3. In India disease occur in all states mostly cooler
regions and moist northen parts. Untreated seeds cause–
23% to 30% infected head in fields.
In Punjab(1951– 52) cause 3- 30% damage.
In 1988-89 loss of Rs 1.05 billion annually.
Kalyan Sona have <0.5% damage.
After practice of Rice – Wheat rotation cause increase
of 2-5% damage.
LOOSE SMUT
4. •Disease occur in ear head stage.
•Diseased head reach at same time or earlier than the normal
heading stage.
•In ears mass of blackish powder – smut spores develop in
young spikelets initially covered by delicate silvery
membrane later rupture and expose dark, olive brown,
powdery mass in place of normal spikelets.
•Blown by wind - leaving rachis alone
SYMPTOMS
6. •Unicellular pale, olive – brown, spherical to oval, minute, echinulated
smut spores (chlamydospores).
Germination occurs when spores falls on feathery stigma of health
wheat flowers. Later produce germ tubes reaching inside ovary.
•1 week – germ tubes ovary reached
•10 days- ovules reached
•Hyphae enter between endosperm and nucellus
•3 weeks - branch reach lower end of raphe and reach scutellum.
•4 weeks – it grow along rudimentary vascular bundles
•1month - all embryo parts except root primordia have hyphae
•Dormant mycelium in seed become active when sown in next
generation
PATHOGEN
9. • Disease is internally seed borne
• Pathogen survive in embryo as secondary mycelium
• Infection – systemic
•Smut spores – survive 5 -6 months
•Dispersed by wind
• Temp. – 23° C
• Smut spore – 18 - 20° C
• R. H – 60 - 85%
• pH – 3
•Deep sowing (7.5cm) favour disease
•120-130 kg N/ha susceptible to loose smut
•Loose spikelet more susceptible than compact
ENVIRONMENTAL CONDITION
10. Hot water treatment (Jensen 1886): soak seeds in cool water
(19-30ºC) for 4 hr then soak in hot water (54ºC) for 10 min
Solar heat treatment (Luthra, 1953): soak seeds in cool
water for 4hr (8am-12Noon) then spread in bright sun (44ºC)
for 4 hr (12Noon-4pm)
CHEMICAL:
•In India Vitavax (carboxin), Bavistin (Carbendazim) used.
•Vitavax with thiram, maneb, effective and reduces cost.
•Tebuconazole (Raxil) 1.25%is effective and economical
MANAGEMENT
11. BIOLOGICAL:
•T.viridae, T. harziaum, Bacillus subtilis control loose smut of
wheat.
•Trichoderma viridae, T. harzianum. P.fluorescens.Gliocladium
virens, in combination with half dose of Vitavax (0.125%).
Resistant varities:
Punjab varities: S 227, PV18, WG 307, C302.
Uttar Pradesh varities: NP 710, 718, 761, 770.
Susceptible varities:
Sonara 64,Lerma Rojo
MANAGEMENT
14. Stem smut or Stripes smut – first observed in South
Australia in 1868
Disease observed in India – Punjab, Haryana, Madhya
Pradesh, Delhi, Rajasthan, and Himachal Pradesh.
Late 1970s – cause 39-78% loss in Rajasthan
In 1918 Indian subcontinent disease occur in India
now in Pakistan (undivided Punjab including Haryana,
North West Frontier Province)
FLAG SMUT
15. Disease of stem, culm, and leaf of wheat plants.
Commonly affected parts are leaf and leaf sheath.
Infection from late seedling to maturity
Leaves become twisted ,drooping(flagging),withering
and leaves shred and whole plant die.
Culm remain sterile and bears no grains.
Grey to greyish-black, slightly swollen bands running
parallel to veins of older veins and leaf sheath. Bands
are development of sori – rupture exposing a black
powdery mass of spores.
SYMPTOM
17. •Spores borne in tiny balls consist of 1-6 mostly 3, fertile, bright
brown spores surrounded by layer of flattened sterile peripheral
cells.
•Spores are smooth walled, brown, globose.
•Smut spores germinate into promycelium with 1-2 septa and
produce 2-6 cylindrical basidiospores at distal end.
•Basidiospores germinate to produce primary mycelium.
•Opposite mating type of primary mycelium fuse and form
dikaryotic secondary mycelium that becomes systematic.
•Dikaryotic mycelium later form black stripes of smut sori.
PATHOGEN
19. Temp – 18 – 24ºC
Max temp – 32ºC
Mini temp – 5ºC
pH – 5.1 – 5.7
Spores present in the soil germinate at time of seedlings germinate and cause
infection
ENVIRONMENTAL CONDITION
21. CHEMICAL:
CuSO4 – 50 g /50 kg seeds
Fungicides – Bavistin, Vitavax – good control of seed borne infection and
protects seedling against soil – borne inoculum.
CULTURAL:
Rotation, early sowing of crop burning of stubbles, and hot weather
cultivation.
Sown in end of October instead of November – December
RESISTANT VARITIES:
WG 189, VL 426, HD 2117, HW 161, HB 121 and HB 113
MANAGEMENT
