CRESCIMENTO E PRODUÇÃO DE MATÉRIA SECA EM CULTIVARES DE GERGELIM SOB DÉFICIT HÍDRICO
joao marcos sousa de oliveira
UFERSA
Ivan Euzébio da Silva
UFERSA
João Everton Da Silva Ribeiro
UFERSA
Aurélio barros Junior
Lindomar Maria Da Silveira
UFERSA
Palavras-chave: Sesamum indicum L., Estresse hídrico, Fisiologia vegetal
Resumo
Water deficit is one of the main factors limiting agricultural growth and productivity, especially in semi-arid regions, where water availability is often irregular and insufficient to meet crop demands. Understanding how different cultivars respond to water stress is crucial for developing management strategies that maximize yield under adverse conditions. This study evaluated the effects of water stress on vegetative growth and biomass accumulation in different sesame cultivars, a crop of significant economic and nutritional importance due to its oil-rich seeds. The experiment was conducted in a greenhouse at UFERSA, Mossoró–RN, using a randomized block design in a 3 × 4 factorial scheme, with three irrigation levels (100%, 70%, and 40% of reference evapotranspiration – ETc) and four cultivars (BRS Seda, BRS Anahí, BRS Morena, and CNPA G4). Morphophysiological variables were assessed, including plant height, stem diameter, leaf number, and dry biomass of leaves, stems, and roots, providing insights into how each cultivar allocates resources under varying water availability.
The CNPA G4 cultivar stood out for stem dry biomass accumulation, showing values 32.7% higher than BRS Seda, 26.4% higher than BRS Morena, and 66.0% higher than BRS Anahí. Additionally, it exhibited a higher number of leaves and larger stem diameter, suggesting a strong investment in aerial growth, which could contribute to greater photosynthetic capacity and overall plant vigor. In contrast, BRS Seda showed higher root dry biomass, surpassing Morena by 55.6%, Anahí by 29.1%, and CNPA G4 by 9.1%, indicating a strategy focused on enhancing root development to optimize water and nutrient uptake. Water deficit significantly reduced plant growth and biomass accumulation across all cultivars. Plants under full irrigation (100% ETc) reached 26% greater height compared to those at 40% ETc, with 51% more stem dry biomass and 46.7% more root dry biomass, demonstrating the critical role of sufficient water supply in sesame development. These findings emphasize the importance of precise irrigation management to ensure optimal growth and productivity. Furthermore, the results highlight the distinct adaptive strategies of sesame cultivars under water stress: CNPA G4 excels in stem biomass accumulation, while BRS Seda invests in root development, which may inform future breeding programs and cultivar selection for semi-arid environments.