Uso de água salobra no crescimento, trocas gasosas e na produtividade da cultura do gergelim sob estratégias de adubação mineral, orgânica e organomineral

Abstract

em língua inglesa*: Sesame (Sesamum indicum L.) cultivation has attracted increasing interest due to its high nutritional value and potential for integration into different production chains. However, the quality of irrigation water represents one of the main challenges to crop productivity due to high salt concentrations, especially in semi-arid regions. Therefore, the use of sustainable strategies for managing mineral, organic, and organomineral fertilization has been explored as an alternative to mitigate the adverse effects of saline stress. Thus, the objective was to evaluate the use of brackish water on the agronomic performance of sesame under mineral, organic, and organomineral fertilization strategies. The experiment was conducted in a greenhouse at the Federal University of Ceará. A completely randomized experimental design (CRD) was used, in a 6 × 2 factorial scheme, with 4 replications, corresponding to six fertilization strategies in the phenological phases: E1 - 100% shrimp biofertilizer (CB) (until capsule formation); E2 - 70% CB (in the vegetative growth phases) + 30% NPK (flowering and capsule formation); E3 - 50% CB (in the vegetative growth phase) + 50% NPK (flowering and capsule formation); E4 - 100% NPK (until capsule formation); E5 - 70% NPK (in the vegetative growth phases) + 30% CB (flowering and capsule formation); E6 - 50% NPK (during vegetative growth phases) + 50% BC (flowering and capsule formation) and two irrigation water electrical conductivity levels (0.8 and 3.0 dS m-1). Growth variables, leaf gas exchange, and yield were evaluated. Saline stress reduced growth, gas exchange, and sesame productivity. The isolated use of shrimp biofertilizer favored vegetative growth but reduced productive components. Strategies E4, E5, and E6 provided better physiological performance. Strategies E4 and E5 showed lower productivity losses under higher salinity (34% and 39%), and the combination of mineral fertilizers and shrimp biofertilizer (E2, E5, and E6) proved promising for mitigating the effects of saline stress and increasing productivity in non-saline conditions.