What are Spots on Tomato Plants?

Tomatoes are a popular homegrown vegetable, but sometimes tomato plants can develop spots on their leaves, stems, or fruits. These spots can be caused by a variety of factors, from fungal and bacterial diseases to environmental stressors. Identifying the cause of spots on your tomato plants is key to treating and preventing future problems.

Fungal Diseases

Fungal diseases are a common cause of spots on tomato plants. These diseases can be spread by water or soil and can thrive in warm, humid conditions. Some of the most common fungal diseases that affect tomato plants include early blight, late blight, septoria leaf spot, and anthracnose.

Early blight has symptoms of brown spots with concentric rings on the lower leaves of the plant. Late blight will cause black spots to form on leaves, often spreading to fruits. Septoria leaf spot will create brown, circular spots all over the plant, while anthracnose causes sunken black spots on fruits.

Bacterial Diseases

Bacterial diseases are another common cause of spots on tomato plants. These types of diseases can also be spread by water or soil and can build up over time. Some of the most common bacterial diseases that affect tomato plants include bacterial spot, speck, and canker.

Bacterial spot will create dark, greasy-looking spots on fruits and leaves. Speck will produce tiny black spots on leaves and fruits. Canker is more of a stem disease, causing yellow to brown patches to appear on stems.

Environmental Factors

Environmental factors can also contribute to the development of spots on tomato plants. Overwatering can lead to fungal diseases, and underwatering can cause the plant to be more susceptible to bacterial diseases. Sunscald can cause spots on fruits, and herbicide drift can cause spotting on leaves and stunt the growth of the plant.

Prevention and Treatment

The best way to prevent spots on tomato plants is to practice good hygiene and maintain healthy growing conditions. Proper watering and fertilizing can help prevent environmental stressors. Crop rotation and removing diseased plant matter can prevent the build-up of fungal and bacterial diseases.

When treating spots on tomato plants, it’s essential to identify the cause. Applying fungicides or bacterial treatments can help control the spread of disease, but it’s important to follow the instructions carefully. If you suspect herbicide drift, remove the affected leaves and move the plant to a new location.

Conclusion

Spots on tomato plants can be a frustrating problem for gardeners, but with proper prevention and treatment, they can be controlled. By identifying the cause of spots on tomato plants and taking appropriate action, gardeners can ensure a healthy and bountiful harvest.