RRDI_RiceDiseases_Diagnose_FieldSymptomsAndPatterns

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RICE IN SRI LANKA - Rice Diseases

Field symptoms and patterns

Distribution of affected plants in a field could be studied to understand whether the problem is developing a pattern.

Once the field has been sufficiently scouted and analyzed, few affected plants should be removed entirely (with all parts intact) and examined in comparison with the healthy plants from the same fields so that useful clues may be found.

Disorders and not diseases

Some symptoms could be due to various disorders, and not due to diseases.
E.g. plants that are in the border of the field show a normal and healthy appearance, and plants in the center show yellowing and poor growth could be due to lack of plant nutrients

Environmental conditions

Environmental conditions such as low or high temperature, water availability (deficiency or stagnated water), or  field practices such as herbicide or pesticide application (toxicities), biological attacks, or a combination of few /all above might provide a basis for an observed symptom.

Poor root growth

Plants might show a stunted growth, which is an  indication of poor root growth resulted from compacted shallow plough pan, root rot, root injury from nematode feeding, or a nutrient deficiency.

Discoloration and missing plants

Discoloration or missing plants in pockets might be an indication of an increased soil nematode population,  root rots, or specific soil related problems.

Disorders and not diseases

Some symptoms could be due to various disorders, and not due to diseases.
E.g. plants that are in the border of the field show a normal and healthy appearance, and plants in the center show yellowing and poor growth could be due to lack of plant nutrients

Environmental conditions

Environmental conditions such as low or high temperature, water availability (deficiency or stagnated water), or  field practices such as herbicide or pesticide application (toxicities), biological attacks, or a combination of few /all above might provide a basis for an observed symptom.

Poor root growth

Plants might show a stunted growth, which is an  indication of poor root growth resulted from compacted shallow plough pan, root rot, root injury from nematode feeding, or a nutrient deficiency.

Discoloration and missing plants

Discoloration or missing plants in pockets might be an indication of an increased soil nematode population,  root rots, or specific soil related problems.