It is found in very low amounts in the soil and the needs of plants are also very low. Plants can absorb Molybdenum from the soil and leaves as Molybdate ion (Mo-2). Its deficiency is seen in soils with a pH lower than 5.5.

     Especially cauliflower and cabbage have a high molybdenum requirement. Lettuce, spinach, beet, and citrus species are also sensitive plants. Molybdenum prevents nitrate accumulation in the plant body. It enables the metabolism of nitrogen. It is effective in protein formation. Molybdenum is effective on vitamin C synthesis. In its deficiency, the vitamin C content of plants decreases.

  Since there is no nitrate assimilation in molybdenum deficiency, nitrate accumulates in plants and symptoms similar to nitrogen deficiency occur. Yellowish spots appear between the veins of old leaves. Unlike nitrogen deficiency, leaf edges turn yellow and dry quickly. Unbalanced growth is seen in the leaf.

Functions of Molybdenum in Plants

· It prevents the accumulation of nitrate by reducing nitrate to ammonium through its enzyme activity. It takes part in nitrogen fixation.

· It helps the formation of Vitamin C (Ascorbic Acid).

· It is effective on phosphorus metabolism. In its deficiency, organic phosphorus turns into inorganic phosphorus.

Molybdenum Deficiency Symptoms

· Deficiency symptoms are similar to nitrogen and show themselves primarily on older leaves.

· The only difference from nitrogen deficiency is that the leaf edges dry out and curl immediately, as does the yellowing between the veins.

· Leaf blade width decreases. Small, different shaped leaves are formed.

· The flowers are pale in color, the plant is small and has a parched appearance. Cauliflower cannot form heads.

· Diseases affect the plant more quickly.

Conditions That Reduce Molybdenum Uptake

· Acidic soils with a pH lower than 5.5.

· Soils with insufficient molybdenum content.

· Soils with low nitrogen content.

· Soils containing excess copper, iron and aluminum.