Nutritional disorders in trees

Symptoms of nutrient disorders usually appear as mirror-image patterns on either side of the leaf mid-vein. (Phosphorus disorder symptoms are the exception.)

Symptoms of fungal diseases or pests appear as irregular patterns and distributions.

Use this key to determine some common nutritional disorders in plantation trees. Work through the key from left to right to identify the nutrient disorder in your tree.

Affected area General symptoms Deficiency Symptoms
Symptoms appear first of more prevalent on mature leaves Leaves discoloured evenly Nitrogen (N) Leaves pale green to yellow
Phosphorus (P) Leaves green with reddish blotches or uniformly purple to red
Leaves discoloured in patterns Magnesium (Mg) Distinct interveinal chlorosis (discolouration), often bright yellow
Potassium (K) Leaves with marginal burns often expanding to interveinal areas
Symptoms appear first or more prevalent on expanding leaves Reduced growth or dieback in the shoot apex Boron (B) Enlarged nodal regions; slow growth; sometimes apical death; proliferation of lateral shoots; interveinal crinkling in younger leaves; corky abaxial veins or malformed margins
Calcium (Ca) Nodes normal; apical shoot death; leaves buckled due to reduced growth of margins; leaf expansion often stunted
No dieback in the shoot apex - leave normal size Copper (Cu) 'S' shaped stem growth, leaved with irregular or undulate margins, some interveinal chlorosis
Sulfur (S) Leaves pale green to yellow
Iron (Fe) Interveinal chlorosis with sharp borders to green veins
Manganese (Mn) Leaves with marginal or mottled chlorosis; small necrotic bleached or brown spots may appear
No dieback in the shoot apex - leave small and crowded Zinc (Zn) Developing interveinal chlorosis with hazy borders to green veins

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