The document describes 9 diseases that affect sorghum crops: 1. Anthracnose or Red leaf spot caused by Colletotrichum graminicola causes small red spots on leaves. 2. Rust caused by Puccinia purpurea causes small reddish brown flecks and pustules on leaves. 3. Ergot or Sugary disease caused by Claviceps sorghi leads to honeydew secretion and blackened heads. 4. Head Mould / Grain Mould / Head Blight caused by several fungi causes pink or black mold on infected grains. 5. Leaf Blight or Leaf Stripe caused by Exserohilum tur

2. S.N
Diseases Causal organism
1 Anthracnose or Red leaf spot Colletotrichum graminicola
2 Rust Puccinia purpurea
3 Ergot or Sugary disease Claviceps sorghi or Sphacellia sorghi
4 Head Mould / Grain Mould / Head Blight Several Fungal genera
5 Leaf Blight or Leaf Stripe Exserohilum turcicum or
Trichometasphaeria turcica
Syn: Helminthosporium turcicum or
Drechslera turcicum
6 Grain Smut / Kernal Smut / Covered Smut Sphacelotheca sorghi
/ Short Smut Sporisorium sorghi
7 Charcoal Rot / Hollow Stem / Stalk Rot Macrophomina phaseolina
Blight
8 Downy Mildew or Leaf Shredding Peronosclerospora sorghi
9 Phanerogamic Parasite Striga asiatica or Striga densiflora
( Striga or Witch Weed )

3. Symptoms :
• Small red coloured spots on leaf.
• Whitish centre encircled by red, purple or brown margin.
• Numerous small black dots are seen on the white surface of the lesions which
are the fruiting bodies (acervuli) of the fungus, Many lesions coalesce and kill
large leaf portions.
• In midrib region, elongate elliptical, red or purple regions with black acervuli
are formed
• Development of circular cankers on Stalk and inflorescence
• Infected stem when split open shows discoloration, which may be continuous
over a large area or more generally discontinuous giving the stem a marbled
appearance.
Disease cycle
Primary Infection : Fungus present in Seed, and IPD
Collateral host: Johnson grass, Sudan grass, maize, barley
and wheat
Secondary Infection : Wind born Conidia

4. Management
 Destruction of infected plant debris and collateral hosts
 Crop rotation with non-host crops
 Grow resistant varieties like SPV 162, CSV 17, Texas Milo and Tift sudan
etc
 Treat the seeds with Captan or Thiram @3 g/kg.
 Spray the crop with Mancozeb @0.25% or carbendazim@0.1%

6. Puccinia purpurea
Symptoms
 Small reddish brown flecks on the lower surface of the leaf
 Pustules (uredosori) appear on both surfaces of leaf as purplish spots which rupture
to release reddish powdery masses of uredospores.
 The pustules are elliptical and lie between and parallel with the leaf veins. Pustules
are surrounded by a reddish or yellow halo
 Teliopores develop later sometimes in the old uredosori or in teliosori, which are
darker and longer than the uredosori
Disease cycle
Primary Infection : long cycled rust
Alternate host Oxalis corniculata (aecial and pycnial stage)
Secondary Infection : Wind born uridospores

7. Favourable Conditions
 Low temperature 10 to 120C
 rainy weather
Management
 Grow resistant varieties like CSH 5, SPV 13, 81, 126, PSH 1, CSV 17, etc.
 Remove and destroy the alternate host Oxalis corniculata.
 Spray the crop with Mancozeb @0.25%
 Dusting of sulphur@25 kg/ha
Oxalis corniculata

9. Symptoms
 The disease is confined to individual spikelets.
 Secretion of honey dew (creamy sticky liquid) from infected florets. The honey dew
secretion attracts large number of insects and ants which help in spreading the disease.
 Often the honey dew is colonized by Cerebella sorghivulgaris which gives the head a
blackened appearance.
 Under favourable conditions, grain is replaced by long (1-2cm), straight or curved, cream to
light brown, hard sclerotia.
 At the base of the affected plants white spots can be seen on the soil surface, denoting the
drops of honey dew which had fallen on the soil.
Disease cycle
Primary infection : Sclerotia germinates & produce ascospores
Secondary Infection : Air and insect born conidia & conidia also spreads through
Wind splash rain water
Favourable Conditions
1. High rainfall
2. High humidity during flowering season.
3. Cool night temperature (20-25 0C)
4. Cloudy weather during anthesis
5. Male sterile lines are highly susceptible.

10. Management
 Adjust the date of sowing so that the crop does not flower during the periods of high
rainfall and high humidity.
 Grow resistant varieties like SPV 191, CSH 5, SPH 1 and CS3541.
 Deep summer ploughing
 Soaking seeds with 2% saline solution will aid to remove ergot infested seeds, as ergot
infested seeds will float in the salt solution.
 Seed treatment with fungicides such as Captan or Thiram@4g/kg seed
 Spray Ziram (or) Zineb (or) Captan (or) Mancozeb @0.2% at emergence of earhead (5-10 per
cent flowering stage) followed by a spray at 50 per cent flowering and repeat the spray after
a week, if necessary.
 Control of ergot with fungicides such as Propiconazole or Tebuconazole has proved to be
cost effective in seed production plots.

12. Symptoms
 If rains occur during the flowering and grain filling stages, severe grain moulding can occur.
Infected grains are covered with pink or black mold and such grains disintegrate during
threshing process. Fusarium semitectum and F.moniliforme develop a fluffy white or
pinkish colouration. C. lunata colours the grain black. Fungi from many genera have been
isolated from the infected sorghum grains and the most frequently occurring genera are
Fusarium, Curvularia, Alternaria, Aspergillus, Cheatomium, Rhizopus, Helminthosporium and
Phoma. Moldy grains contain toxic mycotoxins and are unfit for human consumption and
cattle feed.
Disease cycle
• The fungi mainly spread through air-borne conidia. The fungi survive as parasites as well as
saprophytes in the infected plant debris.
Favourable Conditions
• Wet weather following the flowering favours grain mould development and the longer the
wet period the greater the mould development. Compact ear heads are highly susceptible.

13. Management
 Adjust the sowing time
 Grow resistant varieties like GMRP 4, GMRP 9, GMRP 13 and tolerant varieties like CSV
15.
 Seed disinfestation with Thiram@0.3% will prevent seedling infection.
 Spray Mancozeb (0.25%) or captan (0.2%) or captan 2g + Aureofungin 200ppm per liter,
in case of intermittent rainfall during earhead emergence, a week later and during
milky stage.

15. Leaf blight or leaf stripe Exserohilum turcicum or Trichometasphaeria turcica
(Syn : Helminthosporium turcicum or Drechslera turcicum)
Symptoms
 The leaf blight pathogen also causes seed rot and seedling blight of sorghum.
 Small narrow elongated spindle shaped spots in the initial stage.
 Later they extend along the length of the leaf becoming bigger.
 On older plants - Long elliptical necrotic lesions, straw coloured in the centre with dark
margins.
 Many lesions coalesce on the leaves, destroying large areas of leaf tissue
 giving the crop a distinctly burnt appearance leading to premature drying of leaves.
Disease cycle
Primary Infection : Fungus present in Seed, Soil and IPD
Secondary Infection : Seed or Wind born Conidia
Favourable Conditions
• Cool moist weather,
• High humidity (90 %)
• High rainfall

16.  Use disease free seeds.
 Crop Rotation with non susceptible crops
 Collect and destroy IPD
 Seed Treatment with Captan or Thiram at 4 g/kg.
 Spray the crop with Mancozeb@0.25% at the age of 40 days and the spraying have to be
repeated twice at 15 days interval
 Tift-Sudan is resistant to this disease

18. Symptoms
 The disease appears at the time of grain formation in the ear.
 The individual grains are replaced by smut sori (dirty white to gray ) and are covered with a
tough white cream to light brown skin (peridium).
 The glumes are unaltered and may be found adhering to the sides of the sorus.
 Sometimes the stamens may develop normally protruding out of the sorus.
 Ratoon crops exhibit higher incidence of disease.
Disease cycle
Primary Infection : Externally seed borne and systemic
Secondary Infection : Wind born Sporidia

19.  Use disease free seeds.
 Grow resistant varieties like T 29/1, PJ 7K, PJ 23K, Nandyal and Bilichigan.
 Treat the seed with fine sulphur powder @0.5% or Captan or Thiram @0.3%.
 Follow crop rotation.
 Collect the smutted ear heads in cloth bags and dip in boiling water.

21. Charcoal rot or hollow stem or stalk rot blight
Macrophomina phaseolina
Symptoms
 Sudden Wilting and Death of the diseased plant resulting in Lodging.
 If the infected stalk is split open, the pith is disintegrated with longitudinal shredding of the
tissue into fibers. Small black sclerotial bodies are seen in the infected tissues.
 The stem, breaks near the ground level. Premature ripening takes place and the heads are
poorly developed.
Disease cycle
Primary Infection : sclerotial bodies present in the Soil, IPD, Weed
Host
Secondary Infection : sclerotial bodies carried through Rain or irrigated
water
Favourable conditions
 Soil temperature 35 0 C
 Moisture stress conditions preceding crop maturity
 High dose of nitrogenous fertilizers

22. Management
 Thin plant population (60,000 plants/ha)
 Collected and burning of infected plants along with trash
 Avoid moisture stress at flowering
 Grow resistant varieties like E-36-1, CSV 5, CSH 7-R, SPV 126 and SPV 193.

24. Symptoms
 Downy whitish growth is produced on the lower surface of the leaves.
 White streaks appear on both the surfaces of the leaves.
 The tissues then tear along the streaks causing Leaf shredding of the leaves. The tissue then
turns brown in colour. Numerous oospores are found in the shredded leaves.
 The affected parts are stunted and sterile.
Disease cycle
Primary Infection : Oospores present in the Soil.
mycelium , seeds
Secondary Infection: air-borne sporangia.
Favourable Conditions
 Relative humidity 100 %
 Optimum temperature 21-23 0 C
 Light drizzling
 Cool weather

25. Management
 Destroyal of affected plants by burning before oospore formation, reduce
the inoculum potential
 Crop rotation with other crops like pulses and oilseeds.
 Grow Tolerant varieties like CSH 2, CSV 5, SPV 101, 165 and 190.
 Seed Treatment with Metalaxyl (Apron 35 SD) @4g/kg seed
 Spray Metalaxyl (Ridomyl MZ) @0.2% or Mancozeb @0.25%

27. Phanerogamic parasite (S t r i g a o r W i t c h W e e d )
Striga asiatica , Striga densiflora
Symptoms
 Sorghum root exudates stimulate the seeds of the parasite to germinate.
 Parasite attach to the Host root by haustoria and grow below the soil surface and produce
underground stems and roots for about 1-2 months.
 The parasite grows faster and appears at the base of the plant.
 Severe infestation causes Yellowing and wilting of the host leaves.
Stunted growth and may die prior to
seed setting, if the infection occurs early
Disease cycle
Primary Infection : Seeds present in the Soil.
Secondary Infection :
Favourable Conditions
 Soil temperature 350 C
 soil moisture 30 %

28. 1. Hand weeding of the parasites before flowering.
2. Crop rotation with cowpea, groundnut and sunflower.
3. Mixing of Ethrel with soil triggers germination of Striga in the absence of host.
4. Spray Fernoxone (sodium salt of 2,4-D) or Agroxone (MCPA) at 450g/500
liters of water or Praquat @ 1 kg/ha.
5. 1% Tetrachloro dimethyl phenoxy acetate can be used for instant killing of
Striga, if water is in scarce.
Tetrachloro dimethyl phenoxy acetate