Abstract: | Maximum carrot seed dry weight and maximum endosperm volumewere reached about 35 d after anthesis, although at this timethe endosperm was still soft, the pericarp green and less than50% of the seeds were viable. Fully viable, ripe seeds werenot produced until 44 d later. Seventy per cent of the increasein endosperm volume was due to an increase in cell number, whichceased 35 d after anthesis. The increase in embryo volume wasslower and was due to an increase in both cell number and cellvolume which continued until 49 d after anthesis. At maturitythe embryo was the equivalent of between 2% and 3% of the endospermvolume. The relationship between embryo length and cell number per embryowas unaffected by seed crop plant density, seed crop harvestdate and position of the seed on the mother plant but it wasaffected by the year of seed production, possibly due to differencesin temperature during the period of seed growth. Key words: Endosperm, Embryo, Carrot, Development |