22 BULLETIN 162, U. S. DEPARTMENT OF AGRICULTURE. 



good unions were made by the inarch-graft method. These are now 

 growing in the experimental orchard. Both the American and the 

 Japanese sorts seem to be growing fairly well on this stock, but the 

 danger feared is that Diospyros virginiana and D. Jcaki will both out- 

 grow the root of D. texana, or at least that the trees will be dwarfed 

 and checked in growth for this reason. Diospyros texana is distrib- 

 uted over a wide stretch of semiarid country in southwestern Texas, 

 where soils are shallow and very calcareous. The tree has never been 

 known to die from root-rot. Its drought resistance is exceptional, 

 but it apparently responds to a more generous supply of moisture. 



A recent importation of a wild persimmon from China, Diospyros 

 lotus (S. P. I. 17905 to 17907), by the Office of Foreign Seed and 

 Plant Introduction, is extremely promising as a stock. (See figs. 5 

 and 6.) Five trees set out in the spring of 1907 have made an excel- 

 lent growth and are quite resistant to the soil difficulties. The 

 behavior of the trees thus far indicates that this species is entirely at 

 home here. It may prove to be as good a stock as the native per- 

 simmon because it seems to be quite as resistant to the soil difficulties, 

 and it may prove to be even better because of its more rapid growth. 



Pyrus betulaefolia (S. P. I. 21982), a wild pear from China which has 

 been previously referred to, gives indication of being a good stock 

 for pears in this section. The appearance and growth of the trees 

 here indicate that the species is more resistant to those soil difficul- 

 ties that noticeably affect the pear on its own roots. 



Grape. — At this time there are no table grapes of special value 

 that can be grown here on their own roots. The crown grafting of 

 the native mustang grape (Vitis candicans) has been successful, 

 although on the uplands this grape does not do as well as some of the 

 cultivated varieties. There may be other native grapes or hybrids 

 between them and the cultivated varieties that will do well for stocks, 

 but of the many tested at this station none has appeared so promising 

 as the variety known as Lukfata. Eight vines of this variety have 

 been under trial for six years, and none of them has shown suscep- 

 tibility to either root-rot or chlorosis, the two most serious diseases 

 affecting the grape. There is good reason to believe that by the utili- 

 zation of these resistant stocks the list of grapes adapted to this sec- 

 tion may be materially increased, thus giving an entirely new out- 

 look for grape production. 



Walnut. — The Persian walnut is not grown in this part of Texas 

 at this time. Repeated trials have been made, which resulted only 

 in failures. This was due undoubtedly to the fact that the walnut 

 was worked on a stock that was not able to survive these soil con- 

 ditions. Both native species of the walnut, Juglans nigra and J. 

 rupestris, are proving to be adaptable stocks for the Persian walnut. 

 Experiments in the propagation of the Persian walnut on these 



