Yield, quality, and growing degree days of anise (Pimpinella anisum L.)under different agronomic practices

Abstract

Abstract: Two-year field experiments in a randomized complete block design with a split-plot arrangement in triplicate were performed in the 2013 and 2014 growing seasons under the Isparta ecological conditions of Turkey. The aim of the study was to determine the effects of sowing dates (15 March, 1 April, 15 April, and 1 May) and row spaces (15, 20, and 25 cm) on seed yield, yield-related traits, essential oil content, chemical composition, and growing degree days (GDD) of anise. The anise population of the study was obtained from Burdur, Turkey. The seed yield and its components, including plant height, number of branches, and number of umbels per plant, decreased due to delayed sowing time in 2013 and 2014. However, the highest essential oil content was obtained from the 15 April sowing date in both years. Among the row spaces, 20- and 25-cm row space resulted in the highest yield, yield components, and essential oil content both in 2013 and 2014. The effect of the sowing date and the row space interactions on seed yield and some yield-related traits of anise was statistically significant in both years. Generally, the yield and its components were higher when the row space was wider, as occurred on 15 March and 1 April, the early sowing dates of both 2013 and 2014. The highest essential oil content was obtained from the 20-cm row space on 15 April, the third sowing date, in both years. The main components of anise essential oil were determined as anisole-p-allyl (1.28%-1.80%), caryophyllene (1.00%-1.30%), and trans-anethole (96.95%-97.57%). Growing degree-days for different sowing dates of anise, from emergence to harvest, were 1413.5-1717.6 °C in 2013 and 1405.5-1686.1 °C in 2014.