Two field experiments were conducted during 2016 and 2017 summer seasons in a private farm near El-Mahalla El-Kobra, El-Gharbia governrate to evaluate the effect of three NPK levels (100, 75 and 50 percentage of NPK recommended dose) and NPK foliar application (with or without foliar NPK spraying) with three foliar activators applications (chitosan, moringa leaf extract and lithovit) as well as  tap water as a control and their interactions on vegetative growth characters, ion percentage, yield and its quality of cucumber plants cv. prince. Obtained data revealed that 100 % of recommended NPK (120 kg N, 50 kg P₂O₅, 100 kg K₂O/fed.) and foliar application with NPK at 3 g/l  combined to foliar application with chitosan at 3 g/l  gave the highest values of yield and its components i.e. (number of fruits, fruit yield/ plant, early and total yield/fed.), while 75% NPK of recommended dose (90 kg N, 37.5 kg P₂O₅, 75 kg K₂O/fed.) plus NPK foliar application with spraying moringa leaf extract at 10 ml/l gave the highest values of vegetative growth parameters i.e. (number of leaves/plant, shoot fresh and dry weight, plant height), also chitosan at 3 g/l combined with foliar NPK and 75% of NPK recommended dose as soil application gave superiority in N, P and K percentage in cucumber leaves, in addition, total sugar, TSS and total chlorophyll in cucumber fruits. Thus, it can be recommended that use 75% NPK from recommended dose plus foliar application NPK and foliar spray with moringa leaf extract applications to decrease mineral fertilization which reflected on reducing production costs and mitigate the environmental pollution and protect the human health.