2l6 



PLANT PROPAGATION 



recently, all attempts to grow European grapes in 

 America during more than 200 years resulted in failure. 

 When American vines were taken to Europe, the insect 

 practically ruined the grape industry, as it has since 

 threatened to do in California. American grape stocks 

 seem to be the only salvation. 



281. Boot-grafted vs. budded trees. For many years fruit 

 growers and nurserymen have discussed the relative advantages and 



disadvantages of whole root, 

 vs. piece root vs. budded 

 trees, largely without experi- 

 mental evidence. Arguments 

 have mostly been generalized 

 statements, only too often 

 warped by individual preju- 

 dice or pocketbook. Before 

 summarizing- the experiments 

 recently published, some lead- 

 ing opinions should be cited 

 and methods outlined so the 

 reader may choose what ap- 

 peals to him. The following 

 points must be borne in mind. 

 Nursery budding upon 

 spring-set stocks is done 

 during summer, but no 

 growth occurs till the follow- 



A, effect on resistant stock of allowing ing Season (341). The Stocks 

 cion to take root; a, resistant stock small be- Kpfnrp hpintr nlantprl in 

 cause cion has rooted at c; B, vine in which , being planted in 



cion has not been allowed to root. Note the nursery are trimmed 

 smooth union at b in each case. for obvious reasons. In 



whole-root grafting the 



cions are crown set and roots similarly trimmed. In piece-root graft- 

 ing several bits of root are used, the top piece with a crown, the other 

 pieces without any. These latter are, of course, smaller. Thus piece- 

 root grafting creates a problem of its own because of the varying 

 sizes and vigor of the pieces. Piece-root grafting may therefore be 

 said to be unfairly pitted against both budding and whole-root graft- 

 ing, which under equal conditions are equally valuable methods of 

 propagation. 



Differences of growth characteristic of each method result from 

 differences of stock trimming, not methods of propagation. Even 

 casual observation will show differences in root development 

 between budded and root-grafted trees, the latter being more hori- 

 zontal, prolonged and shallower on one side of the tree than the 



FIG. 178 GRAFTED GRAPES 



