FLORIDA STATE HORTICULTURAL SOCIETY 



75 



propagation or because plants are grown 

 either singly or in clonal blocks. 



With these eliminations, we may now 

 make the inquiry : When does the grow- 

 ing of a clonal varietyo/ itself reduce the 

 fruit production of which the variety is 

 capable? The answers may be stated as 

 follows, embracing three groups of con- 

 ditions : 



1. When the variety has flowers that are 

 entirely or decidedly pistillate — a grade 

 of intersexes rather frequent in many 

 kinds of plants. 



2. When adaptations prevent or limit 

 both self- and close-pollination. 



3. When self- and close-pollination do 

 not result in fertilization necessary for 

 fruit setting. 



These may be discussed briefly and in 

 the order given. 



INTERSEXES IN FRUIT CROPS 



The Dates, Figs, Persimmons, Papayas, 

 Strawberries, and Grapes illustrate well 

 the fact that among the numerous indi- 

 viduals of a species or a race there are 

 often different degrees in the relative de- 

 velopment of the two sexes in the flowers 

 which affect the ability to self-pollinate. 

 These are deviations from the perfect type 

 of flower with loss of either pistillate or 

 staminate potency, giving frequently nu- 

 merous grades of intersexes. The ability 

 to bear fruit is limited to those individuals 

 or clonal varieties that are more or less 

 potent in femaleness and in these there is 

 the possibility of self- or close-pollination 

 only when stamens or staminate flowers 

 are also developed. Otherwise there is 



need for cross-pollination. In such plants 

 the problems of fruit setting, as far as 

 pollination is concerned, are solved either 

 by hand pollination as in dates, by supply- 

 ing pollen-bearing flowers together with 

 the insects to carry the pollen as in the 

 Smyrna Fig, by proper interplanting of 

 pistillate with either male or perfect- 

 flowered plants as for certain varieties of 

 Strawberries and for Muscadine Grapes, 

 or in the development of perfect-flowered 

 and self-pollinating varieties as was done 

 in the Strawberry and is now being done 

 in the Muscadine Grapes. 



A lesson in respect to this type of steril- 

 ity may be learned from the recent ex- 

 periences with the J. H. Hale Peach. 

 Highly productive of excellent fruit in 

 nursery and orchard trials when sur- 

 rounded by other varieties, it was exten- 

 sively advertised and heralded as "the 

 million dollar Peach." When solid blocks 

 of this clonal variety came to the age of 

 yielding fruit it was found that many 

 of the fruits were undersized, poorly col- 

 ored and insipid, and that many such 

 fruits fail to mature. Examination showed 

 that the decided self-unfruitfulness of 

 this Peach is due to its poor pollen. To 

 obtain the good yields of fruit which this 

 variety is capable of bearing it is neces- 

 sary to interplant it with other varieties 

 that yield good pollen in abundance. 

 Peaches are as a rule perfect-flowered, 

 self-pollinating and highly self-fruitful. 

 This variety is hence an unexpected ex- 

 ception which arose and caused consider- 

 able financial loss to those who planted it 

 in solid blocks. 



In general it may be said that self-un- 

 fruitfulness of an intersex plant or its 



