Fruit yield, essential oil concentration and composition of three anise cultivars (Pimpinella anisum L.) in relation to sowing date, sowing rate and locations

Three field experiments were conducted to evaluate the effect of sowing date and plant density on phenology, fruit yield and essential oil quality of three anise cultivars (Pimpinella anisum L.) at two different ecological conditions Gross-Gerau and Giessen, Germany. The experiments were designed as RCBD under factorial plot arrangement with two factors: cultivars in main plot and plant densities in sub plots realized in two sowing dates. Results showed that aniseed sown on April 1st had higher fruit yield in comparison with two weeks delayed sowing. Delayed sowing induced strong effects on yield contributing parameters such as branches/plant, umbels/plant, fruits/plant and 1000-fruit weight which were all reduced. The highest fruit yield was related to lower plant densities of 39 plants m−2 (Giessen) and 200 and 374 plants m−2 (Gross-Gerau). Higher plant density reduced branches/plant, umbel/plant, fruits/plant and 1000-fruit weight and led to lower fruit yield. The essential oil concentration of anise fruits was not affected by different levels of plant densities. A higher concentration of essential oil was synthesized in delayed sowing date in Gross-Gerau 2009 as compared to earlier sown anise plants. The essential oil concentration of anise showed no remarkable variation regarding sowing date and plant density. Cv. Hild Samen synthesized a significant higher concentration of estragol and trans-anethole. From all tested cultivars cv. Hild Samen was characterized by lowest fruit yield as well as lowest essential oil concentration. For successful cultivation, aniseed should be sown as soon as possible in April with a plant density of 50–200 plants/m2 considering soil conditions.

► We clarify the effect of fruit yield, essential oil content and composition of anise cultivars (Pimpinella anisum L.) in relation to sowing date, sowing rate and locations.
► We examine the effect of different plant densities on growth, yield components and quality parameters of aniseed.
► Essential oil content depended on environmental conditions rather than sowing times.
► A tendency of higher trans-anethole was observed in narrow plant densities due to higher fungal infection.