Sunburn can occur on exposed fruit due to the loss of leaves, further reducing the marketability of the fruit. Fruit damage: The fruit can also be affected by Early Blight, with black or brown spots or scabs on the skin.On young seedlings, the stem lesions may completely girdle the stem, causing reduced plant vigor or death. Stem damage: Lesions on the stems are often lens-shaped with a light center and the same concentric rings seen on the leaves.As the disease progresses, the entire leaves may turn yellow and fall off, resulting in significant defoliation. Leaf damage: The first signs of the disease appear as small black or brown lesions on the leaves, which can enlarge to 10 mm or more in diameter with characteristic concentric rings.They can overwinter in infected plant debris and soil and survive on tomato seed or be introduced to tomato transplants, which can help them spread from one location to another.ĭamage Symptoms of Early Blight in Tomato Field.These two species are closely related and are capable of causing early Blight in tomato plants.

The causal organism of Early Blight is Alternaria solani and Alternaria tomatophila.

Repeat Cycle: The cycle of infection, sporulation, and spread continues, potentially leading to significant damage to the tomato crop and reducing yield.

Sporulation: The fungus continues to grow, producing more spores and spreading the infection to other parts of the plant and other plants nearby.

Establishment of Infection: Once inside the plant, the fungus begins to colonize the tissues, causing the plant to weaken and produce the characteristic dark, circular leaf lesions.

Penetration: The fungal hyphae penetrate the tomato plant through wounds or stomata, the tiny pores in leaves through which they exchange gases.

Germination: The spores come into contact with a suitable host, typically tomato leaves, and germinate in the presence of moisture.

Spore Production: The fungus produces spores on infected leaves and flowers, which release spores into the air and spread the disease to healthy plants.In small gardens, it's not always practical to rotate your crops, so good clean up and sanitation become even more important. Plant next year's tomatoes in a different section of your garden.A layer of mulch will help prevent spores on the ground from splashing up onto the lower leaves. Good air circulation is especially important during damp and rainy periods. Stake them so that they are not touching the ground and not all bunched together. Leave some space between your tomato plants so there is good airflow. Of course, it's impossible to keep the rain off your plants, but every little bit helps. Keep it off the leaves as much as possible by watering at the base of the plant only. Water aids the spread of Septoria leaf spot. Keep in mind that it may have spread to your potatoes and eggplants, too. It's important to dispose of all the affected plants far away from the garden and the compost pile. The fungus can over-winter on the debris of diseased plants. There's no evidence that this fungus is carried by seeds, but err on the safe side and don't save seed from infected plants. Thoroughly processing the tomato seeds you are saving will also help rid the seeds of lingering diseases. The Spruce Home Improvement Review Board.

Blight on tomatoes treatment organic