International Journal of Scientific and Technological Research www.iiste.org ISSN 2422-8702 (Online), DOI: 10.7176/JSTR/6-01-06 Vol.6, No.01, 2020 60 | Page www.iiste.org Determining The Effect of Diurnal Variability on Some Yield and Quality Characteristics of Saffron ( Crocus sativus L.) Kaan Erden (Corresponding author) Agricultural Faculty, Department of Field Crops, Harran University, PO box 63150, Sanliurfa, Turkey E-mail: erdenk@harran.edu.tr Abdulhabip Ozel Agricultural Faculty, Department of Field Crops, Harran University, PO box 63150, Sanliurfa, Turkey E-mail: hozel@harran.edu.tr Abstract This study was conducted to determine the effect of diurnal variability on yield and quality characteristics of saffron (Crocus sativus L.) under the conditions of Harran Plain on research fields of Faculty of Agriculture of Harran University during winter growing seasons in 2006-2007 and 2007-2008. The trial was arranged in randomized complete block design with three replicates. For determining the effect of diurnal variability, three different flower harvest times were used in the research: 07.00 hours, 12.00 hours and 17.00 hours. The following parameters including plant heights (50.47 - 50.73 cm), stigma lengths (3.44 – 3.47 cm), stigma weights (7.55-7.57 mg), saffron yields (1958.7-1959.5 g daˉ¹), safranal ratio (‰ 37.57-39.93), crocin ratio (‰192.5-200.0), picrocrocin ratio (‰86.97-89.63), corm numbers per plant (4.77–4.87 number plantˉ¹), corm yields (3663.0-3669.0 kg daˉ¹) and marketable corm ratios (%70.90-71.67) were determined in the study. As a result, it was recommended that the saffron should be harvested at 07:00 and at the day of full flowering under Harran Plain conditions. Keywords: Saffron, Crocus sativus, Diurnal variability, Crocin, Safranal, Picrocrocin DOI: 10.7176/JSTR/6-01-06 1. Introduction Saffron (Crocus sativus L.) is a plant known since ancient times and used as a spice and sweetener in food and beverage industry and also in medicine, cosmetic and dye industries due to its fragrance, color and taste. Homer and Hippocrates, ancient Greek, Roman and Egyptian Civilizations reported the common use of saffron in dyeing, perfume, medicine and as spice in foods-beverages (Gümüşsuyu 2003). In addition, it is used in the mixtures of products in food industry including cakes, cookies, biscuits, confectionery, delight, soup, chicken, baked bakery products, sauces, desserts, cheese and butter, and people regard it as an indispensable component of rice, soup and meat dishes and some traditional deserts like Zerde (Leung 1980; Douglas & Mc Gimpsey 1993; Koç 2002). In traditional and modern medicine and pharmaceutics, it is used as stimulant, appetizing, aphrodisiac, for strengthening heart muscles, sedative, dysentery preventive, therapeutic, expectorant, crisis and pain- relieving, freckles and acne remover, constipation agent, stomach strengthening, for the complaints of gout, bronchitis and cough, anti-depressant, anti-spasmodic, for the treatment of gynecological diseases and anti-tumor effects. Furthermore, it is included in the composition of medicines used against fever, measles and splenomegaly (Baytop 1984; Şekercioğlu 1999; Demirhan 2002; Koç 2002). Saffron, Crocus sativus L. has desiccated stigmata and contains fixed oil (5.9%), volatile oil (0.4-1.3%), protein (11%), water (11.9%), carbohydrate (64.4%), fiber (3.9%), ash (5.4%) (111 mg Ca, 11 mg Fe, 252 mg P, 1724 mg K, 148 mg Na) and B2 vitamin (Riboflavin). The most important component of volatile oil is the aldehyde known as safranal (turpenic) (47%), which gives saffron its distinctive spice scent. The bitterness of saffron derives from colorless picrocrocin (4%). The peculiar color of saffron results from crocin (%24-27). Crocin is a bright yellow component and allows saffron to paint 100.000-150.000 times more than its own weight (Koç 2002). The amount of this agent which enables saffron to be used as spice