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: Aster yellows
HOST: Barley
Infection by this phytoplasm causes twisted awns and sterile florets.
Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Aster yellows
HOST: Barley
Small necrotic spots on lower leaves and red coalescing streaks on upper leaves.
Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Infected leaf with olive green, puffy appearance.
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: G. Taniguchi
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Advanced stage of heart rot. Note puffy appearance of discolored midportions of central heart leaves.
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: C. V. Subere
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Dark, necrotic, decayed area at bases of central heart leaves. Advanced stage is characterized by an olive green leaf color and puffy appearance of midportions of leaves.
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: K. Rohrbach
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Diseased plant with reddening of leaves, a symptom of the disease.
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: G. Taniguchi
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Diseased pineapple (right) has olive green color. Healthy fruit (left).
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: K. Rohrbach
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple
Diseased ripe fruit with external discoloration.
Bacterial heart rot and fruit collapse | Pineapple
DISEASE: Bacterial heart rot and fruit collapse
HOST: Pineapple (Ananas comosus)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: C. V. Subere