74 MINNESOTA STATE HORTICULTURAL SOCIETY. 



ABNORMAL AND DEFECTIVE BLOSSOMS. 



As soon as this matter began to be observed the fruit growers 

 and experimenters both found that a great many plum blossoms 

 are imperfect. In the majority of such blossoms the pistil, or 

 female organ, from which the fruit itself directly develops, is 

 defective; sometimes it is entirely wanting. It is evident that a 

 blossom having no pistil cannot produce a plum, and it is at least 

 fair to suppose that any defect in the pistil renders the chance 

 of fruit-bearing much smaller. Considerable attention was given, 

 therefore, eight or ten years ago, to this part of the subject. It 

 was found that in some cases all the blossoms on a tree were so 

 deficient as to make fruitage impossible. Yet such cases were so 

 rare, and the cases of comparative deficiency so unimportant, that 

 altogether these considerations threw very little light on the gen- 

 eral orchard problem of unfruitful trees. 



While studying these plum blossoms to get a better knowledge 

 of their deficiencies, many curious abnormalities were brought to 

 light. In some plums the male organs matured before the female 

 organs (at least, such was stated to be the case, although I have 

 never observed this phenomenon). In a great many blossoms the 

 female organs matured in advance of the male organs. In some 

 cases the pistils were longer than the stamens, and in other cases 

 the stamens were longer than the pistils. Such variations had been 

 observed in other species of plants and 'had been found of the 

 highest significance in explaining the pollination of those species. 

 It was necessary, therefore, that the early investigators of the 

 native plums should have looked for some explanation of the prob- 

 lems in hand in these abnormalities. At the present time it must 

 be said that they have thus far explained nothing, and it now seems 

 probable that they throw no light on the practical questions in- 

 volved. 



SELF-STERILITY. 



Self-sterility, then, plain and simple, seems to be the main issue. 

 In the ordinary typical case the plum tree bears an abundance of 

 blossoms which are for the most part perfect, having all of the 

 organs, both male and female, normally developed, and yet being 

 incapable of fruiting by itself. The pistils simply refuse to be 

 fertilized by the pollen from the same flowers or from other flowers 

 on the same tree, or even from other flowers on other trees of 

 the same variety. 



The first practical question which naturally arose was as to 

 the extent of this self-sterility. Some varieties were thought to 



