Bacteria multiply rapidly by simple cell division and absorb nutrients from their immediate environment. Bacterial spot - Small, dark brown leaf spots. Spots on wet leaves will have a greasy appearance. This disease is most important in the eastern half of Oklahoma where rainfall and humidity levels are moderate to high. Bacterial spot reduces tomato yield and quality by defoliation and spotting of fruit.
Bacterial spot is also a serious disease of pepper.
The bacteria survive on diseased plant debris and on tomato seed. The bacteria enter plants through natural openings or wounds and form leaf spots that are dark brown in color. The leaf spots produced in bacterial spot are easily confused with those produced in bacterial speck and the initial symptoms of the fungal diseases Septoria leaf spot and early blight. In addition to the leaf spots produced, a general yellowing of heavily spotted areas on leaves may occur, followed by leaf scorch. Fruit spots are conspicuous on green fruit and appear raised and scabby, dark brown in color, and are up to one-third of an inch in diameter.