Effects of water supply and sowing date on performance and essential oil production of anise (pimpinella anisum l.)

TLDR: It was concluded that for higher grain and essential oil production, anise must be sown early in the spring (April 4 to 16 in Tabriz) because of water deficit during stem elongation and umbel appearance.

Abstract: Field and greenhouse experiments were carried out in order to determine the effects of water supply and sowing date on the performance and essential oil production of anise (Pimpinella anisum L.). The results indicated that mean leaf area (LA), specific leaf area (SLA), relative growth rate (RGR), relative water content (RWC), grain yield and essential oil decreased, while the root/shoot ratio and the oil percentage of the seeds increased when the available soil water decreased to below 80% in the greenhouse. It was concluded that for higher grain and essential oil production, anise must be sown early in the spring (April 4 to 16) in Tabriz. Water deficit during stem elongation and umbel appearance reduced anise growth, grain yield and oil production. Seeds harvested at the waxy stage had higher oil content than those harvested at earlier or later stages.