How to Manage Pests

UC Pest Management Guidelines

SYMPTOMS

Bacterial blight symptoms appear as brown, sunken lesions on the petals that enclose the floral buds. During bud expansion, the petals exhibit a yellow-orange discoloration that later becomes necrotic. The buds fail to mature and abscise. Leaf spotting occurs only after summer rains or when overhead irrigation is used. The leaf spot phase occurs along the leaf margins and begins as small, yellow halos 0.04 to 0.08 inch (1 to 2 mm), the center of which becomes necrotic. Later the spots enlarge and coalesce to form large irregular patches of necrotic tissue.

COMMENTS ON THE DISEASE

Pseudomonas viridiflava and Pseudomonas syringae are widespread plant pathogens that exist on the leaf surfaces of many fruit and vegetable crops. They gain entry into a plant through injured tissues, or when the plant has been predisposed to disease by conditions such as chilling injury or rainfall that favor growth of the bacteria.

MANAGEMENT

Currently no cultural practices or chemical controls are recommended for control of this disease.

PUBLICATION

UC IPM Pest Management Guidelines: Kiwifruit
UC ANR Publication 3449
Diseases
J. E. Adaskaveg, Plant Pathology, UC Riverside
T. J. Michailides, Plant Pathology, Kearney Agricutural Center, Parlier
W. D. Gubler, Plant Pathology, UC Davis
Acknowledgment for contributions to the disease section:
C. Arredondo, Plant Pathology student, UC Davis
K. Conn, Plant Pathology, UC Davis

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