Manganese deficiency occurs in a wide range of crops with onions, beetroot, parsnip, cabbage, cauliflower, tomato and pumpkin the most susceptible
Manganese (Mn) is an important plant micronutrient and is required by plants in the second greatest quantity compared to iron. Like any other element, it can have a limiting factor on plant growth if it is deficient in plant tissue.
Function - Manganese is used in plants as a major contributor to various biological systems including photosynthesis, respiration, and nitrogen assimilation. Manganese is also involved in pollen germination, pollen tube growth, root cell elongation and resistance to root pathogens.
Symptoms of deficiency -
- In general, affected crops are pale green and growth is reduced.
- Specific symptoms may first appear on the youngest or oldest leaves and vary from species to species.
- The most common symptom is for leaves to turn pale green between the veins, with normal coloured areas next to the veins.
- As the deficiency progresses, the area between the veins becomes paler, enlarges and may brown and die.
- In cabbage, the interveinal chlorosis symptom is replaced by a general mottled yellowing of the leaves.
- Beetroot shows triangular or spear-shaped leaves with the edges curled forward, as well as yellow mottling with small dead patches which give the leaf a typical speckled appearance.
- In onions and sweetcorn, the interveinal chlorosis appears as yellow stripes on the leaves.
- In tomatoes, the veins remain green, while the tissue between the veins becomes increasingly yellow as the deficiency becomes worse. This causes a net-like pattern to appear on the leaves.
Liquid Manganese 25%Mn
Manganese is applied mixed in water and applied on the crop, once to twice during growing season
1-3L/ha in 120-300 l of water.