Black stem of sunflower

Symptoms

• The disease already shows at the 3–4 true leaf stage, but most often during ripening, as blackening of the stem.
• Affected leaves wilt, dry out and stay hanging on the stem.
• Brown, diffuse spots appear on the upper side of the heads and often cover the whole head.

Signs of the pathogen

In the affected areas, black pycnidia form under the epidermis, arranged in concentric rings.

When to look

• The first signs of the disease are recorded at the inflorescence formation stage.
• More intensive development of the disease is recorded in the periods from flowering to head ripening.

No rate and no spray timing here: both come from the label and the register.

Source of infection

The inoculum persists on plant residues and in the soil.

Favourable conditions

Optimal conditions for disease development: sufficient rainfall and an air temperature of +20…+25 °C.

Every fact rests on a quote from its source, and each quote was checked against the page it is printed on.

1. EPPO Global Database · European and Mediterranean Plant Protection Organization
2. Станкевич С. В., Положенець В. М., Немерицька Л. В., Журавська І. А., «Моніторинг хвороб сільськогосподарських культур», навчальний посібник, 301 с. · Інститут біоенергетичних культур і цукрових буряків НААН, Державний біотехнологічний університет; Житомир: Рута, 2022 · p. 177
3. Прогноз фітосанітарного стану агроценозів України та рекомендації щодо захисту рослин у 2025 році · Держпродспоживслужба, НААН, НАН · p. 111, 112