The possibility of improving saffron (Crocus sativus L.) flower and corm yield through the irrigation and soil texture managements

In order to study the effect of soil texture and irrigation management on flower and corm yield of saffron (Crocus sativus L.), an experiment was conducted at research field of Agricultural Faculty of Sarayan, University of Birjand during two growing seasons (2013-2015). The study was performed as factorial based on Randomized Complete Block Design. Experimental factors were irrigation intervals (every one and two weeks equal to 3000 and 1600 m(3) . ha(-1) as normal and deficit irrigation, respectively) and soil texture (100 % soil, 75 % soil + 25 % sand, 50 % soil + 50 % sand, 25 % soil + 75 % sand and 100 % sand). Results of the first flowering season showed that maximum number of flowers (74.33 No. m(-2)) and yield of dry stigma (3.216 kg.ha(-1)) obtained in one week irrigation interval with 50 % sand + 50 % soil. The maximum values of these traits (308.2 flower per m(2) and 9.37 kg.ha(-1) dry stigma) during the second year were gained in one week irrigation interval with 75 % sand + 25 % soil. The highest amounts of large (>= 9 g) replacement corms number (111 and 200 No.m(-2)) and yield (11,289 and 21,582 kg.ha(-1)) were obtained by one week irrigation interval and 25 % sand + 75 % soil and 75 % sand + 25 % soil at the end of first and second growing seasons, respectively. Furthermore, one week irrigation interval increased replacement corms yield by 20 % compared with two weeks irrigation intervals in both growing seasons. Therefore, it was concluded that selection of moderate and light soil texture and shorter irrigation intervals (equal to 3000 m(3). ha(-1)) are important factors for improving flower and corm yield of saffron.