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.

摘要：藏红花（saffron）干燥柱头是全球最为昂贵的香料。伊朗境内多数藏红花种植园采用传统盆式灌溉法，受未来干旱气候影响，该方法与其他多数灌溉手段或将很快面临严峻挑战。评估区域作物对灌溉方式的响应，对于制定合理的灌溉管理策略至关重要。本研究于伊朗南呼罗珊省盖延（Qaen）的干旱气候区，连续三个作物生长季，评估了喷灌、滴灌、沟灌及盆式灌四种不同灌溉方式对以下指标的影响：藏红花柱头干重、品质、水分利用效率（water use efficiency, WUE）及灌溉水利用效率（irrigation water use efficiency, IWUE）。本试验采用随机完全区组设计，设置三次重复。结果显示，经各处理后，2003、2004、2005年的季藏红花蒸散量（evapotranspiration, ETC）分别为356.5、339.1和330.7毫米。除首个生长季外，藏红花产量、水分利用效率及灌溉水利用效率均随灌溉方式的不同呈现显著差异。综合来看，第三个生长季采用滴灌方式时，藏红花柱头干重及水分利用效率均达到最大值。综合试验结果可知，藏红花种植中优先推荐采用滴灌方式。此外，各处理下藏红花的品质均符合合格标准；但由于喷灌处理的番红花苷（crocin）含量更高，其品质表现略优。