ABSTRACT
During 2013/ 2014 and 2014/2015 seasons, Valencia orange trees received three sprays; at growth start, directly after fruit
setting and after one month with three plant oils; clove, ginger and turmeric each at 0.025 ,0.05 and 0.1% besides the control
treatment. Treating the trees three times with oil of clove, ginger or turmeric each at 0.025 to 0.1% effectively stimulated yield,
fruit quality, leaf area and leaf content of pigments, N, P, K and Mg comparing with the control treatment. The promotion was
related to the increase in concentrations of these plant oils. Negligible stimulation on all the previous parameters was revealed
among the higher two concentrations namely 0.05 and 0.1% . Using oils of clove, ginger and turmeric was effective in an
ascending order in this connection. It could be concluded that spraying Valencia orange trees grown under Assiut region
conditions with turmeric oil (0.05%) three times resulted in the highest yield and the best fruit quality.