Tomato Early Blight Symptoms: Identifying the Signs of Infection

Early blight is one of the most common diseases affecting tomato plants, causing significant damage to leaves, stems, and fruit. As a gardener or farmer, it is essential to recognize the signs of infection to take prompt action against this devastating disease.

The first symptoms of early blight typically appear on the oldest, lowest leaves as small pinpoint lesions near leaf centers. These initial infections can easily spread, leading to the formation of characteristic bullseye-patterned spots. As the disease advances, these spots will proliferate on affected leaves, often forming dark concentric rings similar to those found on infected potato plants.

On older, more robust tomato plants, early blight symptoms are usually oval or irregular in shape and can eventually form brown, sunken spots on stems. In seedlings, collar rot can occur, causing the seedling to wither and die. The disease can spread rapidly, infecting leaves at increasingly higher positions on the plant.

As infected leaves turn yellow, develop fissures, and die, they may remain attached to the plant or drop to the ground, where they can serve as a vector for the disease to spread further. In severe cases, early blight can cause extensive premature defoliation in potatoes, reducing crop yields significantly.

The 'bullseye' spots associated with early blight are a distinctive feature of this disease. These ridged spots typically start small and grow, eventually forming large rings of tissue around the lesions that turn brown or black. Early blight is caused by the fungus Alternaria solani, although closely related species like Alternaria tomatophila can also cause infection.

Early blight is a pervasive disease that affects multiple parts of the plant, including leaves, stems, and fruit. It is essential for gardeners and farmers to be aware of these tomato early blight symptoms to take prompt action against this devastating disease. With proper identification and treatment, it is possible to mitigate its impact on crop yields and ensure a healthy harvest.

References:

* Clemson University – USDA Cooperative Extension Slide Series (Image source)

* CC BY 3.0 US

Tomato early blight symptoms