For normal growth and to complete their lifecycle, your crops require 16 nutrients. Of them, six are micronutrients and they are an essential part of nutrition. Termed ‘micro’ due to the small amounts required by the plant, their lack often play a ‘major’ role and result in visible crop loss.
The six micronutrients are:
Function: Boron is an essential element in plant nutrition. It is essential for root tip, pollen tube and shoot growth and the synthesis of DNA and RNA. It improves seed set under stressful conditions.
Symptoms of Deficiency: Leaf blades may be distorted and stems may become brittle and crack e.g. “stem crack” in celery. Shorter internodal length, retarded growth or necrosis of the terminal buds and youngest leaves. Reduction or failure to seed and fruit. Malformation of fruit.
Function: Copper is an essential nutrient required for the functioning of a large number of enzymes involved in the growth and reproduction of plants. It is required for the synthesis and functioning of chlorophyll, is involved in the plant hormone system and acts as a catalyst for the plant growth regulator, auxin.
Symptoms of Deficiency: Young leaves become dark green,twisted and deformed. Necrotic spots may appear. In grains and grasses,seed production is reduced and seed heads may be white and empty.
Function: Iron is an essential element required for the synthesis of chlorophyll. It is involved in the activation of many enzymes used in photosynthesis and respiration. Iron is relatively immobile and is generally in short supply in alkaline soils. Iron acts as an oxygen carrier in the nodules of legume roots.
Symptoms of Deficiency: Pale green leaves (chlorosis) with sharp distinction between green veins and yellow interveinal tissues.
Function: Manganese is an essential nutrient for the growth of plants. It enhances root growth, disease resistance and the development of fruit. It is required for the synthesis of chlorophyll and assimilation of nitrate. It is involved in the activation of many enzymes involved in photosynthesis and respiration.
Symptoms of Deficiency: Symptoms vary with species; in cereals – grey – white spots, flecks and stripes may appear in the interveinal areas. In legumes, interveinal chlorosis of young and middle aged leaves and tissue may rapidly become necrotic. Seed disorders e.g. “split seed” or “marsh spot” may develop.
Function: Molybdenum is required for protein synthesis.It enhances both photosynthesis in plants and nitrogen fixation in legumes. It optimises plant growth.
Symptoms of Deficiency: Reduced and irregular leaf blade formation, interveinal mottling and chlorosis around the edges of older leaves. Necrotic spots at leaf tips and edges, smaller root nodules coloured white or green (not pink),growth inhibition in legumes. Stunted plant growth and general yellowing, marginal scorching and cupping or rolling of leaves.
Function: Zinc is an essential nutrient required for the functioning of a large number of enzymes involved in the growth and reproduction of plants. It is required for the synthesis and functioning of chlorophyll, is involved in the plant hormone system and as a catalyst for the plant growth regulator, auxin. It plays
Symptoms of Deficiency: Deficiency symptoms first appear on the younger leaves. Shortened internodes with excessive branching (resetting) of small, dark green deformed leaves are also an indicator. In cereals and grasses – chlorotic bands (yellow, red) may appear either across or within the veins. Stunted growth and necrosis of older leaves.