HICKORIES 169 



crop of husked nuts. The wild shagbark tree growing 

 under conditions of competition with grass, bushes, 

 and other trees may not bear a nut before it is 

 twenty-five years of age, yet scions from this tree 

 when used for top-working other stocks may begin to 

 bear in two or three years from the time of grafting. 

 Some of the shagbark hybrids are more precocious 

 than either parent in bearing. Mr. Bixby is apply- 

 ing the seedling test to hickories about which there 

 is a question of parentage. He plants a number of 

 nuts from a given tree and then observes if the 

 progeny throw back to more than one species when 

 they are growing. 



In hickory grafting much experimental work re- 

 mains to be done in the choice of stocks for grafts 

 of different species. On one occasion a lot of more 

 than two hundred shagbark hickory trees grafted on 

 pecan roots for me in the south lived through their 

 first winter at Stamford but in the following spring 

 weather conditions happened to be such that one 

 morning I found the pecan stocks all burst open 

 and killed. The lesson was that northern pecan 

 stocks should have been used for grafting. In all 

 probability the southern roots had moved the sap 

 into the stocks freely at too early a date and then 

 one freezing at night sufficed to congeal the sap and 

 burst the bark away from the wood. Almost all of 

 the hickories that have been grafted upon northern 

 pecan hickory stock seem to do> pretty well upon that 

 stock, but the converse is not true. The pecan ap- 

 parently does not always do well when grafted upon 



