10 Top Tomato Plant Diseases 

Today we will cover the top tomato plant diseases because they can be lethal if they are not treated promptly.

One of the genuine joys of vegetable gardening is growing fresh tomatoes; yet, tomatoes are susceptible to a variety of diseases. Therefore, any illness must be caught early before it spreads to all of your tomato plants.

Top Tomato Plant Diseases - Tomato plant suffering from a disease.

What are the most common tomato diseases?

Many of the diseases and other problems listed here can be treated, if not cured, by routinely inspecting your plants and taking action at the first sign of a problem.

You might like these posts:

Top Tomato Plan Diseases

Tomato plant suffering from early blight

Early blight

Older leaves that come into contact with infected soil initially acquire dark patches with concentric rings. The yellowing of the surrounding leaf region is possible. Affected leaves may die before the fruits, exposing them to sunscald. It also affects stems and fruit, causing black leathery patches on the latter.

To manage early blight, remove any injured plants and tidy up any fallen garden debris properly. Compost any plants that have been harmed. Wet weather and stressed plants make an assault more likely. Copper and/or sulfur sprays can help stop the fungus from spreading.

 Tomato plant suffering from Late blight

Late blight

Another top tomato plant disease and this one is late blight. The first signs of the late blight disease are water-soaked spots on the leaves. They quickly expand into greasy purple patches. On the lower sides of the leaves, rings of grayish-white mycelia may emerge.

Any contaminated plants should be severely culled and removed from your land. Even if no symptoms are present, you should remove any surrounding plants that may be contaminated just to be safe.

Southern blight

Southern blight is a disease that thrives in temperatures exceeding 85 degrees Fahrenheit. It manifests itself as lesions along the soil line that spread higher up the stem. These lesions encircle the stem of the plant, causing it to wilt.

Following that, white mats of fungal filaments appear on the stem and adjoining soil. The microscopic tan to brown sclerotia that appear on the mat are a distinguishing feature of this condition.

As a preventative measure, use a fungicide. The fungus can survive for years in the soil. Compost diseased plants and plant waste instead of composting them. Crop rotation is important.

plant suffering from Verticillium wilt

Verticillium wilt

The first signs are yellow, V-shaped patches on older leaves. After that, the leaf turns brown and dies. Sunscald on the fruit is common when these leaves are lost.

Sanitizing tools and equipment between plants and rotating crops are two management approaches. Because water-saturated soil makes these diseases more susceptible, plant in a site with good drainage.

Diplocarpon rosae, rose black spot disease

Stemphylium gray leaf spot

Small, black dots can be visible on both the top and bottom surfaces of the leaves. The brown specks have a golden halo around them. The patches get larger and grayish-brown in color. The spots’ centers eventually fracture and fall out.

Remove all damaged plants and trash from the garden in the fall. Infected plants should not be composted. Most cherry and grape tomato plants are affected. Choose resistant plants. Avoid planting on infested soil by rotating crops.

Septoria leaf spot

Septoria leaf spot is frequently confused with late blight. It’s a fungus that only affects the leaves, not the fruit. The infection appears as little, black patches that grow to a diameter of 1/4 inch. The center of the spot becomes tan or gray, and the leaves finally wilt and fall off. The older leaves are hit first.

Control procedures usually entail removing spore sources. Always clean up the garden thoroughly at the end of the season, and dispose of any potentially infectious garbage in the trash.

Bacterial speck

Once plants have been infected with this disease, there is no cure. It thrives in chilly, humid conditions. Symptoms include small, dark spots with a yellow border on fruit and plants. The spots could be elevated, flat, or sunk.

Fortunately, cultural approaches and copper sprays can be used to control this disease. If your plants get this disease and you were using overhead irrigation, shift to a soaker hose or water at the soil level.


It primarily affects mature or overripe fruit on the vine in tomatoes. Small, slightly sunken circular lesions on the fruit are the predominant symptoms. They begin as a half-inch diameter and then turn tan. In the lesions, little black flecks appear. Large numbers of salmon-colored spores can grow on the surface of the lesions if the weather is humid.

Copper sprays provide some protection from this disease. To avoid soil contact, remove the bottom 12 inches of leaves. Only water the plant’s base, not the leaves. Crop rotation is important because spores overwinter in the soil.

Blossom end rot on tomatoes

Blossom end rot

Blossom end rot is thought to be caused by a shortage of calcium during the fruit set. Dark brown or black dots appear at the fruit’s blossom end and grow larger as the fruit rots. The areas appear to be wet.

To aid in the absorption of water and nutrients, add garden lime to the soil. Use a fertilizer that is high in phosphorus and low in nitrogen.

Buckeye rot

Both young and ripe fruit are affected by buckeye rot. The small brown spot will grow larger and form concentric rings, similar to a buckeye. As the disease advances, the firm lesion with smooth borders becomes soft and decaying, and the affected region may appear circular or oblong.

To combat this disease, remove any injured fruit from the tree, keep the future fruits away from the soil, and avoid surface water.

Which is the most serious disease of tomato?

The water mold fungus Phytophthora infestans causes late blight, a potentially fatal disease of tomatoes. During cool, damp conditions, late blight is most devastating. This pathogen can infect any portion of the plant. The lesions on young leaves are tiny and look like dark, wet patches.

What is the best fungicide for tomato plants?

On tomato fungi, the active component chlorothalonil is the most recommended chemical. It can be used until the day before selecting your tomatoes, indicating its minimal toxicity. When tomato plants are exposed to humid or rainy conditions that can produce blight, chlorothalonil can be employed.

Recent Posts