Potassium deficiency symptoms in banana are quickly evident when it is not continuously applied under intensive banana cultivation. One of classic symptoms of K deficiency is rapid yellowing of oldest leaves, which then turn orange and dry-up; leaves may become tattered and fold downward; leaves are crumpled in appearance Splits develop parallel to the secondary veins and the lamina folds downwards, while the midrib bends and fractures, leaving the distal half of the leaf hanging.