Marginal necrosis and intercostal leaf spots of cocoyam infected by Xanthomonas campestris pv. dieffenbachiae.

(...) Inoculation of bacteria into intercostal or marginal tissue produced symptoms normally observed regardless of lesion type from which the strain was originally recovered. Numbers of intercostal and marginal lesions were independent of strain source. An average of 11 marginal lesions per leaf developed when actively guttating plants were mist-inoculated, but only 2.4 marginal lesions per leaf developed on nonguttating plants. Great numbers of intercostal lesions were evident when plants were inoculated during midafternoon than when bacteria were sprayed on leaves early in the morning (...)