Problem Guide

Early blight and black fruit rot

Alternaria solani

Usually appears when fruits begin to set. First affects the lower leaves, then the stem and fruits. Large brown or black spots with concentric rings appear on them. Around the spot, the leaf begins to yellow and dies. It also attacks potatoes and eggplants. The fungus is resistant and persists for several years.

Late blight

Phytophthora infestans

Dark green or black spots appear and spread on the edges of the leaves. The same can appear on the fruits.

Septoria Leaf Spot

Septoria lycopersici

Forms light spots with dark edges, with black dots inside. Later the leaf yellows and falls off. Does not affect fruits. The fungus is resistant, survives winter.

Root Rot

Fusarium oxysporum

Common in tomato gardens. Thrives in warm, acidic soils. Infects the plant through the roots, spreads through the circulatory system. The first symptom is yellowing of the lower leaves; dark brown spots are found when the stem is cut. Can affect potatoes, peppers, eggplants.

Verticillium Wilt

Verticillium albo-atrum / Verticillium dahliae

Symptoms are very similar to root rot, the difference is that this fungus prefers cooler, neutral pH soils. Brown spots may also appear on the leaves in addition to yellowing.

Gray Leaf Spot

Stemphylium solani

Brown or black spots appear on all - old and young - leaves. As the spots expand, the leaf yellows and dies. Likes a humid environment, spreads by water droplets.

Brown Spot (Cladosporium Leaf Mold)

Cladosporium fulvum

Indistinct yellowish spots form on the leaves, and grayish, later brownish fungal growth appears on the underside. In high humidity, many spots appear, and the leaves begin to wilt.

Powdery Mildew

Erysiphe

Irregularly shaped white coating with deposits appears on the leaves, which later turn grayish. Drafts promote the disease.

Mold

Symptoms caused by various fungi. Mold only survives in high humidity.

Damping-off

Pythium, Rhizoctonia

More of a symptom than a disease. Affects only young seedlings: the stem browns and narrows at the roots, the seedling topples over.