Factors affecting seed set in brussels sprouts, radish and cyclamen

If brussels sprouts were, self-fertilized, seed setting increased with age of the flower buds until a maximum some days before buds opened. After that, set decreased rapidly. Warmth shortened the period over which selfing was possible and shortened the period to the opening of the flowers. Most seeds occurred in 7-9 mm long buds.In crossing, seed set did not decrease just before flowers opened. Warmth shortened the fertilization period. Before flower opening a period (shorter with warmth) existed during which selfing and crossing gave the same results. Crossing after opening of the flowers first increased seed set, later decreased it. This fertilization period was also shortened with warmth.The inhibition of pollen germination by the style of incompatible plants occurred some days before opening of the buds. With opening it reached a maximum, after that it decreased and disappeared. Application ofα-naphthylacetamide did not overcome incompatibility.The data on pollination period of radish only showed a few differences from those on brussels sprouts.Cyclamen had no incompatibility. Fruits always contained seeds. Many peduncles rotted prematurely and many fruits were lost. Emasculation favoured this rotting and in some varieties decreased the number of seeds per fruit. Application of alfa-naphthylacetamide after castration increased seed -set, stimulated elongation of the peduncles and decreased rotting.