Athraa Khairi Abd Oun
University of Baghdad, Iraq
Shaim'a Thiab Abed Habeeb
Al-Karkh University of Science, Iraq
Background: Orange (Citrus sinensis) cultivation is often hindered by soil and water salinity, a major abiotic stress in arid and semi-arid regions. Gibberellic acid (GA), a plant growth regulator, is known to enhance plant growth and mitigate stress-induced damage.
Objective: This study investigates the individual and combined effects of irrigation water salinity and exogenous GA application on the growth of orange seedlings under controlled conditions.
Methods: A two-factorial completely randomized design (CRD) was employed, comprising three levels of salinity (Low, Medium, High) and three concentrations of GA (0 ppm, 50 ppm, 100 ppm). A total of 90 seedlings were evaluated for growth (height in cm) after treatment.
Results: ANOVA results indicated significant main effects of both salinity (p < 0.001, ?² = 0.507) and GA (p < 0.001, ?² = 0.320) on seedling height. However, the interaction effect was not statistically significant (p = 0.127). The highest growth was observed in seedlings treated with 100 ppm GA under low salinity, while the lowest occurred under high salinity without GA.
Conclusion: The findings confirm that both reduced salinity and GA application significantly enhance citrus seedling growth independently.
This study provides empirical support for integrating plant growth regulators with salinity management strategies to improve citrus production under stress conditions.
