The symptoms of phosphorus deficiency start on older leaves. The leaves show a darker, blue-green color, and yellow chlorotic zones develop in the intercostal areas from the leaf margin. Later, these zones coalesce and become necrotic with a light brown color.
Phosphorus deficiency Excess nitrogen fertilization also leads to a blue-green color of the leaves. Manganese deficiency also causes marginal necrosis, but these have a darker color.
Slow growth with thin and woody stems; petioles break easily.