Effect of Methylobacterium on the yield and quality of cauliflower (Brassica oleracea)
Abstract The soil used is sandy in texture, low in nutrients, and low in organic matter, and therefore has low cation exchange capacity. Therefore, the objective was to evaluate the effectiveness of improving their physicochemical and biological properties by inoculating the roots with a solution of Methylobacterium and liquid compost in cauliflower cultivation, as well as integrating a treatment through an automated drip irrigation system. This biostimulant, biofertilizer, and biocontrol agent solution was used, which has applications in agriculture to improve soil health and crop productivity. The experiment was set up under a completely randomized block design with four treatments (T0, T1, T2, and T3), corresponding to doses of 0, 250, 333, and 400 mL per 200 L of water, respectively. The results indicated that treatment T3 significantly optimized the plant's physiological response to salt stress, increasing both its antioxidant capacity and chlorophyll α concentration. Likewise, physical characterization revealed significant differences in the morphological parameters of cauliflower, suggesting greater metabolic resistance and improved nutritional quality. Finally, ultrastructural analysis of the epidermis and stomata using microscopy showed that, while the control treatment (T0) had a collapsed surface, treatment T3 showed a functional and turgid ultrastructure. This demonstrates that the inoculation applied mitigates the phytotoxic impact of the substrate and optimizes the metabolic potential of the crop.