40 How TO MAKE GRAPE CULTURE PROFITABLE IN CALIFORNIA 



(swellings on the small rootlets) on 100 rootlets are present, the re- 

 sistance-coefficient of the vine is 16, the minimum one which is con- 

 sidered safe in France in most soils. If more are to be seen, the 

 resistance is lower, and if less, higher. If any swellings occur on 

 the larger roots (tuberosities), the resistance is below 15, and then 

 safe only in exceptional cases. The larger the nodosities and tuber- 

 osities are, the more quickly the roots will rot and the lower is the 

 resistance of the vine. 



The next step to be taken is to ascertain whether the seedlings, 

 which have shown sufficient resistance against the Phylloxera, will 

 root readily from cuttings and graft well to Viniferas. In regard to 

 the latter quality, there will not be any trouble, if the species pre- 

 viously mentioned, are used for hybridization, as they all possess 

 this. In selecting parents for hybridizing purposes in general, it is 

 necessary that the several, qualities desired in their progeny, are the. 

 aggregate qualities of the former. No hybrids will have any value in 

 California, which have not one of the four hardy species, Candicans, 

 Berlandieri, Cordifolia and Cinarea, as one of their parents. In re- 

 gard to the resistance of a new hybrid to the California vine disease 

 or its adaptation to California soil conditions, the general aspect of 

 foliage and root systems, whether it takes more after one parent or 

 the other, is indicative of its strength in this respect, but it must 

 be remembered that the greatest range of adaptation is obtained by 

 hybridizing a vine adapted to wet conditions with one adapted to 

 the very driest. Numerous hybrids will have to be rejected even 

 in this respect before something is obtained, possessing the great- 

 est usefulness. Wonderful achievements are possible in this line, if 

 properly and intelligently followed up, and it may also not be out 

 of reach, to produce vines entirely equal to the best Viniferas in 

 regard to quantity and quality of the fruit, but with a much more 

 drouth-resistant foliage. 



Press of The Pacific Tree and Vine, San Jose, Cal. 



