Bondi Junction NSW, Australia
Fact Sheets
Citrus canker (091)
Pacific Pests, Pathogens and Weeds
Pacific Pests, Pathogens and Weeds


  • Widespread distribution. On citrus including grapefruit, kumquat, lemon, lime, mandarin, orange, pomelo and tangerine, as well as other genera in the citrus family. An important disease.
  • Bacterial spots on both sides of leaves and fruit causing them to fall early. Fruit unsightly. Spots up to 10 mm, with haloes on the leaves. Cankers cause twig dieback.
  • Worse on grapefruit, lemon, lime and sweet orange.
  • Spreads in wind-driven rain, water splash, and nursery plants. Enters through natural openings, wounds (e.g., leafminers). Survival is in leaf litter, and weeds.
  • Cultural control: ensure nursery is canker-free; keep out of orchard when leaves wet; plant windbreaks around and between rows; Valencia orange and mandarin tolerant.
  • Chemical control: 2-3 copper fungicide sprays 3 weeks apart, beginning when fruits are about 5 mm diameter.

No responses yet...