64 Maine Agricultural Experiment Station. 1920. 



as given in table I are all for clusters which did or did not de- 

 velop fruit. If it is desired to determine the fruit which set 

 per flower the results should be multiplied by this number to 

 obtain the number of fruit buds worked. 



The selfmgs which matured apples are the only ones which 

 are recorded as successful. Many of those which fall in the 

 unsuccessful group did start to develop and some even remained 

 after the June drop for a short time. These are not recorded, 

 however, since this paper deals with this problem chiefly from 

 the viewpoint of the mature, marketable fruit. 



TABLE 1. 

 Fertility of the Ovule to Pollen Within the Same Variety. 



METHOD OF POLLEN APPLICATION. 



















Pollinated 



with the 





Flower 



clus 



ter 



bagged 



Pollinated 



with pol- 



riollen of 



a different 







and 



left 





len of s 



ame 



tree 



tree but same 

 ety 



van- 



Variety 

























Fruit 



No 



Fruit 



Fruit 



No 



Fruit 



Fruit 



.\o 



Fruit 





matured 







matured 







matured 







Baldwin 



2 







11 



3 





22 







2 



Ben Davis 









65 







229 







26 



Crab 









3 







8 









Duchess 











1* 





3 









Early Harvest 









6 







7 









Golden Russett 









15 







46 







6 



Hurlbert Sweet 









5 







10 









Mcintosh Red 









16 







12 









Northern Spv 









1 







34 



1* 





3 



Red Astraehan 















4 









Rhode Island 









2 







10 







2 



Greening 























Wealthy 



1 





















*These apples were very poor specimens from which no seeds germinated. The 

 seeds themselves were shrunken and shriveled. 



From this table it is clear that most varieties of apples show 

 more or less pronounced self sterility. Within the twelve varie- 

 ties under consideration only four showed any fertility to their 

 own pollen. For those which showed such fertility the Wealthy 

 was self fertile once, the Duchess was doubtfully self fertile in 

 one out of four trees; the Baldwin was self fertile in five out 

 of forty crosses and the Northern Spy was doubtfully self fer- 

 tile in one out of thirty-nine trials. It is clear from these results 

 that the proportion of the flowers which are self fertile to their 



