Influence of Bio-Stimulation and Micronutrients on Yield and Quality of Washington Navel Orange

This study was carried out during 2022 and 2023 in private farm in Rashid area, Beheira Governorate, on 15 years old Washington navel orange trees (Citrus sinensis, L.) budded on sour orange rootstock (Citrus aurantium, L.), to investigate the effect of bio-stimulation and micronutrients on yield and quality of Washington Navel Orange. The experiment design was a Randomized Complete Block Design (RCBD), with three replicates. The trees were sprayed three times; at the start of growing season in February, at full bloom (80% flowering) in March and one month after fruit set. Fifty-six trees as uniform as possible in size, productivity and appearance were selected for this study and The treatments of this experiment could be summarized as (Control, maringa extract at (2000, 4000 and 6000 mg/l), seaweed extract at (2000, 3000 and 4000 mg/l), fulvic acid at (1000, 1500 and 2000 mg/l), mixed of Fe + Zn + Mn at (500, 1000 and 1500 mg/l). The obtained results showed that all treatments enhanced all traits studied which increasing of concentrations of all treatments increased all this traits studied, which seaweed at 4000 mg/l recorded the higher fruit weight, yield/ tree, yield, fruit length, fruit diameter, fruit size and firmness, TSS, TSS/ Acidity, vitamin C, N, P and K, followed by, seaweed at 3000 mg/l and fulvic acid at 2000 mg/l, while mixture of Fe+Zn+Mn at 1500 mg/l recorded the higher Fe, Zn and Mn, as compared to control treatments which recorded the lower values of fruit weight, yield/ tree, yield, fruit length, fruit diameter, fruit size and firmness, TSS, TSS/ Acidity, vitamin C, N, P, K, Fe, Zn and Mn but control treatment recorded the higher acidity, during both seasons respectively.