Hydrogel technology increases resilience of Inga edulis seedlings under drought conditions

Technologies that can mitigate the stressful effect of water deficit and assist in seedling recovery are necessary. This study aimed to evaluate the effect of hydrogel doses on mitigating water deficit stress and the recovery of Inga edulis Mart. seedlings in the post-stress period. The seedlings were grown under the following water management regimes: control - daily irrigation; water restriction (WR) - seedling irrigation suppression + 50 mL of Hydrogel (H); WR + 100 mL of H, and WR + 150 mL of H. The seedlings were evaluated in two periods: P0 - when the photosynthetic rate (A) of the seedlings of at least one of the treatments subjected to irrigation suppression with or without hydrogel reached values close to zero; REC (recovery) - after P0 in the seedlings of each treatment, irrigation was resumed until the seedlings previously subjected to WR of each treatment reached values of A ≥ 50% to that of the control seedlings. Adding 100 mL of hydrogel delayed the stressful effect of water deficit on the photosynthetic rate. Furthermore, it assisted in a more rapid post-stress recovery while keeping the Rubisco carboxylation efficiency high upon recovery.