Alphabetical Plant Listing

Early Blight

How to Identify, Prevent, and Treat Early Blight

What is Early Blight?

Early blight is a plant disease caused by the fungus Alternaria solani. It is commonly found in warm, humid climates and can affect a wide range of plants, including tomatoes, eggplantspepperspotatoes, and other nightshade crops. The disease causes dark, circular spots on the leaves, stems, and fruit of infected plants and can eventually lead to defoliation and reduced crop yields. 

What are the Symptoms?

To identify early blight, look for the following symptoms on the leaves, stems, and fruit of infected plants:

  1. 1. Circular or irregularly shaped brown or black spots on the leaves and stems
  2. 2. Dark, concentric rings within the spots
  3. 3. Yellowing and wilting of leaves near the base of the plant
  4. 4. Defoliation and premature death of leaves and branches
  5. 5. Brown or black lesions on the fruit, especially near the stem end

What Causes Early Blight?

The fungus is most commonly found in warm and moist conditions and is spread through the movement of spores in the air, as well as through splashing water that carries the spores from one infected plant to another. The pathogen can also survive in plant debris and soil, serving as a source of infection for new plants. In severe cases, the entire plant may be killed.

How to Prevent Early Blight?

Here are some steps to help prevent early blight in your garden or farm:

  1. Crop rotation: rotating crops can help reduce the buildup of early blight spores in the soil, reducing the risk of future infections.

  2. Proper garden maintenance: remove and dispose of any plant debris, such as fallen leaves or fruit, as they can serve as a source of infection.

  3. Irrigation: water your plants early in the day so that the foliage can dry out before nightfall. Overhead watering can spread the spores of early blight and encourage its spread.

  4. Remove the infected plants: It is important to remove the entire plant, including the roots, to prevent the fungus from surviving in the soil. Additionally, it is recommended to dispose of the infected plant material properly, such as by placing it in a sealed plastic bag and disposing of it in the trash. This will help to reduce the risk of the fungus spreading to other plants in the garden.

  5. Resistant varieties: growing resistant varieties of tomatoes and other plants can reduce the risk of early blight infections.

  6. Staking and pruning: pruning and staking plants can improve air circulation and reduce the amount of damp foliage, reducing the risk of early blight.

  7. Proper nutrition: providing your plants with proper nutrition and maintaining healthy soil can help reduce their susceptibility to early blight and other diseases.

  8. Mulching: A layer of organic mulch, such as leaves, straw, or wood chips, can help reduce the amount of moisture that reaches the soil and plant leaves. This can help to reduce the number of fungal spores that are able to reach the leaves and infect the plant. Additionally, mulch can provide a barrier between the soil and the plant, helping to keep the soil from splashing up onto the leaves and potentially spreading the fungal spores. It is important to keep the mulch a few inches away from the stem of the plant to prevent stem rot.

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AmBNPHOTO, Shutterstock

While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.

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