Saffron yield and quality as influenced by different irrigation methods

ABSTRACT Dried stigma of saffron is the most expensive spice in the world. In Iran, the majority of saffron farms use the traditional basin method for irrigation, which, together with other irrigation methods may soon face serious problems because of droughts in the future. Making an evaluation of the regional crop response to the irrigation method is important to the adoption of a proper irrigation management strategy. In this study, the effect of employing different irrigation methods, including the sprinkler, drip, furrow, and basin, on the following factors was evaluated: the saffron stigma dry weight, quality, water use efficiency (WUE), and Irrigation water use efficiency (IWUE) in the arid climate of Qaen, South Khorasan, Iran, over three consecutive crop years. The experiment was undertaken using a randomized complete block design with three replications. The results showed that seasonal saffron Evapotranspiration (ETC) was recorded as 356.5, 339.1, and 330.7 mm, in 2003, 2004 and 2005 respectively, as a result of administering the treatments. Saffron yield as well as WUE and IWUE were found to respond to the various irrigation methods except in the first year. In total, maximum stigma dry weight and water use efficiencies were reached in the third growing season using the drip irrigation method. Judging by the results, the drip irrigation method for saffron production is to be preferred. Additionally, the quality level of saffron was found to be acceptable. However, due to higher crocin content, the quality of saffron irrigated by the sprinkler method was somewhat higher.