SHAW: FERTILIZATION OF BEETS I5I 



known that no other beets were grown. The highest percentage 

 of seed produced among these plants was 2.29; several of the 

 plants remained entirely sterile, although otherwise their growth 

 was normal. 



After ascertaining that beet pollen can be preserved for a 

 considerable time, experiments involving hand pollination and 

 isolation with paper bags were carried out to determine con- 

 clusively whether the protandrous character of the beet flower 

 might be overcome by separately preserving the pollen of indi- 

 vidual flowers, collected when the anthers dehisced, and applying 

 the pollen to the appropriate flowers when the respective stigmata 

 had become receptive. This was done with several hundred! 

 flowers on numerous beets. All flowers thus self-pollinated/ 

 remained sterile. 



In addition, various types of close pollination were made, the 

 work being distributed among many plants. For example: The 

 pollen taken from flowers on one spike was applied to the receptive 

 stigmata of other flowers on the same spike. Of these flowers 

 2.63 per cent were fertilized and produced seed; in addition, the 

 carpels of 5.23 per cent of the flowers enlarged without forming 

 seed. 



The application of pollen from flowers on one spike to the 

 stigmata of flowers on another spike on the same stem resulted 

 in an average fertilization of 5.23 per cent, and a carpel stimu- 

 lation of 5.8 per cent. 



The transfer of pollen from flowers of one stem to the stigmata 

 of flowers on another stem of the same plant resulted in the 

 fertilization of 8.54 per cent of those flowers and the carpel 

 stimulation of 3.47 per cent. 



Per cent of Per cent of carpels 

 fertilization stimulated 



1. Self pollination: pollen to stigma of same flower. . . o.oo o.oo 



2. Close pollination: pollen of one flower to stigma 



of another flower on same spike 2.63 5.26 



3. Close pollination: similar to No. 2, but with 



modified technic 2.70 1.43 



4. Close pollination: pollen of flower on one spike 



to stigma of flower on another spike of same 



stem 5.23 5.80 



5. Close pollination: pollen of flower on one stem 



to stigma of flower on another stem of same 



plant 8.54 3.47 



6. Close pollination: of plants isolated by distance. . . 0,00 to 2.29 



7. Cross pollination 100.00 possible. 



