Document Type : Articles
Authors
Department of Horticulture, College of Agricultural Engineering Sciences, Salahaddin University-Erbil, Iraq
Abstract
As agriculture in Iraq faces the challenges of climate change, particularly given the preference for consuming local vegetables, determining the drought tolerance of indigenous varieties and developing strategies to mitigate its impact have become a top research priority. The aim of this study was to mitigate the impact of water potential during the germination stage of a local variety of onion (Allium cepa L. var. local white) that is cultivated and consumed widely in the Kurdistan region of Iraq. Ascorbic acid (Asc) with two concentrations (1.5 and 2.5 mM) as a priming compound and polyethylene glycol 8000 (PEG8000) with concentrations (50 and 100 g/L) as a water potential inducer were implemented for different durations (12 and 24 h). Onion seed germination and growth characteristics were recorded. Germination energy at four days (GE4) and germination capacity (GC) were improved when seeds were treated with 1.5 mM Asc for 12 hours. The highest germination rate index (GRI) of 9% and the shortest mean germination time (MGT) were recorded when seeds were treated with 3 mM Asc, while direct sowing had the lowest GRI of 6.5%. The values of radicle and hypocotyl growth were recorded the highest when seeds were primed with 1.5 mM Asc for 12h and exposed to 50 g/L PEG8000. These results indicate the important role of Asc priming under moderate water potential in improving onion seedling growth and resilience. We recommend that farmers in Kurdistan and Iraq adopt Asc priming techniques to enhance drought resistance in onion crops. Future research should focus on optimising Asc concentrations and exploring additional stress-mitigation strategies for other key crops in the region.
Keywords
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