Barley powdery mildew control strategies

A combination of resistant varieties, good plant health and effective fungicides is required to prevent economic loss from powdery mildew outbreaks in barley.

Key points

• Barley powdery mildew is a windborne fungal disease that survives between seasons on stubble, plant residues and occasionally barley volunteers.
• New strains of powdery mildew have been detected on commercial barley varieties previously considered resistant.
• High disease levels can reduce yield by five to 15 per cent.
• Before sowing, consider the varietal resistance rating and be aware of disease risk on-farm.
• If using a barley variety with a resistance rating less than Resistant (R), consider treating with a fungicide at seeding.
• Monitor at-risk crops from early tillering, then every seven to 10 days.
• If powdery mildew is detected, apply an appropriate fungicide immediately, based on varietal resistance level, growth stage, severity of infection and likely future weather conditions.
• Seed or in-furrow fungicide treatments can provide good early-season protection.
• Repeated applications of the same fungicide group increases the risk of fungicide resistance developing.