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FIG.01 — Early blight (Alternaria), diseaseTap to enlarge
Plant part
Leaf · Stem · Fruit
P. persimilis
RESTRICTED
DiseaseProblem 01 / 32
Early blight (Alternaria)
Symptoms
Necrotic brown spots with concentric “target” rings on older leaves; yellow halo; may reach stems and fruit.
How to verify
Compare the photos above with the plant, and check the symptom description against the look-alike records below before acting. The source guide does not carry a separate laboratory verification note for this record.
Next step
Remove lower infected leaves and crop debris; mulch and use drip irrigation. Improve airflow and rotate crops.
Product / label options
PRODUCT / LABEL OPTIONS: If needed, use a tomato-labeled fungicide such as difenoconazole, tebuconazole, chlorothalonil, or azoxystrobin, rotating FRAC groups and following the label.
Active ingredients
chlorothalonilmancozebmetiramcymoxanil + mancozebtebuconazoledifenoconazoleazoxystrobin
Organic active ingredients
neem oil
P. persimilis: allowed / avoid
PERSIMILIS STATUS: RESTRICTED. Mancozeb can damage beneficial mites; use before release and allow at least 7 days before releasing Phytoseiulus persimilis.
Label matters
Active ingredients below are examples, not universal prescriptions. Confirm the diagnosis; use only products registered for tomato and the target problem in your country; and follow the current label for dose, pre-harvest interval, worker protection, compatibility and re-entry. Rotate IRAC/FRAC modes of action. When symptoms are uncertain, obtain a laboratory or extension diagnosis. Integrated pest management (IPM)—sanitation, resistant varieties, irrigation management, monitoring and biological control—should be the first line of defense.
Look-alikes to rule out
