Bacterial Blight

Bacterial Blight Information

By Josie Borlongan, Garden Guides Contributor

About Bacterial Blight

Bacterial blight is caused by bacteria known as Xanthomonas campestris. It is spread by rain splash and insects. Most plants are susceptible to bacterial blights during warm, wet weather from stem injuries from natural causes or pruning lush vegetative growth resulting from excessive nitrogen fertilizer. Bacterial blight is highly prevalent during spring time.

Prevention and Control

Cut off infected parts or remove infected plants and discard or compost. Also avoid handling plants during wet weather so as not to transfer the infection to other plants.

Affected Plants

Different types of flowers and fruit trees


Bacterial blight is starts with an appearance of a small, green spots on the affected areas of the leaf, which then appears water soaked. In time, these lesions then appear as dry dead spots as they become larger. In the latter part of infection, the lesions become more elongated, extending to the full size of the leaf. Bacterial blight can cause discoloration of the leaves and rapid deterioration of plant tissues thereby killing the plants.

Natural Insecticides

Copper is a natural mineral that can be applied as dust or foliar spray. It is the strongest type of organic bactericide and fungicide available.

Other Methods of Control

* Garden Cleanup: Remove plants and debris which are infected by bacterial blight. Gather them and throw them away or compost. Infected crop residue may also be buried to prevent the spread.
* Crop Rotation: Rotate the plantings every 2 years. The severity and incidence of bacterial blight may be reduced by rotating to non-grain crops. Use disease-free seeds next time you plant. There are no resistant cultivars known.
* Clean Tools: Avoid using tools on healthy plants that were used on infected plants. Sterilize tools in warm water or by rubbing disinfectant before using.

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