Question

purple discolouration along the edges of leaf is due to

Answer 1

When you notice a plant with purple leaves rather than the normal green color, it is most likely due to a phosphorus deficiency. All plants need phosphorus (P) in order to create energy, sugars and nucleic acids. Young plants are more likely to display signs of phosphorus deficiency than older plants

Answer 2

it occurs because of a phosphorus deficiency.