Tuber Wet Rot

Harvest conditions influence the development of wet rots in storage. Storage conditions also influence the spread of wet rots through the storage bin. There are no varieties know to be resistant or tolerant to wet rots. The key factors used to avoid wet rots and their spread are COOLNESS, DRYNESS, and AERATION.

The primary rots affected are:

Leak (Pythium leak, shell rot) = Pythium spp.
Pink Rot = Phytophthora erythroseptica
Soft Rot (bacterial soft rot, blackleg) = Erwinia carotovora

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