Abstract
Saffron (Crocus sativus L.) is a precious crop belonging to the family Iridaceae and is one of the most expensive spices with many medically important bioactive molecules. It is among the richest plant sources of riboflavin, essential oil, and carotenoids. To study the impact of planting date on saffron productivity, morphological traits, crop yield, and bioactive constituents, a field experiment was conducted in a semi-arid climate at the experimental field of Prince Sattam bin Abdulaziz University, Alkharj, Saudi Arabia, for seasons 2013 and 2014 based on a randomized complete block design with three planting dates (T1: 25 Sept., T2: 09 Oct., and T3: 23 Oct.) using three replicates. Our findings show a significant difference in phenology and bioactive contents between T1, T2, and T3. The variations in the number of sprouts corm(-1) (17.61 +/- 2.81), the number of leaves sprout(-1) (3.45 +/- 0.38) and the length of the longest leaf plant(-1) (34.83 +/- 2.79 cm) were maximum in T1 for both seasons, followed by T2. Similarly, the stigmata (0.15 +/- 0.02 g plant(-1)), stamen (0.15 +/- 0.011 g plant(-1)), and tepal (0.2 +/- 0.01 g plant(-1)) fresh weights and flower dry weight (0.19 +/- 0.02 g plant(-1)) were measured in T1 in both seasons. No flowering was induced in T3 in either season. The chemical profiling also showed differences in the crocin and safranal contents using HPLC and a spectrophotometer. The crocin content peaked in the stigmata of T1 and ranged from 0.015 +/- 0.0009 to 0.02 +/- 0.001 mg mg(-1) DW in the 2013 and 2014 seasons, respectively. Similarly, the safranal content ranged from 0.03 +/- 0.0009 to 0.054 +/- 0.002 mg mg(-1) DW in the 2013 and 2014 seasons, respectively. Based on the current planting date, we report for the first time the establishment of the cultivation of C. sativus in the desert of Saudi Arabia.