The present study carried out on fruitful Washington Navel orange trees 12 years old, budded on sour orange rootstock grown in clay loamy soils in private farm at Toukh region, El-Kalubeia Governorate to evaluate response the trees productivity to foliar spray with some stimulating compounds at two concentrations for each i.e., yeast extract at 2.50 ml/l & 5.0 ml/l, sea weeds at 0.2 &0.4 ml/l, promalin at 100 & 200 ppm and humic acid at 3.0 & 6.0 g/l and mixture of lower concentration of each substance, beside control which sprayed with tap water during 2019 and 2020 seasons. The results indicated that, treatments significantly increased yield indicators and improved fruit quality compared to control. Promalin at 200ppm or yeast extract at 2.5 m/L+ sea weeds extract at 0.2m/L + promalin at 100 ppm gave highest values of yield measurements and fruit quality.