212 PLANT PROPAGATION 



over the union and up to the upper bud. The latter is 

 done in a variety of ways (Fig. 175). The reason for 

 doing it is that American stocks, the ones always used, 

 are less susceptible to phylloxera injury than are 

 European varieties. Care must be taken to prevent root- 

 ing of the cions, else no advantage will follow grafting. 

 Attention is called to grape-grafting experiments in the 

 paragraphs which follow. 



Contrary to general belief, Daniel declares that the character of 

 the cion graft and of the wine produced from the fruit is often 

 changed, largely because of the difference in nutrition as a result 

 of callusing the grafted parts and the consequent difficulty of sap 

 circulation. By taking advantage of such changes, Daniel believes 

 that it will be possible to produce new varieties by grafting so as 

 to combine the good qualities of French fruit with the phylloxera 

 resistance of American sorts. Grape growing by direct producers 

 (those on their own roots) is considered most desirable, so they 

 should be sought by grafting. 



Degrully, a French scientist, has pointed out that variations in 

 vines, due to grafting, should not cause apprehension. The thou- 

 sands of acres reconstructed on American stocks still thrive and 

 produce abundantly 20, 25 and 30 years after grafting. Variations 

 due to grafting, he maintains, are as yet only of scientific interest. 



272. Effects of vine grafting. Because of agitation, the Society 

 of Agriculture of France appointed a committee to investigate ef- 

 fects of grafting on yield and quality of grapes and wine. The 

 committee concluded that where the factors of adaptation and af- 

 finity of stock and cion, as well as other necessary conditions for 

 successful grape culture, have been realized, there appears to be 

 nothing to warrant the claims that grafting has a deleterious effect 

 on yield and quality of product. 



273. Experiments in grape grafting Tn California, experiments 

 in grape propagation warranted the following slightly condensed 

 conclusions (Cal. Exp. Sta. Bui. 127) : 1, A cutting graft of suit- 

 able variety makes as large and vigorous growth as a simple cutting, 

 so by bench grafting no time is lost in establishing a resistant 

 vineyard. 2, Resistant varieties difficult to root but easy to graft 

 when old should not be bench grafted. 3, Care in callusing, plant- 

 ing and treatment in nursery and especially in keeping the grafts 

 moist from the time they are made till they are in the callusing bed, 

 (Fig. 105) will enable even an inexperienced grafter to obtain at 

 least 60 per cent of good, grafted plants. 4, Callusing in sand 

 insures more perfect unions and a larger percentage of successful 

 grafts than planting directly in the nursery. 5, The moisture of 

 the callusing bed should not be excessive, and the temperature 

 should be relatively warm. 6, The growing grafts should be 



