Early blight can cause severe damage to tomatoes and symptoms can be on any of the above ground parts of the plant including leaves, stem and fruits.
The lesion start with small yellow sections on the leaf that starts to turn brown, and this is especially noticed in leaves that are close to the ground.
Advanced symptom includes oval shaped lesions with a yellow chlorotic region around the lesion. The lesions may or may not have concentric rings.
At later stages early blight causes severe yellowing and blights of the leaves leading exposing the fruits to sunsclading and reduced yield.
Concentric lesions on the stem is a characteristic symptom for early blight. The center of lesions also tend to crack as the lesion ages.
Fruit lesions can be noticed as sunken leathery sections on the fruits and black colored sporulation on the fruits may also be seen on green or ripe fruits.
Even though not often seen, early blight can also cause large lesions on the fruits. These spots are dark and sunken and can occur on the side as above or on the end of calyx of the fruit.