1.Alternaria leaf blight:
-----------------------------

Alternaria helianthi

Symptoms:

 The fungus produces brown spots on the leaves, stem, sepals and petals.
 The lesions on the leaves are dark brown with pale margin surrounded by a yellow halo.
 The spots enlarge in size with concentric rings and become irregular in shape.
 Several spots coalesce to form bigger irregular lesions leading to drying and defoliation.

Management:

 Remove and destroy infected plant debris.
 Rogue out weeds at periodical intervals.
 Sow the crop early in the season (June).
 Treat the seeds with thiram or carbendazim @ 2 g/kg.
 Spray mancozeb @ 1kg/ha.


Rust
2.Rust:
-----------

Puccinia helianthi

Symptoms:
Small, reddish brown pustules covered with rusty dust appear on the lower surface of bottom leaves.

 Infection later spreads to other leaves and even to the green parts of the head.
 In severe infection, when numerous pustules appear on leaves, they become yellow and dry.
 The black colored telia are also seen among uredia on the lower surface.

Management:

Remove and burn the infected plant debris in the field

 Remove the volunteer sunflower plants.
 Spry Mancozeb @ 1 kg/ha.