SESAMUM :: MAJOR DISEASE :: LEAF SPOT

Leaf spot - Cercospora sesami
Symptoms
The disease first appears on the leaves as minute water-soaked lesions, which enlarge to form round to irregular spots of 5-15 mm diameter on both the leaf surface. The spots coalesce to form irregular patches of varying size leading to premature defoliation. The infection is also seen on stem and petiole forming spots of varying lengths. Dark linear spots also occur on pods causing drying shedding.

Cercospora sesami -Symptoms

Pathogen
The hypha of the fungus is irregularly septate, light brown and thick walled. Conidiophores are produced in cluster and are 1-3 septate, hyaline at the tip and light brown coloured at base. Conidia are elongated, 7-10 septate, hyaline to light yellow, broad at the base and tapering towards the apex.
Disease Cycle
The fungus is externally and internally seed-borne. The fungus also survives in plant debris. Primary infection may be from the seeds and infected debris. The secondary spread is through wind-borne conidia.
Management

• Treat the seeds with Carbendazin or Thiram at 2g/kg.
• Spray with Mancozeb at 2kg/ha.