SHEATH ROT
SYMPTOMS
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Discoloration in the flag leaf sheath.
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Rotting occurs on the leaf sheath that encloses the young panicles.
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irregular spots or lesions, with dark reddish brown margins and gray center.
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discoloration in the sheath.
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lesions enlarge and often coalesce and may cover the entire leaf sheath.
Although sheath rot can be observed in the field as single disease on rice sheath, more often it has become part of a complex of grain and leaf sheath discoloration commonly observed on wet season rice.
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Check for lesions.
The typical sheath rot lesion starts at the uppermost leaf sheath enclosing the young panicles. It appears oblong or as irregular spot with dark reddish, brown margins, and gray center or brownish gray throughout.
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Check for spots.
Usually several spots are observed and these spots enlarge and combine or grow together and can cover most of the leaf sheath. Panicles remain within the sheath or may partially emerge. Affected leaf sheaths may have abundant whitish powdery fungal growth (mycelium) visible on the outer surface. Panicles that have not emerged rot and the florets turn red-brown to dark brown.
