Micro-elements are quite often referred to as the “trace” elements since they are used in such minute quantities in the nutrient solution. Micro-elements tend to be catalysts rather than fixed in any structure. They tend to be mobile in the plant and the difference between toxic levels and deficient levels is quite narrow. Although micro-elements are found in low concentrations in plants, they play an important role in plant metabolism.

Iron (Fe):

• Oxygen carrier and enzyme catalyst
• Required during chlorophyll production and protein synthesis
• Plays a role in respiration; Co-factor in several enzymes
• Most immobile nutrient in plants.

Boron (B):

• Plays a role in meristimatic tissue of plants
• Immobile element in plants
• Enhances the uptake cations and limits the uptake of anions
• Enhances the uptake of Ca especially
• Influences carbohydrate and nitrogen metabolisms.

Manganese (Mn):

• Mainly a catalyst in various processes
• Plays a role in carbohydrate metabolism and chlorophyll formation
• Helps with root aeration
• Accelerates plant growth

Zinc (Zn):

• Activity is linked to amount of light available
• It is a regulating catalyst and enzyme actuator
• Forms part of the growth hormone indoleacetic acid
• Helps with the removal of carbon dioxide
• Plays a critical role in the oxidation reduction processes in the cell

Copper (Cu):

• Plays an important part in plant metabolism
• Help with the synthesis of chlorophyll
• Helps with the activity of enzymes
• Is available as en electron carrier
• Plays an important part in the disease resistance of plants

Molybdenum (Mo)

• Has a close relationship with nitrogen
• Plays a part in carbohydrate processes
• Involved as an enzyme co-coordinating catalyst
• Mo is involved in converting nitrates to ammonia in the plant