Symptoms appear on leaves, petioles, stem,
sepals and petals.
Symptoms appear as dark brown irregular leaf
spots with very dark border and grey centre.
Spots first appear on lower leaves, later
spread to middle and upper leaves.
At later stages spots may be formed on
petioles, stem and ray florets.
In later stages the leaf lesions may coalesce
causing the leaf to wither.
The disease affect the quality of seeds by
reducing the germination percentage.
The infection of the disease causes losses up
to an extent of 10 - 30%.
Pathogen survive on seed, host debris and
Successive crops of sunflower may also help
to multiply the pathogen.
Hot weather and frequent rain during the milk
and wax stages of development favour infection.
The fungus is reported to produce a toxic
metabolite, a phenolic substance in culture and leaf tissues.
Disease development is favoured by 25-27o
C temperatures with at least 12 hours of wet foliage.
Fluffy fungal growth is seen on the back side of the
head which spreads to entire head region due to which the whole
In severe cases, the seeds are transformed into a black
Early symptoms are not visible on infected
plants, but they become weak, mature early and when dry, show a
presence of black ashy discolouration of the stem.
Black microsclerotia are formed in huge
number on the affected portion.
Sometimes the disease causes seedling blight,
damping off, root rot or basal stem rot.
Whenever the soil becomes dry and the soil
temperature rises then irrigation should be provided.
In endemic areas long crop rotation should be
In systemic infection, plants are severely
stunted, chlorosis causes abnormally thick, downward curled
leaves and whitish downy growth develop on lower surface of the
The flower heads are remain sterile and
Local foliar lesion symptoms are
characterized by small angular greenish yellow spots on leaves.
Infected plants exhibit discoloured, scurfy
roots having gall on primary root.
Affected plants dry and get away by wind.
Apply and incorporate fungus Coniothyrium
minitans before sowing as it invades and destroy the pathogen in
Seed treatment with Psuedomonas fluorescens
or P. putida strains protect sunflower from sclerotinia
infection during seedling stage.
The disease produces white powdery growth on
The infected plants show irregular yellow or light green
patches alternating with normal green areas.
Cupping and malformation of leaves, poorly developed root
and reduction of pollen fertility are other symptoms.
With Support of TIFP, Ministry of Science & Technology, Dpt.
of Scientific & Industrial Research, GoI Designed And Developed at Directorate of Instrumentation, JNKVV,