Leaf pigments in cauliflower cultivated with different water conditions and silicon applications

Environmental factors and crop management can influence the characteristics of plant morphology and physiology, altering photosynthetic efficiency and mass accumulation. The study aimed to analyze the contents of leaf pigments in cauliflower cultivated under different conditions of water availability and silicon (Si) applications. The experiment was carried out in a protected environment in the city of Maringá-PR. A randomized block design, in a 3x4 factorial scheme, with three replacement conditions [40, 70 and 100% of crop evapotranspiration (ETc)] and four Si doses (0, 50, 100 and 150 kg ha-1), with four repetitions. The cauliflower cultivation, cultivar Sharon, was carried out in dystroferric RED NITOSOL. Daily evapotranspiration was determined with a constant level water table lysimeter and water replacement was performed with drip irrigation. Si was applied in split doses in three applications (initial, intermediate and final phases). At flowering, leaf tissue from the upper third of the plant was collected, with pigment extraction performed with pure acetone and determination in a spectrophotometer. At harvest, the leaf area of ​​the plants was determined. Data were subjected to analysis of variance and regression analysis. Cauliflower crop under water-deficient reduces leaf area development and alters chloroplast pigments dynamics. Silicon use in the soil increases leaf development, chlorophyll a and b contents, and reduces carotenoids concentration. Under water stress conditions, silicon addition to the soil improves cauliflower performance.