Symptoms can occur within three days of infection and plants can collapse so rapidly that they may appear to have been damaged by frost (Stevenson and Bolkan 2014). Above 86☏, infections will stop, but the pathogen can still survive and cause new infections when temperatures again become favorable. Infections occur during periods of cool, moist weather, when temperatures are between 66 and 72⁰F. Infected vines also rot and have a foul odor to them. Infected green fruit has brown or olive-colored lesions and often develop a soft rot.

On the underside of leaves, growth of a white mold becomes visible on the lesions. Foliar infections start out as small, water-soaked lesions that enlarge rapidly and become pale green. SymptomsĪll above-ground parts of tomato and potato plants can become infected. The disease is caused by Phytophthora infestans and is infamous for causing the potato famine in Ireland in the 1840s. Late blight is a disease that can infect many solanaceous plants such as tomato, potato, and solanaceous weeds, however, there have been no reports of late blight in pepper or eggplant. Late Blight Symptoms on Tomato Fruit Casual Agent

Late blight tomatoe