Tomato bacterial speck caused by the bacterium Pseudomonas syringae pv. tomato. The bacterium can survive in soil, plant debris or seeds. Disease is favored by cool, moist weather.

Tomato fruit damage. If disease is severe, plant growth is often reduced, resulting in delayed fruit maturity, decreased yield and marketability of the product. Image courtesy of University of Missouri Extension.

Bacterial speck of tomato caused by P. syringae pv. tomato is spread by splashing water. Lesions on leaflets are round and dark brown to black. Spots may coalesce and destroy a large area of the leaf tissue. Image courtesy of Dr. Alan Collmer, Cornell University.