362 



THE CANADIAN HORTICULTURIST 



need for such knowledge prompted he 

 writer to make a few simple experiments, 

 which, at least in part, go to show that a 

 few of our most common varieties may be 

 grown alone and yet a perfect set of fruit 

 secured. The observations made extend 

 over but one year, and too much must not 

 be inferred from them. In order to per- 

 fect a list of varieties which are self-fertile 

 the work should be continued for at least 

 five years, and be conducted on a somewhat 

 more elaborate scale. 



Sterility may be due to any one of several 

 causes. Some of the more common of 

 these are as follows : Defective pistils, in- 

 sufficient pollen, difference in time of ma- 

 turity between stigma and pollen, and im- 

 potency of pollen. Of these the last is per- 

 haps the only one which can apply to any 

 great extent to the apple blossom. 



In order to ascertain whether or not a 

 variety is self-fertile many different 

 methods may be followed. The plan fol- 

 lowed by the writer was very simple indeed. 

 All the material required was a number of 

 small paper bags large enough to cover the 

 cluster of blossoms, some string, and some 

 labels. One of these bags was placed over 

 the bunch of blossoms just before they 

 opened. The bag was securely tied about 

 the mouth so that no insect could push its 

 way in. Five or six such bags were placed 

 on each variety tested to provide for acci- 

 dental loss of one or more. Each bag was 

 plainly labelled with the date on which it 

 was placed on the tree, and with the num- 

 ber of blossoms in the cluster. The bags 

 were allowed to remain on the trees until 

 the fruit had set and all blossoms and many 

 weak fruits had fallen. 



On removing the bags on June 19th it 

 was found that very few varieties had set 

 fruit. It was, however, very encouraging 

 to know that a few varieties were capabk 

 of setting fruit by their own pollen. I£ 

 was found that out of tyenty-nine varieties 



tested only eight had set any fruit at all. 

 Those which set fruit were: Alexander, 

 Baldwin, Chenango, Early Harvest, Green- 

 ing, Holland, Twenty Ounce and Ontario. 

 The Baldwin had set two fruits, while the 

 others had set but one fruit each. With the 

 exception of the eight varieties mentioned. 

 ' all the other varieties set no fruit whatever 

 in the bags, while the balance of the tree, or 

 trees, set full crops of fruit in every case. 

 The non-setting of fruit in the bags may 

 have been only chance, hence it would be 

 quite unfair to say that these varieties are 

 at all times self-sterile. What happened 

 in 1902 might not occur again, and many of 

 them might prove to be self-fertile if this 

 work were continued for a number of years. 



Omitting from the list those varieties 

 which proved themselves to be capable of 

 even a very limited- self-fertilization, many 

 of our best commercial varieties are left 

 out. Blenheim, Ben Davis, Canada Red, 

 King, Mann, Fameuse, Spy, Ribston, and 

 many other more or less desirable varieties 

 seem to be unable to set fruit unless ferti- 

 lized with foreign pollen. We cannot af- 

 ford to leave all of these varieties out of our 

 commercial orchards simply because they 

 do not set fruit when planted by themselves, 

 for it is well known that in a mixed planta- 

 tion they produce paying crops. 



The question then arises : How are 

 these desirable self-sterile varieties to be 

 most profitably grown ? 



To answer the question we need to know 

 more about the dates on which the different 

 varieties bloom, because it is necessary to 

 have the pistil of one variety ripe at the 

 same time as the pollen of another, in order 

 to have complete interpollination. It will 

 be sufficient in most cases to determine the 

 date of blooming, as the pistil and pollen of 

 the apple are both ripe about the time the 

 petals open, and are capable of remaining 

 receptive for from one to fivie days. Tak- 

 ing the dates of blooming, as ascertained by 



