Role of Manganese in Tomato Production

Manganese is required for chlorophyll formation and oxide-reduction reactions in cells. It is also involved in the synthesis of ascorbic acid (Vitamin C).

Manganese effect at growth stages

Stage Manganese effect
Establishment Ensure good shoot growth
Vegetative Growth Ensure growth is not limiting
See more on Tomato Growth Stages.

General guidelines for Manganese application

While rarely seen, transient deficiencies can occur during wet seasons or in sandy or peaty soils of a high pH. Manganese is not very mobile in the plant and deficiencies are best prevented by using foliar sprays. Temporary Mn deficiency is known as ‘growth mottle’ and is seen during flushes of rapid plant growth. Manganese toxicity can occur in tomato crops grown on low pH soils or where excessive applications of acidifying fertilizers are applied. The stems and petioles, especially in the nodal areas, may show necrotic lesions.

Manganese deficiencies in Tomato

Tomatoes are very susceptible to manganese deficiency. Interveinal areas develop yellowish gold spots giving the leaf a speckled appearance. All veins, including the very small ones, and a small frame around the veins, remain green. Petioles and the stems can develop similar Symptoms. Few flowers or fruit will develop if the deficiency is severe.

See more about manganese and other nutrients deficiencies in tomatoes on Tomato Crop Nutrition.