🦠 Symptoms Caused by

Nematode symptoms are diverse and often confused with nutrient or water stress, so symptom pattern recognition is a key diagnostic skill. This lesson classifies major symptom groups seen in crops.

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Symptom Classification Framework

Nematode disease symptoms are commonly grouped into above-ground and below-ground manifestations. Both should be assessed together for more reliable diagnosis.

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Above-Ground Symptoms

Above-ground effects include chlorosis, patchy stunting, poor tillering, wilting under mild stress, and characteristic foliar distortions in some crop-nematode combinations.

Specific examples include white tip-like symptoms in rice and crop-specific canopy decline patterns.

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Below-Ground Symptoms

Root systems may show galls, lesions, necrosis, reduced branching, stubby roots, and poor feeder-root development. These changes reduce water and nutrient uptake efficiency.

Root symptoms are often the most direct evidence of nematode involvement.

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Differential Diagnosis Considerations

Because many symptoms overlap with other constraints, confirmatory diagnosis should combine field signs, root observation, and nematode extraction where possible.

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Summary Cheat Sheet

Topic	Key Point
Main categories	Above-ground and below-ground symptoms
Above-ground signs	Stunting, chlorosis, wilting, poor vigor
Below-ground signs	Galls, lesions, root reduction, stubby roots
Diagnostic challenge	Strong overlap with abiotic disorders
Best approach	Symptom + root evidence + nematode confirmation

Exam focus: symptom categories and hallmark root symptoms linked to major nematode groups.

References

1 source • [1]

[1]

Symptomatology notes for plant parasitic nematodes (PATH172)

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