Diagnosing nutrient deficiencyA systematic approach is required in diagnosing nutrient deficiency based on visual symptoms for the following reasons:

Nutrient-deficient rice plants

1 Nutrient deficiency symptoms are often misdiagnosed as disease caused by pathogens.

2 Diagnosis may be complicated when:

T• here is more than one nutrient deficiencyThere is simultaneous deficiency of one nutrient and simultaneous toxicity of • another nutrientThere are damages by pests, disease symptoms, or mechanical injuries including • spray damage

3 Nutritional disorders including nutrient deficiencies always have a typical symmetric pattern.

Leaves of the same or similar position or physiological age on a plant show nearly • identical patterns of symptomsThere is a marked graduation in the severity of the symptoms from old to young • leaves