562 FUNDAMENTALS OF FRUIT PRODUCTION 



Rough lemon stock is said to produce tall upright trees of the varieties 

 worked on it.-*^ 



Seasonal Changes. — In the orchard or vineyard, cultural practices 

 have, in the majority of cases, no very obvious influence on the time of 

 starting growth, but the effect on ripening and maturity is more marked. 

 The classical experiment of introducing a vine or a branch of a tree into 

 a warmed room during the winter, keeping its connection with the parent 

 stock and observing it start growth while the remainder of the plant is still 

 dormant, would lead to the inference that the cion is practically indepen- 

 dent of the stock in the spring flush of growth. So it proves in most cases. 



End-season Effects. Ripening of Fruit. — Concerning effects at the 

 other end of the growing season there is some conflict of evidence. It is 

 rather well known that some of the annual species of Convolvulacese 

 become perennial when grafted on perennial species." Daniel reports 

 that by grafting the annual parts of certain perennials on certain other 

 perennial plants he has succeeded in prolonging the life of the cions.*^ 

 Conversely, in some instances, cions of perennials grafted on annual 

 stocks have died at the usual time for the stocks, though Lindemuth^^ has 

 shown a case where the plant lived longer. Such instances as these are 

 more striking than those observed in fruit plants, where the possibility of 

 change is necessarily more limited. It is sometimes claimed that grafting 

 in itself hastens maturity in grapes by a few days. Cole^" states that 

 several growers in Victoria claim a few days earlier ripening in peaches 

 worked on almond than on peach stock, while in France Sahut^^" claims 

 that the Myrobolan plum induces earlier ripening in peaches than does 

 almond stock. Sahut states also that cherries ripen earlier on Laurocera- 

 sus than on ordinary cherry seedlings and the Reine Claude plum on 

 Damas is said to be somewhat earlier than on St. Julien. Cole reports 

 that heavy autumnal rains in Victoria are not so likely to induce second 

 growth or fall blossoming in plums worked on Marianna roots as in those 

 worked on Myrobolan and attributes this to the early dormancy of the 

 former stock. 



In America topworked trees were more common formerly, propor- 

 tionately at least, than they are now and discussions of mutual influences 

 were correspondingly more frequent. These discussions show a sur- 

 prising variety of experience and opinion, particularly in the effect of the 

 stock on the time of ripening of fruit in the autumn. Diametrically 

 opposite results apparently come from identical combinations of stock 

 and cion. Hovey recounted extensive combinations of early pears on 

 late and vice versa in Massachusetts, without any change from the usual 

 season of ripening. There was, however, rather good evidence that 

 plums on Myrobolan ripened earlier than on late plums. In apples, 

 Shaw states that "particularly with Rhode Island Greening the season of 

 ripening is influenced by the stock." ^^^ 



