Morpho-physiological parameters, nutritional status and water use efficiency of Zebda mango in relation to biochar and hydrogel application under semi-arid region

Irrigation water conservation techniques are an effective tool for maximizing irrigation water utilization, especially in coarse sandy soils under semi-arid conditions. Therefore, the objective of this research was to investigate the impacts of soil application of biochar (BC) at 7, 14 kg tree^{- 1}, hydrogel (HD) at 50-100 g tree^{- 1} and without application (control) on the morpho-physiological, nutritional status and productivity of Zebda mango trees during two seasons. Results indicated that, soil application of 14 kg BC tree^{- 1}, followed by 100 g HD tree^{- 1} was more effective in enhancing growth and fruit yield. BC at rate of 14 kg tree^{- 1} increased number of leaves by a percentage reached to 22.27 and 32.05%, leaves area by 18.51 and 18.51, shoot length by 21.19 and 17.95% and chlorophyll content by 81 and 51%, while it decreased leaves proline content by 9.15 and 13.78% compared to the control in the first and second seasons, respectively. Moreover, 14 kg BC increased leaf N concentration by 42.98 and 27.2%, leaf P by 75 and 47.62%, leaf K by 5% and 9.64% and leaf Mg by 27 and 6% compared to the control in the first and second seasons, respectively. Also, it improved the percentage of final fruit set by 50% and 38.09%, number of fruit by 29.47% and 22.19%, fruit weight by 20.46% and 12.76%, and increased both fruit yield and water use efficiency by 55.98 and 37.79%, while it decreased fruit drop by 2.79 and 2.16% compared to the control in the first and second seasons, respectively. Furthermore it increased the percentage of TSS by 17.09% and 18.27%, titratable acidity by 21.43% and 12.63%, ascorbic acid by 23.56% and 18%, and total sugars by 27.92% and 3.19% compared to the control in the first and second seasons, respectively.