Two field experiments were carried out at a private farm, Damietta, Egypt to study the effect of foliar application and fertigation on the biological aspects as (plant height, number of leaves and root length and plant growth biomass (i.e., fresh and dry and shoot/root ratio and relative growth rate) as well as chlorophyll contents of pepper. Four foliar potassium treatments ((K₀ (control), K₁; 2kg fed^-1 , K₂; 4kg fed^-1, and K_3; 6kg fed^-1) ) combined with three fertigation treatments (K₀ (control), K₁; 66kg fed^-1 K₂; 132kg fed^-1) were arranged in a split-plot design with three replicates. The results showed that plant height and root length increased significantly by potassium fertigation and foliar application compared to the control. In contrast, potassium fertigation and foliar application had no significant effect on leaf area and leaf area index in both seasons. Pepper fresh and dry weights decreased by increasing K fertigation compared to the control, while potassium foliar application (K-leaf) significantly increased pepper fresh and dry weights with increasing potassium compared to the control except with the treatment of 6 kg fed^-1 in both seasons. Potassium fertigation and foliar application had no significant effect on chlorophyll A, B, total carbohydrates and total phenols. While vitamin C increased by increasing potassium fertigation. The treatment of 50% in the recommended dose recorded the highest vitamin C values in both seasons and the potassium foliar application with K- leaf at the rate of 4 kg k fed^-1 gave the highest vitamin C values in both seasons.