Seedling emergence is one of the most important factors in the establishment of optimum plant density for a maximum yield. Seed quality and seedbed conditions affect seedling emergence. Seedbed condition is affected by soil content, especially soil organic ma�er. Therefore, the objective of this study was to determine the effects of soil organic ma�er on germination and seedling emergence of three hybrid sunflower (Helianthus annuus L.) cultivars. This research was conducted in 2000 and 2001 in field and glasshouse conditions. Perlite and 20 soils with different organic ma�er contents were used as seedbed conditions. Soil organic ma�er, environment, and soil organic ma�er × environment factors had significant effects on seedling emergence. Decreasing soil organic ma�er content resulted in a decrease of seedling emergence due to the decreases in water content of the soil. This effect was clearer in adverse environmental conditions, especially in the soils with less than 2% organic ma�er.

The aim of this study was to investigate the possibility of cultivation of lemon balm (Melissa officinalis) in the Thrace region of north-western Turkey, which has a rich flora with many medicinal and aromatic plants. The study evaluated two propagation methods (cuttings with roots and seedlings) and three row spacings (40 × 20 cm, 40 × 30 cm, and 50 × 30 cm). Measurement of herb fresh and dry weight, leaf dry weight, and essential oil content helped to determine the effect of propagation method and row spacing on lemon balm yield. Yields were higher in the second year than the first year. Propagation from seedlings was better than cuttings. The highest dry herb yield (11167 kg/ha) was obtained in the second year of production at 40 × 20 row spacing using seedling propagation. Essential oil percentage (0.20-0.28%) did not significantly vary with treatments and years. Therefore, 40 × 20 cm row spacing and propagation from seedlings are recommended to optimise production in the Thrace region.