Influence of hydrogel composite applications and irrigation intervals on the yield and fruit quality of Valencia orange ( Citrus sinensis L.) trees under semi-arid conditions

Purpose: Under fluctuations in climatic conditions, sustaining production with excellent fruit quality is the main objective of citrus producers in the arid regions. This experiment was conducted on twelve-year-old Valencia orange trees (Citrus sinensis L) budded on Volkamer lemon rootstock (Citrus volkameriana), cultivated in sandy soil in the Eastern Desert of Egypt. Research method: This work studies the influence of hydrogel and irrigation intervals on the growth, yield, and fruit quality of Valencia orange trees. The experiment consists of four levels of hydrogel (0, 750, 1000, and 1250 g/tree) with three irrigation intervals (daily, day-by-day, and every 2 days) during three seasons (2020-2022). Findings: All applications affected tree canopy volume, shoot length, leaf number, yield (kg/tree), and the physical and chemical fruit characteristics. While, the application of 1000 g/tree hydrogel and every two-day irrigation interval produced the highest values when compared to other treatments during the experimental seasons. With respect to yield and fruit characteristics, treatment of 1250 g/tree hydrogel with irrigation day-by-day resulted in the highest tree yield (113.58 kg/tree) and total yield (18.74 tons/feddan) and improved various physical and chemical fruit characteristics. Research limitations: There was no limitation. Originality/Value: Hydrogel applications mitigated the impact of prolonging irrigation intervals on the vegetative growth, productivity, and fruit quality of the Valencia orange trees compared to untreated trees.