Which nutrient deficiency is typically indicated by the purple discoloration of leaves?

Explanation

Purple coloration in leaves is a classic symptom of phosphorus deficiency in plants. This occurs because phosphorus is essential for energy transfer and other metabolic processes, and its lack leads to accumulation of anthocyanin pigments, which cause the purpling effect. Deficiencies of iron, potassium, or nitrogen usually result in different symptoms such as chlorosis or necrosis.