Potassium deficiency (K)Potassium deficiency symptoms are mainly discernible on the plant’s lower, older leaves. They are recognisable as pale-green/yellow discolorations on leaf-blades, between the leaf veins, with necrotic edges. This necrosis shows a tendency to spread toward the interior of the leaf, which will then begin to curl downward.
Treatment: Once symptoms have occurred, the treatment of potassium deficiency is difficult. It is therefore advisable to prevent damages by ensuring a balanced supply of potassium to the soil.