Cut-off irrigation as an effective tool to increase water-use efficiency, enhance productivity, quality and storability of some onion cultivars

Water management is becoming commonplace in discussions of high-yield farming and modern agricultural best practices. A field experiment undertaken in the Northern region of Egypt, Kafr El-Sheikh Governorate, with four cut-off furrow irrigation treatments (100%, full irrigation – considered as a control; 90%, 80% and 70% of strip length) was used to compare the effects of reduced water supply on onion (Allium cepa, L.) production via assessing three different cultivars (e.g., Giza red, Giza 20 and Behairy red). A strip-plot design with three replicates was employed in this regard during two successive seasons (2014–2015/2015–2016). Regardless of onion type, water supply at 80% level resulted in higher marketable and total bulb yield (t/ha) with improved quality traits and storability compared to other irrigation treatments. There have been few significant interspecies differences. The most notable significant differences were recorded in Giza red and Behairy red for all studied characteristics. The highest results were reached with Giza red under the use of 80% irrigation level. In addition to the excellence in improving the overall quality and harvestable yield, this treatment (80% watering) has produced relatively good results with respect to the consumptive water-use efficiency, water productivity and showed significant benefits in terms of saving irrigation water. Maximum water saving was obtained under the use of 70% irrigation treatment, but in the absence of a good and economically unacceptable yield. The traditional technique (100% water supply) consumed much water, surpassing the most effective treatment (80%) by 1195.77 cubic meter per hectare (i.e., 11.96 cm in depth/height). In conclusion, cut-off irrigation technique is considered an efficient and effective intervention approach for onion yield increases while maintaining post-harvesting quality and water savings. However, extending the study beyond onion is critical to increase the range of benefit with regard to other crops, as well for adequate management of water under deficit irrigation conditions.