Which nutrient promotes growth of roots?

• A. Nitrogen
• B. Potassium
• C. Vitamins
• D. Phosphorus

Answer: (D)

Phosphorus promotes root growth because it is essential for energy transfer and cellular development that drive root formation and expansion. It powers ATP and nucleic acid synthesis, providing the energy and genetic material needed for roots to elongate and branch into the soil. A strong root system lets the plant access water and nutrients more effectively, especially during early growth. If phosphorus is low, roots tend to be stunted and poorly developed even when other nutrients are adequate. Nitrogen mainly fuels leafy, vegetative growth and chlorophyll production; potassium supports overall vigor and water regulation but is not the primary driver of root formation. Vitamins aren’t the key nutrients for root development in plants. So, phosphorus is the nutrient that best promotes root growth.