Integrated Pest Management

 Alternaria leaf spot

Causal Organism

Alternaria sesami

Damage

• The pathogen attacks all parts of the plant at all stages.
• Small, dark brown water soaked, round to irregular lesions, with concentric rings, 1-8 mm in diameter appear on the leaves and under excessive atmospheric and soil humidity the spot increases in size and number.
• The lesions may also appear on the midrib and veins of the leaves.
• Milder attacks cause only defoliation, in severe cases the plant may die.

Survival & Favourable Conditions

• The pathogen is seed borne.
• Temperature of 20-30^o C and high humid conditions favour the disease.

Cultural Control

• Grow resistant/tolerant variety like Krishna.
• Destruction of crop residues and weeds.
• Early planting i.e. immediately after onset of monsoon.
• Follow intercropping system of sesamum + sunflower (3:1).

Chemical Control

• Treat the seed with thiram (0.15%) + Bavistin (0.05%) in 1:1 ratio.
• Three sprays Topsin M(0.1%) as and when disease appears, at 15 days interval.

Bacterial blight

Causal Organism

Xanthomonas campestris pv. sesami

Damage

• Plants of all stage is affected.
• Water soaked, small and irregular spots are formed on the leaves which later increases and turn brown, under favourable conditions.
• Leaves become dry and brittle, severely infected leaves defoliate.
• Later, the spots are formed on the twigs, which bear poor capsules.

Survival & Favourable Conditions

• Pathogen is seed borne and spread through rain water.
• High temperature and humidity favour disease incidence.

Cultural Control

• Crop rotation.
• Use resistant variety like T-58
• Early planting i.e. immediately after onset of monsoon.

Mechanical Control

• Destruction of crop residues.
• Seed treatment with hot water at 52 ^o C for 10 minutes.

Chemical Control

• Steep the seed in Agrimycin-100 (250 ppm) or Streptocycline suspension (0.05%) for 30 minutes.
• Foliar spray of Streptocycline (500 ppm) as soon as symptoms are noticed.
• Continue two more sprays at 15 days interval if necessary.

Bacterial leaf spot

Causal Organism

Pseudomonas syringae pv. sesami

Damage

• Light brown angular spots with dark purple margin appear in the leaf veins.
• Defoliation and death of plant may occur in severe leave and stem infection.
• Sunken and shiny spots are appeared on the capsules.
• Early capsule infection render them black and seedless.

Survival & Favourable Conditions

• The pathogen is seed borne.
• High temperature, rainfall and persistent humidity favours the disease.

Cultural Control

• Use white seeded early varieties.
• Crop rotation.
• Use resistant varieties.

Mechanical Control

• Destruction of crop residues.
• Seed treatment with hot water at 52^o C for 10 minutes

Chemical Control

• Steep the seed in Agrimycin-100 (250 ppm) or Streptocycline suspension (0.05%) for 30 minutes.
• Foliar spray of Streptocycline (500 ppm) as soon as symptoms are noticed.
• Continue two more sprays at 15 days interval if necessary.

Cercospora leaf spot / White spot

Causal Organism

Cercospora sesami, C. sesamicola

Damage

• Disease appears as small, angular brown leaf spots of 3 mm diameter with gray centre and dark margin delimited by veins.
• In severity of the disease defoliation occurs.
• Under favourable conditions, the disease spreads to leaf petiole, stem and capsules producing linear dark coloured deep seated
  lesions.

Survival & Favourable Conditions

• The pathogen survives on infected seed and also in plant debris in soil.
• High temperature favour the disease growth, hence most destructive in summer months.

Cultural Control

• Grow resistant/tolerant variety like TKG-21.
• Early planting i.e. immediately after onset of monsoon.
• Follow intercropping system of sesamum + pearl millet (3:1).

Mechanical Control

• Destruction of plant debris.

Chemical Control

• Treat the seed with Thiram (0.15%) + Bavistin (0.05%) in 1:1 ratio.
• Three sprays Topsin M(0.1%) or Zineb (0.25%) or mancozeb (0.25 %)as and when disease appears, at 15 days interval.

Corynespora blight

Causal Organism

Corynespora cassiicola

Damage

• On leaves purple brown specks which develop into large spots.
• Infected leaves curl and defoliate.
• On stem, purple brown elongated lesions appears.
• On capsule circular to elongated sunken spots appears.

Survival & Favourable Conditions

• The pathogen is seed and soil borne
• It survives in soil in infected crop residues.

Cultural Control

• Destruction of weed and crop residues.
• Field sanitation.
• Early planting i.e. immidiately after onset of monsoon.
• Follow intercropping system of sesamum+pearl millet (3:1).

Chemical Control

• Treat the seed with Thiram (0.15%)+Bavistin (0.05%) in 1:1 ratio.
• Three sprays topsin M(0.1%) or mancozeb (0.25%) as and when disease appears, at 15 days interval.

Damping off / Root Rot

Causal Organism

Macrophomina phaseolina

Damage

• The fungus attacks young seedling, their stem become water soaked soft and incapable of supporting the seedling which falls over and dies.
• On older seedlings elongated brownish black lesions appear which increase in length and width girdling the stem and plant dies.

Survival & Favourable Conditions

• The fungus survives in the soil and on infected seeds and on weed hosts.
• Favoured by cold and wet soil.

Cultural Control

• Crop rotation.
• Provide good drainage.
• Late planting.
• Inter cropping with moth bean (1:1 or 1:2).

Mechanical Control

• Destruction of diseased plants.

Chemical Control

• Seed treatment with Thiram 75 SD (0.15%)+Bavistin (0.05%) 1:1 or Thiram 75 SD (0.3%).
• On appearance of the disease, drench soil with Thiram + Bavistin (1:1) along with diseased plants at 7 days interval.

Phytophthora blight

Causal Organism

Phytophthora parasitica var. sesami

Damage

• Disease can attack at all stages of the plant.
• Initial symptom is water soaked spots on leaves and stems.
• The spots are chestnut brown in the beginning later turn to black.
• Premature leaf fall occurs.
• In humid weather, severity of disease increases, main root is affected, diseased plants are easily pulled out leaving lets and cortex behind, and produce shriveled seeds and gives blighted
  appearance.

Survival & Favourable Conditions

• The pathogen survives in soil and seed borne.
• Heavy rains for 2 weeks and >90% relative humidity favour disease development.
• The disease is severe in the area of heavy soil with high rainfall.

Cultural Control

• Follow two year crop rotation.
• Deep summer ploughing.
• Provide good drainage.
• Late planting
• Use resistant tolerant varieties like TKG-22, TKG-55 and JTS-8.
• Intercropping system, sesamum+pearl millet(3:1) should be followed.

Mechanical Control

• Destruction of crop debris.
• Rougue out diseased plants.

Biological Control

• Soil amendment with biological control agent like Trichoderma harzianum and Trichoderma viride or seed treatment with T. Harzianum/ T. viride / Bacillus subtilis (0.4%)

Chemical Control

• Seed treatment before sowing with Apron 35 SD(0.3%) or Thiram (0.3%) .
• For root/stem infection, drench soil 2-3 times with Ridomil Mz (0.25%) along with diseased plants at 7 days interval.
• Spray crop 3 times with Ridomil Mz (0.25%) or copper oxychloride (0.25%) at an interval of 10 days from the initiation of disease.

Powdery mildew

Causal Organism

Oidium sp. Sphaerotheca fudiginia, Leveillula

Damage

• Small cottony spots appear on the infected leaves which gradually spread on the lamina.
• Defoliation of severely infected plant occurs before maturity.

Survival & Favourable Conditions

• This has a wide host range.
• Disease spreads under day season and survive on weeds/alternate hosts.

Cultural Control

• Field sanitation.
• Destruction of crop residues.
• Early planting i.e. immediately after onset of monsoon.
• Follow intercropping system of sesamum + pearl millet (3:1).
• Use resistant variety RT-127

Mechanical Control

• Destruction of crop residues and alternate hosts.

Chemical Control

• Foliar spray (2 to 3) of wettable sulphur (0.2%) as and when disease appears, at 10 days interval.

Sesamum phyllody

Causal Organism

Phytoplasma like organism

Damage

• All floral parts are transformed into green leafy structures followed by abundant vein clearing in different flower parts.
• In severe infection, the entire inflorescences is replaced by short twisted leaves closely arranged on a stem with short internodes, abundant abnormal branches bend down.
• Finally, plants look like witches broom.
• If capsules are formed on lower portion of plant they do not yield quality seeds.

Survival & Favourable Conditions

• The disease is transmitted through jassids and MLO survives in leaf hopper throughout its life.

Cultural Control

• Delay in planting of sesamum about 3 weeks after onset of monsoon.
• Use intercropping system, sesamum + pigeon pea (1:1).
• Use resistant varieties.
• Provide plant spacing.

Mechanical Control

• Destruction of diseased plants.

Chemical Control

• Soil application of Phorate at the rate of 10 kg/ha.
• Three spray of Dimethoate (0.03%) at 30,40 and 60 days after sowing.

Stem and root rot

Causal Organism

Rhizoctonia bataticola (Macrophomina phaseolina)

Damage

• The affected plants show wilting.
• At ground level stem becomes black which extends upward rupturing the stem.
• Black dots appear on the infected stem which are the pycnidia of the fungus.
• If wilted plant is uprooted, black coloured roots are observed having sclerotia of the fungus and looks as if charcoal is sprinkled on the root.
• The roots become brittle.
• In diseased plants black pods are seen which open prematurely exposing shriveled and discoloured seeds.

Survival & Favourable Conditions

• The Pathogen survives in seed and soil borne.
• High soil temperatures and stress conditions favour the development of the pathogen.

Cultural Control

• Deep summer ploughing.
• Provide good drainage.
• Late planting.
• Do crop rotation or change the field after every two years.
• Follow intercropping system sesamum + mothbean 1:1 or 2:1 ratio.
• Whenever necessary, irrigate field every two weeks to avoid stress condition.
• Use resistant varieties.

Mechanical Control

• Destruction of crop residues.

Biological Control

• Soil incorporation of biological control agents like Trichoderma harzianum, Trichoderma viride.
• Treat the seed with T. viride or T. harzianum or Bacillus subtilis (0.4%)

Chemical Control

• Seed treatment with Thiram 75 SD (0.15%)+Bavistin (0.05%) 1:1 or Thiram 75 SD (0.3%).
• On appearance of the disease, drench soil with Thiram + Bavistin (1:1) along with diseased plants at 7 days interval.

Wilt

Causal Organism

Fusarium oxysporum f.sp.sesami

Damage

• The plant gets infected at any stage of crop development.
• Symptoms are first visible in the lower leaves and then it progresses upwards.
• Yellowing, drooping and desiccation of leaves occur.
• In severe case, entire plant gets defoliated, bends down and ultimately dries up.
• Vascular bundles turn brown starting from root and gets extended up to tip.
• Root do not rot.

Survival & Favourable Conditions

• The pathogen is seed and soil borne.
• High soil temperature favours the disease.

Cultural Control

• Use resistant varieties like JT-7, N-32, MB-12
• Crop rotation

Mechanical Control

• Destruction of wilted plants.

Biological Control

• Conserve biological control agents like Trichoderma harzianum, Trichoderma viride

Chemical Control

• Seed treatment with thiram (0.3%) or carbendazim (0.15%)