Ustilago tritic
Order: Ustilaginales Family: Ustilaginaceae
Blossom penetration type
Smut mean sooty (black) or charcoal like powder
Responsible for heavy losses when susceptible varieties with infected seeds are grown year after year
Cause losses 3-30 %
SYMPTOMS
Head of affected plants converted into black mass of spores & no grain formation
Affected young spike lets covered by silvery membrane
Only the awns of awned varieties escape transformation
Spores easily separate & blown off by wind leaving bear rachis.
DISEASE CYCLE
Air dried spores can survive for 12 months at 0-10 c
Pathogen is internally seed-borne
Infection occur when flowers are in full bloom & ovary is just developed after fertilization
Temp 22-25 °C
RH 60-85 %
MANAGEMENT
Solar energy treatment: Presoaking period of 4 hrs followed by 1 hr exposure to sun in summer
Hot water treatment: 4-5 hrs in a tub at ordinary temp, at 132 F for 5 min & 132 F for 7 min
Seed treatment with Vitavax & Baviston @ 2.5-3g/kg are systemic fungicides & effective
Resistant varieties (Perwaz, Watan, Sehar, Shafaq)
Only sow disease free seed