6 ORCHARD FRUIT TREE CULTURE 



Silver-leaf which was actually working toward the extinction of 

 the most valuable of all plums, the " Victoria," has been definitely 

 traced to the fungus Stereum purpureum, and thus far brings it 

 within control that its menace no longer alarms us. The sources 

 of other diseases have been similarly traced, and this, of itself, is to 

 be put in possession of a weapon wherewith to combat them and 

 stamp them out. " Big bud " in black currants, " American 

 mildew " in gooseberries may be noted in this category, and the 

 panicky and wasteful method of dealing with them is giving place 

 to methods altogether saner and less iconoclastic. 



" Plant breeding " is the objective of other research, and the 

 selection and standardization of fruit tree stocks is another one 

 which has unearthed much valuable data. It would be exceedingly 

 difficult to overestimate the importance of either of these, but 

 perhaps the latter makes the most direct appeal to the imagination 

 and opens up a most promising field for further research. 



A definite but quite limited knowledge as to the respective 

 merits of certain fruit tree stocks was established, on a broad 

 foundation, more than a generation ago, but research, systematic 

 because scientific, has in a few short years revealed to us how 

 really little we knew. Instead of the mere broad distinction as 

 between " free " and " dwarfing " stocks, we know now that in 

 both sections considerable and numerous varietal distinctions 

 exist, and these, being scheduled and standardized, our future 

 fruit-growers may be in the enviable position of selecting stocks 

 according to their special requirements. This is no trivial achieve- 

 ment, but is rather a movement to successful and patient investiga- 

 tion. (See illustrations 2, 3, 4.) 



Not less than four decades ago we found our speculations turned 

 in this direction, for, in a row of crabs, consisting of a dozen trees, 

 we noticed there were five distinct varieties of fruit, with correspond- 

 ing differences in habit of growth and colour of bloom. The thought 

 occurred to us to keep the varieties separate or to save the fruit 

 only of the best for seed ; but we were juniors then very much 

 junior and were not credited with perspicacity or much other 

 thought, so our suggestion fell upon deaf ears. It is, however, 

 none the less gratifying to learn that others have acted along the 

 same lines, and that at long last the idea has proved itself to have 



