Polysaccharides combined to copper and magnesium improve tomato growth, yield, anti-oxidant and plant defense enzymes

•Foliar sprays of polysaccharides in association with copper and magnesium significantly increased tomato growth and yield.•The association of polysaccharides with copper improved the nutrient content of tomato leaves in comparison with the applications of polysaccharides alone.•Applications increased the concentration of antioxidant enzymes and the β 1,3 glucanase enzyme, while reducing the severity of powdery mildew in tomato leaves.