A two-season field experiment was conducted  investigate the effect of deficit irrigation treatments: 100% (D₁), 80% (D₂) and 60% (D₃) of the crop evapotranspiration (ET_c) and biochar application: 0.2 wt.% (B₁) and 0.4 wt.% (B₂) on the growth , water use efficiency (WUE) and Water Productivity (WP) of banana plant grown in sandy soil under drip irrigation. Results indicated that all bananas' vegetative growth parameters, and the fruit yield and its measured quality parameters were significantly impacted (P˂0.05) by treatments. Results showed that the highest yield of banana (36.20 and 36.38 ton/fed.) was recorded with D₁B₂ treatment in both seasons, while the lowest yield (21.23 and 21.73 ton/fed.) was recorded due to D₃B₁ treatment (60 % of ET_c + 0.2 wt.% biochar) in both seasons. The total soluble solids, total sugars, and starch contents of banana fruit exhibited significant differences between all treatments of deficit irrigation and biochar application while its total acidity was not significantly impacted in both seasons. The maximum values of WUE (4.65 and 4.90 kg / m³) were as associated with D₂B₂ treatment (80 % of ET_c + 0.4 wt. % biochar) in both seasons. The highest values of WP were associated with D₂B₂ treatment (9.57 LE/m³), followed by D₁B₂ treatment (8.15 LE/m³) while the lowest value of WP was due to D₃B₁ treatment in both seasons. This data indicates that combination of 80% of ET_c and 0.4 wt. % biochar has saved a significant amount of irrigation water (20% reduction in irrigation water) without a compromise over neither the banana yield nor its fruits quality.