Effect of umbel position on dill (Anethum graveolens L.) plants growing in field stands on selected seed stalk features

Research was carried out on the effect of the umbel position on the ‘Amat’ dill (Anethum graveolens L.) plant on selected features of the seed stalk in the years 2002-2004. Commercial seeds of the species were sown on a small production field and grown for the purpose of producing seeds. Out of the field plant stands, three hundred plants were randomly selected. The following morphological features were then measured in respect to the seed stalk architecture in these plants: the length of the seed stalk, number of branches with primary, secondary and tertiary umbels, length of branches with primary umbels, as well as the main and primary umbel diameters. In addition, seed yield per plant, the weight of 1000 seeds, germination capacity, seed length and width, seed embryo and endosperm lengths for seeds from the main and primary umbels were also calculated and measured. Additionally, the main and primary umbels were divided into three parts: external, middle and internal, and seeds from each were examined separately. The position of the umbel on the seed stalk did not affect the number of branches with primary, secondary, and tertiary umbels on the dill plant and had no effect on its seed stalk architecture. There was no significant difference within the position of the main and primary umbels on the seed stalk grown in field stands. The diameter of the main umbel was the same as the primary one. The lower its position on the seed stalk, the lower the seed yield and germination capacity. The best seeds, in terms of their 1000 seed weight, came from the external part of the main umbel. The different localisation of seeds within the three designated parts of the main umbel had no effect on seed length or width or on their endosperm and embryo lengths. The recorded seed embryo length from the internal part of the primary umbel was smaller than its values from the two other parts of that umbel.