Sunflower Head Rot: Rhizopus sp
Symptom:
-
Initial symptom appears as brown irregular water soaked spots on the back of ripening head usually adjacent to flower stalk.
-
Spots gradually enlarge and become soft and pulpy and get covered with superficial white mycelium which later becomes black.
-
Some seeds of the rotted heads shed and those which remain in the head taste bitter.
-
Injury before flowering or during the early stage of head development is unlikely to favour infection even though the inoculum may be present.
-
Maximum rotting is noticed at the soft dough stage.
-
Seed development is severely impaired depending on the stage of maturation at the time of Rhizopus infection and rot development.
Management:
-
To have effective control of the disease, simultaneous application of compatible insecticide and fungicide beginning with the completion of the flowering stage is suggested.
-
Injury to the head should be avoided as far as practicable.
-
Spray Mancozeb @ 2g/lit in case of intermittent rainfall at the head stage.
Virus Diseases of Sunflower:
- Spray Mancozeb 1000g/ha in case of intermittent rainfall at the head stage, directing the spray to cover the capitulum.
- Repeat fungicidal application after 10 days if the humid weather continues.
Source-
- TamilNadu Agritech Portal
