DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Petal blight
HOST: Orchid
Flower petals of Vanda orchid with necrotic spots.
Petal blight | Orchid
DISEASE: Petal blight
HOST: Orchid (Vanda sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: A. Alvarez
DISEASE: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues near peduncle end of fruits. Pigmentation and yellow translucence of papaya flesh are more evident of fruit on right.
Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues.
Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Another view of purple discoloration at peduncle end. Bacteria are found in vascular tissues and latex ducts.
Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: K. Nishijima
DISEASE: Purple stain
HOST: Papaya
Cross section of fruit exhibiting purplish discoloration in latex ducts.
Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson, A. Alvarez