|
|
External Symptoms
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Internal Symptoms
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Spread in Storage
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Main Source
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ROTS
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Bacterial Soft Rot
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slimy, tan spots around wounds or at stem end
|
slimy, soft rot with dark borders
|
yes
|
vine, soil
|
Leak
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dark, large areas; smell; papery shell
|
liquidized, cavities rancid smell
|
no
|
soil
|
Pink Rot
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dark areas near stem end, around eyes and pores
|
pink area afer cutting; slight odor
|
yes
|
soil
|
Dry Rot
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dry decay around wounds fungal growth possibly seen
|
dry cavity from wounds; possible ring discoloration
|
no
|
vine, soil
|
NON-Rotting
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Black Dot
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shiny, brownish areas, reddish on attached stolon
|
none
|
yes
|
seed, debris
|
Silver Scurf
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shiny, silvery areas
|
none
|
yes
|
seed
|
Common Scab
|
rough, round surface areas to brown pits
|
pits extend into tuber
|
no
|
soil, seed?
|
Early Blight
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brownish-blac k, irregular sunken areas
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shallow, dry and brown below sunken areas
|
yes
|
lifting
|
Black Pit
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narrow, deep, black pits
|
pits extend into tuber
|
?
|
?
|
Late Blight
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brown areas turning black and sinking (depressions)
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reddish brown below discolored areas
|
Z
|
leaching
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Black Scurf
|
black, hard, small spots
|
none
|
no
|
soil
|
Early Dying
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none; pink eye may occur
|
vascular discoloration
|
no
|
vine, soil
|
|