Alternaria is a type of fungus that causes diseases in plants. It's a common problem in gardens and can affect a wide range of plants, including vegetables, fruits, and flowers. The symptoms of Alternaria include yellowing leaves, black spots, and rotting fruit. If left unchecked, it can lead to significant damage and reduce crop yields.
Many plants are susceptible to Alternaria, including tomatoes, peppers, cucumbers, and squash. The fungus thrives in warm, humid conditions and can spread quickly through spores. There are many organic and natural solutions to control Alternaria. Remember, prevention is key. Here are some methods you can try:
- Remove infected leaves and stems to prevent the fungus from spreading.
- Improve air circulation around plants to reduce moisture.
- Water plants at the base to avoid getting water on the leaves.
- Use natural fungicides like neem oil and copper-based products.
- Introduce beneficial microbes to outcompete pathogens and produce anti-fungal compounds.
Symptoms typically manifest as round, brown lesions with concentric circles and a crack across the middle. Yellow haloing around these lesions is usually visible as well. These spots are usually pretty small at the beginning stage but can grow to be half an inch (or more) in diameter. As the pathogen progresses, lesions will begin to congregate until necrosis takes over large portions of the leaf. Broccoli and cauliflower heads will begin to show brown rot spots and deteriorate.
Early applications of a biological fungicide such as Actinovate, active ingredient: Streptomyces lydicus, can help ward off Alternaria and other diseases like Pythium, Botrytis, Fusarium, Ohytopthora, Sclerotinia, Powdery Mildew, Bacterial Spot, and Early Blight.