Molybdenum Deficiency

Molybdenum is needed by the plant in the synthesis and activation of nitrate reductase, an enzyme which reduces nitrate to ammonium in the plant. It is also required for symbiotic fixation of N within legume root nodules and for the conversion of inorganic P to organic forms in the plant. Unlike other micronutrients, Mo availability in the soil increases with higher soil pH. Sandy soils are more likely to be deficient in Mo.
Heavy P fertilization can increase Mo uptake by plants from the soil, while S fertilization reduces Mo uptake and can induce a Mo deficiency.

Symptom Description — Molybdenum deficiency symptoms frequently resemble N deficiency. Older and middle leaves become chlorotic first, and in some instances, leaf margins are rolled and growth and flower formation is restricted.

Molybdenum Deficiency in Video