THE HORTICULTURAL SOCIETY OF NEW YORK 



A lesson in respect to this type of sterility may he learned from 

 the recent experiences with the J. H. Hale Peach. Highly pro- 

 ductive of excellent fruit in nursery and orchard trials when sur- 

 rounded by other varieties, it was extensively advertised and her- 

 alded 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 colored 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 necessary 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 exception which arose and caused 

 considerable financial loss to those who planted it in solid blocks. 



In general it may be said that self-unfruitfulness of an intersex 

 plant or its clonal variety arises because its flowers are imperfect 

 and do not supply viable pollen suitable for any sort of fertili- 

 zation. 



In certain cases, as for some varieties of Strawberries, an exam- 

 ination shows the absence of stamens. In other cases the stamens 

 may be present, and may shed pollen, but adequate examination 

 under a microscope together with tests for viability will readily 

 reveal the impotent condition of the pollen. 



ADAPTATIONS LIMITING SELF- AND CLOSE-POLLINATION 



The mention of adaptations for cross-pollination naturally 

 brings to mind the many varied and marvellous structural adapta- 

 tions for "cross-pollinations" by insects. But no matter how com- 

 plex these may be, as long as the flowers of the different individuals 

 of a species are alike and as long as there are numerous flowers 

 open on a plant at the same time structural adaptations of them- 

 selves do not prevent close-pollination (from flower to flower on 

 the same plant or from plant to plant of a clonal variety.) 



To take a seed-grown variety to illustrate this point, it is me- 

 chanically as easy for a bumble bee to carry pollen from the sta- 

 mens of a flower on a Red Clover plant to the pistil of another 



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