126 



Pollination of Fruits. 



[May, 



matured on plants that were hand-pollinated, than on the plants, 

 the pollen of which was only transferred by the draft due to the 

 ventilation of the house. 



Raspberries and loganberries, enclosed in bags during 

 blossoming but not hand-pollinated, did not mature as well as 

 bushes in the open. 



Gooseberries, black, red, and white currants matured hardly 

 any fruit, but where they were hand-pollinated all matured fruit 

 plentifully. 



The following table gives a summary of the general results 

 of the writer's trials with fruit tree blossoms made between 1911 

 and 1920 : (1) Excluding insects ; (2) Hand pollinating with 

 pollen of its own variety by means of brush or forceps; (3) 

 Hand pollinating with pollen of other varieties. 







1 



2 



3 





Insects excluded. 



Self-Pollinated. 



Cross- Pollinated . 





© 



No. of 

 bags 

 used. 



No. of 

 fruits 

 set. 



No. of 

 fruits 

 matured 



No. of 1 

 bags 

 used. 



No. of' 

 fruits 

 set. 



No. of 

 fruits 

 matured 



No. of 

 hags 

 used. 



No. of 

 fruits 

 set. 



No. of 

 Iruits 

 matured 



Apple 



Pear 



Plum 



Cherry 



Peach 



108 

 38 

 27 

 18 

 I 



540 

 115 

 71 

 62 

 1 



330 

 163 

 170 



53 

 1 



36 

 27 

 7 5 

 16 

 { ) 



252 

 73 

 51 

 51' 

 2 



288 

 56 

 250 



J 1 



71 



18 

 93 

 62 

 2 



323 

 97 

 98 

 93 



o 



640 

 165 

 269 

 323 

 8 



231 

 63 

 147 

 199 

 6 







789 



717 



154 



130 





246 



616 



1.405 



646 



On an average five flower buds were enclosed in each bag, 

 but a slightly larger number in the case of cherries. The 

 camel hair brush used for pollinating was sterilised after use 

 by dipping in methylated spirit. There were several handicaps 

 to the experiments, some of which were : — (1) Bisk of destruc- 

 tion by insect attack (aphis, psylla. caterpillars hatching out 

 in bag) ; (2) Eisk of destruction by fungus attack (Brown rot 

 disease) ; and (3) Bisk of missing the most favourable time for 

 pollination. Although a larger number of trials in each kind of 

 fruit would have given more accurate information, the results 

 obtained give some data regarding fruit pollination. For 

 instance, in the case of apples, twice as many fruits matured 

 when a variety was pollinated with its own pollen as when left 

 with insects excluded, while three times as many matured with 

 cross-pollination as when flowers were pollinated with their own 

 pollen. 



Judging from the opinion of investigators in America, and 

 from the writer's own observations extending over several years 



