Integrating plant density management with chitosan and amino acid -based biostimulant represents a promising strategy to enhance crop performance under water-limited conditions. In this study, we evaluated the combined effects of plant density, foliar chitosan, and amino acid-based biostimulant on sunflower growth, morphophysiological traits, and yield under water deficit conditions. A field experiment was conducted using a split-split-plot design with four replicates, where plant density (25, 000 and 50, 000 plants ha-1) was assigned to the main plots, chitosan application (0 and 200 mg L-1) to the subplots, and amino acid-based biostimulant (0 and 1.2 mL L-1 as VIUSID® Agro) to the sub-subplots. Our results indicated that increasing plant density from 25, 000 to 50, 000 plants ha-1 significantly enhanced crop performance under water-deficit conditions, improving growth indices and seed yield. The combined treatment D50, 000Q200A1.2 (50, 000 plants ha-1 + 200 mg L-1 chitosan + 1.2 mL L-1 amino acids) produced the strongest responses and the highest seed yield when compared with D25, 000Q0A0 (25, 000 plants ha-1 without chitosan or amino acid application). Specifically, D50, 000Q200A1.2 increased plant height by 66%-70%, leaf area by 56%-71%, leaf area index by 111%-127%, dry biomass by 92%-169%, and relative chlorophyll content by 39%-47%, indicating enhanced photosynthetic capacity under water-deficit conditions. These improvements translated into substantial yield gains, with seed yield increasing by up to 3.1-fold relative to the D25, 000Q0A0 treatment. Overall, these findings demonstrated that the synergistic integration of optimized plant density with foliar chitosan and amino acid biostimulants enhances sunflower growth, physiological performance, and productivity under water-deficit conditions, providing a robust and sustainable strategy for improving crop resilience and yield stability.
Citation: Alexander Calero Hurtado, Felipe Augusto Queiroz de Almeida, Daniel Gonçalves da Silva Pinheiro, José Vitor Botter Fasoli, Thainá Pereira da Silva Cabral, Bruna Wilke Rampassi, Kolima Peña Calzada. The combined effects of plant density, chitosan, and amino acids enhance the sunflower growth and yield under water deficit conditions[J]. AIMS Agriculture and Food, 2026, 11(2): 399-421. doi: 10.3934/agrfood.2026021
Integrating plant density management with chitosan and amino acid -based biostimulant represents a promising strategy to enhance crop performance under water-limited conditions. In this study, we evaluated the combined effects of plant density, foliar chitosan, and amino acid-based biostimulant on sunflower growth, morphophysiological traits, and yield under water deficit conditions. A field experiment was conducted using a split-split-plot design with four replicates, where plant density (25, 000 and 50, 000 plants ha-1) was assigned to the main plots, chitosan application (0 and 200 mg L-1) to the subplots, and amino acid-based biostimulant (0 and 1.2 mL L-1 as VIUSID® Agro) to the sub-subplots. Our results indicated that increasing plant density from 25, 000 to 50, 000 plants ha-1 significantly enhanced crop performance under water-deficit conditions, improving growth indices and seed yield. The combined treatment D50, 000Q200A1.2 (50, 000 plants ha-1 + 200 mg L-1 chitosan + 1.2 mL L-1 amino acids) produced the strongest responses and the highest seed yield when compared with D25, 000Q0A0 (25, 000 plants ha-1 without chitosan or amino acid application). Specifically, D50, 000Q200A1.2 increased plant height by 66%-70%, leaf area by 56%-71%, leaf area index by 111%-127%, dry biomass by 92%-169%, and relative chlorophyll content by 39%-47%, indicating enhanced photosynthetic capacity under water-deficit conditions. These improvements translated into substantial yield gains, with seed yield increasing by up to 3.1-fold relative to the D25, 000Q0A0 treatment. Overall, these findings demonstrated that the synergistic integration of optimized plant density with foliar chitosan and amino acid biostimulants enhances sunflower growth, physiological performance, and productivity under water-deficit conditions, providing a robust and sustainable strategy for improving crop resilience and yield stability.
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Figures(8) / Tables(1)
Alexander Calero Hurtado, Felipe Augusto Queiroz de Almeida, Daniel Gonçalves da Silva Pinheiro, José Vitor Botter Fasoli, Thainá Pereira da Silva Cabral, Bruna Wilke Rampassi, Kolima Peña Calzada. The combined effects of plant density, chitosan, and amino acids enhance the sunflower growth and yield under water deficit conditions[J]. AIMS Agriculture and Food, 2026, 11(2): 399-421. doi: 10.3934/agrfood.2026021
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