**7. Irrigation and water-deficit application**

All plants were irrigated every day for 15 minutes at 10:00 and 13:00 h. The irrigation within the greenhouse was performed by a microsprinkler system, with a flow rate of 10 L h–1. The three cycles of moderate stress were induced by irrigation suspension for four days at 25, 35, and 45 days after seedling emergence, whose periods coincided with the phenological stages V3, R6, and R8, respectively. In the cowpea crop, these periods described are related to vegeta‐ tive, flowering, and pod filling stages, respectively (Figure 5).

**Figure 5.** Seed placed into substrate (A); *V. unguiculata* seedling (B); plants with 14 days (C); trifoliate leaf (D); data obtained during experiment (E); infra-red gas analyzer (F).
