Leaf scald (Xanthomonas albilineans)
It is a vascular disease but differs from gummosis in that there is no oozing of gum from cut ends. Also leaf streaks due to leaf scald are different: they begin as sharply defined, narrow, white pencil stripes, which may extend the entire leaf length.
As the leaves grow older, the streaks tend to broaden and become more diffuse. There may be only one or several streaks on a leaf. Sometimes, instead of definite streaks, the entire shoot is chlorotic to nearly white. Affected plants become stunted and in advanced disease stage some shoots or the entire stool may suddenly wilt and die.
- Disease management measures for gummosis are applicable for leaf scald. Also heat treatment of planting for 3 hours at 500C provides effective control.