Tomato Diseases

Tomato Diseases

Symptoms appear first on the oldest leaves then later on younger leaves. The leaves turn yellow and dry up often without wilting. The leaves drop prematurely and shoot tips wilt slightly during the day. As defoliation progresses, the leaves may curl upward at the margin but remain alive. Internal woody stem tissue is darkened, especially near the bottom of the stem. The fungus persists in the soil many years. There is no chemical control. Use resistant varieties when possible.

Fusarium Wilt

Leaf yellowing, starts at the bottom of the plant and works up. One-sided wilting occurs on the entire plant or individual leaves. Yellow leaves wilt before they die. Individual shoots, then entire plants, wilt permanently then die. Woody stem tissue is discolored throughout the plant. The fungus can persist in the soil for many years. There is no chemical control, so use resistant varieties.

Bacterial Wilt

Plants wilt suddenly without leaves turning yellow. The pith becomes watersoaked and later turns brown and hollow. Woody stem tissue turns brown and often many roots form on the stem. There is no chemical control.

Bacterial Canker

An early symptom is leaflet wilting. On older plants, leaves die from the margin inwards. Often, the leaflets on one side of the leaf are affected first. The plant may wilt and die or persist in a wilted condition. Yellowish white streaks form on the leaf petioles and stem. The streaks later develop into elongated cankers. The fruits may be spotted. The bacteria can survive a year in diseased crop residues.

Stem Rot

A dry rot girdles the stem at ground level causing wilting and death. Black pea-like structures are produced in the stem and these may persist for many years in the soil. Disease development is enhanced by cool wet weather.

Early Blight

This disease is usually more of a problem on older plants. Dark brown spots, with dark concentric rings, develop on the oldest leaves. Infected leaves die resulting in early defoliation and sunscalded fruit. On fruits, the spots begin at the stem end. The spots develop into black leathery sunken areas which may have concentric rings. The disease overwinters in infected refuse and is enhanced by heavy dew, rainfall, and low vigor plants. Use Chlorothalonil(0) or copper(0).

Late Blight

Irregular, greasy appearing, grayish areas develop on the leaves. The areas expand rapidly during moist conditions. A downy white mold appears at the margins, on the undersides of the diseased areas. On fruit, grayish green watersoaked spots enlarge to indefinite size and shape. The areas become dark brown, firm, wrinkled and have a definite margin. The disease is enhanced by wet cool weather. Use sprays of Chlorothalonil(0) or copper (0).

Septoria Leaf Spot

Many small, circular, gray spots form on the leaves. The spots have dark borders and a few black specks may be seen in the spots. The disease is favored and spread by wet weather. Use sprays of copper(1).

Bacterial Spot

Dark, greasy spots form on leaves and stems. Small dark raised spots, sometimes with watersoaked margins form on the fruit. The spot enlarges to 1/8 to 1/4 inch and becomes brown and scabby. Wet weather favors the disease and splashing water spreads it. Use sprays of copper(1).

Anthracnose

Anthracnose is common on ripe fruit and begins as small, circular, slightly sunken spots. The spots increase in size, the centers darken, and several spots may merge. Green fruit can become infected but symptoms don't appear until the fruit ripens. The disease is prevalent on overripe fruit in contact with the soil and is promoted by wet weather. Use sprays of Chlorothalonil(0) or copper(1).

Soil Rot

The fruit develop brown, slightly sunken spots, about 1 inch in diameter. Dark, narrow, concentric rings are visible in new spots. The center cracks open. The disease is favored by wet weather and ripe fruit in contact with soil. No chemical control is listed.

Bacterial Speck

Small black specks develop on leaves, fruit and stems. On small, green fruit, the specks are superficial and slightly raised. The specks are 1/16 inch in diameter and tissue around the speck stays green longer than surrounding ripening tissue. Wet weather enhances disease development. No chemical control is listed.

Ghost Spot

Whitish, 1/8 to 1/4 inch rings develop on green tomatoes. The symptoms mark where a fungus entered the fruit but died. Low temperatures and high humidity make the problem worse. No chemical control is listed.

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