586 FUNDAMENTALS OF FRUIT PRODUCTION 



ADAPTATION OF STOCKS TO PARTICULAR CONDITIONS 



Further, it must be remembered that a plant that is valuable to the 

 grower in one location may prove otherwise in another. Climatic condi- 

 tions may simplify the choice for a certain grower by eliminating all 

 but the most hardy stocks, but they may complicate matters for the 

 nurseryman who is selling to a wide territory. 



Adaptation to Soil Temperatures. — A grower ordering stock from a 

 nursery in a milder climate should consider that he may be getting trees 

 with stocks not adapted to his conditions. A northern grower, for exam- 

 ple, securing plum trees from the south, would do well to make sure that 

 they are not on peach or Marianna roots, though some of the leading 

 nurseries no longer use these stocks. The southern grower may be more 

 interested in securing a stock that will not sucker or in extreme cases, as 

 cited by the Howards,^" he may even require a stock that is able to endure 

 high soil temperature. These investigators found that in Baluchistan 

 the peach and plum stocks commonly used in Great Britian would not 

 succeed, but by using stocks which they considered better adapted to hot, 

 dry soils, such as Marianna, Myrobolan and Mahaleb, they secured much 

 better results. 



Adaptation to Soil Texture and Composition.^ — Prune trees in the Paci- 

 fic northwest have been planted in many cases without much regard to the 

 stock on which they were worked. In numerous instances prunes with 

 peach roots have been planted in rather heavy, poorly drained land in 

 which the planting of peach trees would not be considered. 



French horticulturists had not solved the problem presented by phyl- 

 loxera when they had isolated certain varieties of American grapes that 

 were resistant to this pest, that lent themselves to making good cuttings 

 and satisfactory graft unions with the Vinifera cions. Many of the 

 French vineyard soils are strongly calcareous; in these soils only compara- 

 tively few of the American vines flourish. Hence, ability to withstand 

 calcareous soils must be considered in any choice of stocks for rather wide 

 use in France. When California vineyards were invaded by phylloxera 

 the stocks tried and approved in France were naturally given early 

 consideration. However, lime tolerance is not so important in California 

 since comparatively little vineyard soil is calcareous; of much greater 

 importance, in some localities in this state, is ability to withstand di'ought, 

 in others ability to flourish in soils with a high water table for part of the 

 year. Rupestris St. George (du Lot), because of its deep roots, with- 

 stands drought better but suffers severely when the water table stands 

 near the surface for long; the shallow rooted Riparia Gloire and certain 

 Berlandieri hybrids meet requirements here. Most Vinifera-American 

 hybrids adapt themselves to these conditions. The Muscadine grapes 

 also are adapted to moist soils and hot climates."^ In California, as in 



