Sunflower Downy Mildew: Plasmopara halstedii
Symptom:
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The disease spreads rapidly through seeds.
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Symptoms of the disease are evident as seedling damping off, systemic infection, local foliar lesions and basal root or stem galls.
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First symptoms are yellowing of the first pair of true leaves.
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Sunflower plants carrying systemic infection are severely stunted and leaves are entirely chlorotic.
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Affected plants bear abnormally thick, downward curled leaves showing prominent yellow and green mottling.
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The stem becomes brittle. Small angular greenish yellow lesions may appear on leaves as a result of secondary infection.
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Fungal growth is visible at lower surface.
Management:
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Seed treatment with Metalaxyl at the rate of 3 g per kg of seed has been found to give effective control.
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Choice of planting sites and disposal of infected crop residues also give a fairly good control.
Source-
- TamilNadu Agritech Portal
