EFFECT OF SOWING PERIOD ON SEED YIELD AND ESSENTIAL OIL COMPOSITION OF CORIANDER (Coriandrum sativum L.) IN SOUTH-EAST BULGARIA CONDITION

Coriander (Coriandrum sativum L.) is one of the most important spice and aromatic plants grown worldwide. It is an annual plant, belonging to the Apiaceae family, which is cultivated mainly for its fruits (seeds). The productivity of coriander is influenced by weather conditions, agronomic and genetic factors. In this paper the influence of six sowing periods (October, November, December, February, March and April) on yield and essential oil quality of the coriander cultivar 'Alekseevski' is discussed. The study was carried out during 2015-2018 in south-east Bulgaria on vertisols leached soil type. Field experiments were performed by means of a block method with four replications; experimental field area was 15 m(2). The pre crop of coriander was winter wheat. All the stages of the established technology for coriander growing were followed. The indicators seeds yield (kg ha(-1)), essential oil content (%), essential oil yield (kg ha(-1)) and essential oil composition of coriander were determined. The obtained data was statistically processed by the dispersion and correlation analyses methods. The obtained results showed that sowing period in combination with meteorological conditions during the years of the study had a significant influence on productivity of coriander, grown in the study. The highest seeds and essential oil yields (2302 kg ha(-1) and 26.8 kg ha(-1), respectively) in the October sowing period were reported, and the lowest ones (1582 kg ha(-1) and 11.8 kg ha(-1)) in the April sowing was recorded. The essential oil content in coriander fruits was lower by the later sowing period. The year of the experiment and sowing period affected essential oil composition.