Late blight—Phytophthora infestans
Phytophthora infestans has a wide host range, including tomato, potato, pepper, and eggplant.
On leaves, late blight lesions typically first appear as irregular, small pale to dark green water-soaked
spots that are surrounded by a zone of yellowish tissue. Lesions may expand rapidly and become brown to
purplish black. White sporulation of the fungus may be observed at the periphery of lesions, principally
on the underside of leaves. On stems and petioles, lesions are brown to black and may also support sporulation
of the fungus. Fruit discoloration usually begins on the upper side of the fruit. Affected fruit remain
Avoid sprinkler irrigation. Destroy all tomato, potato, eggplant, and pepper debris after harvest.
blight infection on tomato leaves