Effects of sowing date and plant density on flower yield and active substance in Chamomile (Matricaria chamomilla L.)

Chamomile is an annual plant that belongs to Asteraceae (Compositae)family. The flowers have an active substance which is called "essential oil". The most important constituent in essential oil is "chamazulene" that is used widely in pharmaceutical, food, perfumery and flavouring industries. The main aim of this study was determine the effects of sowing date and plant density on flower yield and active substance of Chamomile. The experiment was carried out at Khojir Research Station, in 1998. The treatments were three sowing dates (25 March, 4 April and 14 April) and three plant densities (5020, 5030 and 5040 cm). The experimental design was in randomized complete blocks with three replications (treatments were arranged in factorial combinations). Characteristics such as fresh and dried flower yield, essential oil content of flower, chamazulene percentage and essential oil and chamazulene yield. Mean comparison was carried out using Duncan Multiple Range Test (at 5% level). Results showed that the highest fresh and dried flower yield, essential oil yield, chamazulene percentage and chamazulene yield were obtained from the first sowing date (25 March). Plant density also showed significant effects on these characters (except essential oil in flower and chamazulene percentage). The highest fresh and dried flower yield, essential oil yield and chamazulene yield were obtained from the plant density (5020 cm). According to the results of this study‚ the best sowing date was 25 March and the most suitable plant density was 5020 cm