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Pests and Diseases
Noni shot hole
shot hole
Noticeable ?shot hole? appearance and yellowing of noni leaf with shot hole disease.
Tiny, pinpoint maroon-colored flecks
Tiny, pinpoint maroon-colored flecks on noni bracts.
shot hole lesions
Tiny maroon-colored flecks and shot hole lesions scattered over the surface of a diseased noni leaf. Chlorotic (yellow) halos are visible around lesions.

Disease: Noni shot hole

Pathogen: Noni shot hole is a leaf spot disease that is associated with an unidentified fungus.

Symptoms: Initial spots are tiny, maroon-colored specks on leaves and bracts. Specks develop into lesions (2-10 mm diameter) with bleached or tan centers and maroon margins, often surrounded by or accompanied by yellowing of leaf tissue around lesions. As the lesions mature the centers drop out, leaving the typical “shot hole” appearance. Infected leaves may abscise (drop) prematurely. Stems and fruits display no symptoms.

Disease distribution: Noni shot hole was first observed in the Puna district on the island of Hawaii in 2001, and has since been observed in the Hilo/Panaewa area. This disease is likely to become established wherever noni is grown in areas that receive high or frequent rainfall. Noni shot hole is common in noni plant nurseries, where plant crowding is common and overhead irrigation is used.

Epidemiology: Noni shot hole is favored by warm, wet, windy weather and high relative humidity. The fungal spores are dispersed by wind and by splashing rain water.

  1. Sanitation (removal of severely diseased leaves for the plant; removal and destruction of fallen infected leaves)
  2. Moisture and humidity management (ensure good drainage, control weeds, adequate plant spacing, pruning, minimize leaf wetness and reduce overhead irrigation).
  3. Protective spray applications of approved fungicides.
  4. Avoid spreading the pathogen on hands and tools during harvesting operations.
Notes: Noni shot hole has not been previously reported to occur in Hawaii or elsewhere in the world.

Last Updated on December 7, 2006