Effects of Temperature and Preinoculation Light Level on Severity of Syngonium Blight Caused by Xanthomonas campestris

The effect of temperature on growth of Xanthomonas campestris pv. syngonii isolated from Syngonium podophyllum ‘White Butterfly’ and X. campestris pv. dieffenbachiae isolated from Anthurium andraeanum was tested n vitro. Growth of X. campestris pv. syngonii occurred between 18 (65) and 32°C (90°F) (optimum 26°C [79°C]); growth of X. c. pv. dieffenbachiae occurred from 18 (65) to 34°C (93°F) (optimum 22°C [72°F]). Severity of syngonium blight was greatest for plants maintained at 30°C (86°F); no symptoms developed at temperatures below 26°C (79°F). Preinoculation light levels from 1600 to 5000 ft-c did not affect subsequent disease development on plants inoculated with X. campestris pv. syngonii.