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.

The experiments comprising 25 sunflower hybrids were conducted in three locations in 2000 and 2001. These hybrids were evaluated for combining ability of 6 important yield components. Based on observations in this research, the average flowering duration of the hybrids ranged from 69.6 to 71.8 days, physiological maturity from 98.7 to 104.2 days, hectoliter weight from 355.2 to 408.5 g, 1000-seed weight from 32.5 to 43.5 g, plant height from 98.3 to 134.3 cm and head diameter from 12.6 to 14.0 cm. Based on all combining ability analyses performed in this research, the cross 2453-A × R-1001 was determined as the best hybrid in the experiment. Among the parental lines, HA89-A and 2644-R were chosen as first female and male testers, respectively; BAH8-A and 2280-R were chosen as second testers for testing combining ability of lines for use in future breeding programs in sunflower.

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