-class unions as very satisfac- 

 tory, and anything under 40 per cent as unprofitable. The average in practice 

 will be somewhere near 50 per cent. Any of the combinations in Table "A" 

 which show a percentage of not less than 60 per cent may be considered 

 worth trying and fairly sure to give good results if the soil where the vines 

 are planted is suitable to the stock chosen. 



This table gives an idea of the relative ease with which some of our 

 commonest varieties can be grafted. Valdepens, Sultana and Petite Sirah 

 gave 50 per cent or over on all stocks, with the exception of Berlandieri 

 hybrids. Some gave very high percentages on some stocks and low on others, 

 such as the Gros Mansenc with 95 per cent on Riparia gloire and only 23 

 per cent on Rip. X Rup. 3309; or the Sultanina with 85 per cent on 3309 

 and only 23 per cent on Riparia gloire. Such cases as the latter are partic- 

 ularly valuable, as the scion and stock cuttings were the same in both cases 

 and the differences can be safely ascribed to specific peculiarities of the 

 varieties. The excellence of the Valdepefias as a grafting scion is shown 

 by the high percentage of successful unions on Berlandieri hybrids, 65 per cent 

 on 41B and 60 per cent on 420A. 



Similar information is given regarding the various stocks. The high 

 percentage of successful unions with the St. George and their great vigor 

 explains the preference of nurserymen for this stock. The low percentage 

 of the Berlandieri hybrids 41B and 420A, and their relative lack of vigor do 

 not attract the nurserymen, but European experience has shown that the 

 vines become vigorous as they become older and have valuable qualities 

 of fruitfulness, longevity and adaptability to unfavorable conditions. 



