Trace Elements Deficiency

The macro nutrients that plants need in relatively large quantities are nitrogen (N), sulphur (S), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). But plants also need trace elements in small quantities for healthy growth. Trace elements include; iron (Fe), manganese (Mn), boron (B), copper (Cu), zinc (Zn), molybdenum (Mo) and humic acids.

If any of these are not available to the plant it may suffer characteristic symptoms.

• Iron deficiency - causes yellowing leaves due to low levels of chlorophyll. Leaf yellowing first appears on the younger upper leaves in between veins. Severe iron deficiency may cause leaves to turn completely yellow or almost white, and then brown as leaves die.
• Manganese deficiency - cause yellowing of leaves between veins. In very severe manganese cases, brown necrotic spots appear on leaves, resulting in leaves falling off. Manganese deficiency is often a sign of high pH soil or sandy soil with low levels of organic matter.
• Boron deficiency - causes stunted appearance, brittle, discoloured leaves and loss of fruiting bodies. It affects new growth and upper parts of plants first.
• Copper deficiency - causes die-back of stems and twigs, yellowing of leaves, stunted growth and pale green leaves that wither easily.
• Zinc deficiency- causes stunted growth, short stem length between leaves and branches and a decrease in leaf size. Delayed maturity also is a symptom of zinc-deficient plants
• Molybdenum deficiency - causes stunting and failure of leaves to develop a healthy dark green colour. The leaves of affected plants show a pale green or yellowish green colour between the veins and along the edges. In advanced stages, the leaf tissue at the margins of the leaves dies. The older leaves are the more severely affected. These symptoms are similar to magnesium deficiency.