Molybdenum deficiency is characterized by which symptom?

• A. New leaf chlorosis
• B. Pale new growth
• C. Interveinal chlorosis on young leaves
• D. Leaf curling

Answer: (B)

Molybdenum is needed for nitrate reduction and assimilation into amino acids. When Mo is deficient, plants can’t effectively convert nitrate into usable forms, which hampers growth and chlorophyll development, especially in new, actively growing tissue. That’s why the new leaves become pale—the plant isn’t producing as much chlorophyll in the developing growth where Mo demand is highest. Older leaves may stay greener for a while, but the latest growth shows the deficiency first. Other patterns, like interveinal chlorosis on young leaves, are more typical of iron or zinc deficiencies, and leaf curling is a nonspecific stress symptom. So, pale new growth best captures the characteristic effect of molybdenum deficiency.