Pest of the Month July 2010 – Colletotrichum Leaf Spot on Red Sealing Wax Palm

  • Host:  Red sealing wax palms (Cyrtostachys renda Blume)
  • Symptoms:  Small, water-soaked dark green spots that expand into circular spots with tan to light brown centers bordered by water-soaked tissue on foliage.  The size of necrotic areas increases as spots coalesce.  Young leaves are susceptible.  Leaf petioles and sheaths are also infected.
  • Spread by: water splashing spores onto healthy leaves.  Spores can also spread by strong winds.
  • Management:  Sanitation – remove all dead and badly diseased leaves.  For leaves with only a few spots, prune away the affected section.  Discard potting soil from infected plants.  Limit moisture especially from overhead irrigation and from rain. Fungicides may be used in conjunction with sanitation and limiting moisture techniques.

Source: Colletotrichum Leaf Spot of Red Sealing Wax Palm, Dr. Janice Y. Uchida and Chris Y. Kadooka, University of Hawai’i at Manoa College of Tropical Agriculture and Human Resources Cooperative Extension Service Plant Disease PD-10, January 1997.