DRY ROOT ROT ALTERNARIA LEAF BLIGHT POWDERY MILDEW SESAME PHYLLODY ALONG WITH THEIR INTEGRATED DISEASE MANAGEMENT

1. SESAME DISEASES AND
THEIR MANAGEMENT
Prepared by
KAVIYARASAN.G
Faculty of Agriculture
Annamalai University.

3. DRY ROOT ROT
Pathogen : Macrophomina phaseolina Tassi(gold)
• Symptoms:
• The symptom starts as yellowing of lower leaves, followed by
drooping and defoliation.
• Affected plants can be easily pulled out leaving the rotten root
portion in the soil.
• The stem portion near the ground level shows dark brown lesions and
bark at the collar region shows shredding.

5. ALTERNARIA LEAF BLIGHT
Pathogen : Alternaria sesami (Kawamura) Mohanty and
Behera
• Symptoms: Symptoms of the disease appear mainly on leaf blades as
small, brown, round-to-irregular spots, varying from 1 to 8 mm in
diameter.
• The spots later become larger and darker with concentric rings with
brown lines inside the spots on the upper surface.
• Dark brown lesions can be seen on the entire length of the stem. The
lesions also occur on the midrib and even on veins of leaves.
• Infection of capsules results in premature splitting with shrivelled
seeds.

7. POWDERY MILDEW
Pathogen : Oidium erysiphoides (Fr.), Sphaerotheca
fuliginea(schlecht)Pollachi , Leveillula taurica (Lav.) Trnaud
• Symptoms: Symptoms of the disease start as small whitish spots on
the upper surface of the leaves.
• The spots coalesce to form a single spot, finally covering the entire leaf
surface with dirty white fungal growth.
• Generally, the mildew is confined to the upper surface of the leaves.
Defoliation of severely infected plant occurs before maturity.
• Inn severe cases, the infection may be seen on the flowers and young
capsules, leading to premature shedding.

9. PHYLLODY
Pathogen : Candidatus phytoplasma asteris
• Symptoms: A plant infected in its early growth remains stunted to about
two-thirds of a normal plant and the entire plant may be affected.
• The entire inflorescence is replaced by a growth consisting of short, twisted
leaves closely arranged on a stem with short internodes.
• However, when infection takes place at later stages, normal capsules are
formed on the lower portion of the plants and phylloid flowers are present
on the tops of the main branches and on the new shoots that are produced
from the lower portions.
• The most characteristic symptom of the disease is transformation of flower
parts into green leaflike structures.

12. INTEGRATED DISEASE MANAGEMENT

13. Common cultural practices:
 Deep ploughing is to be done on summer during the months of May and June.
 Avoid planting overlapping crops in adjacent area. Adopt crop rotation, bhendi-sesame-maize,
maize-sesame-maize and sesame-ragi-brinjal.
 Raising African marigold nursery 15 days prior to sowing.
 Grow only recommended varieties.
 Sow early in the season.
 Bower system (maintain gapping) of cropping reduces the powdery mildew disease incidence.
 Sow in rows at optimum depths under proper moisture conditions for better establishment.
 Provide irrigation at critical stages of the crop.
 Avoid water logging.
 Avoid water stress during flowering stage.
 Use NPK fertilizers as per the soil test recommendation.
 Use micronutrient mixture after sowing based on test recommendations.

14. Common mechanical practices:
 Destroy crop debris.
 Remove alternate weed hosts.
 Rogue out the diseased plants periodically.
Common biological practices:
 Treat the seeds with Trichoderma viride at 4 g/kg or Pseudomonas fluorescens at 10 g/kg.
SUCH SEEDS SHOULD NOT BE TREATED WITH FUNGICIDES.
 Soil amendment with Trichoderma-fortified farm yard manure at 150 kg/ha at sowing time is
helpful in reducing the incidence of the soil borne diseases.
 Intercropping with greengram or redgram or blackgram or mothbean or maize or cumbu
minimizes the incidence of major diseases.
 Spray neem oil at 5 ml/lit for leaf hopper control.
 Apply neem cake at 200 kg/ha for leaf hopper control.

15. Common chemical practices:
 Apply only recommended fungicides at recommended dose, proper time, as appropriate
spray solution with standard equipment.
 Treat the seeds with carbendazim at 2 g/kg of seed before sowing.
 Two sprays of mancozeb at 2 kg/ha, first spray being given at flower initiation stage and the
second at pod formation stage, for the control of leaf spot diseases.
 The crop can be protected from the powdery mildews by one or two sprays of wettable
sulfur at 2.5 kg/ha or karathane at 1 lit/ha or sulfur dust at 20 kg/ha.
 At the time of sowing, soil may be treated with phorate at 11 kg/ha or aldicarb at 25 kg/ha
for leafhopper control.
 Sprays tetracycline at 500 ppm at the flower initiation stage have proved to be effective
against phyllody disease.
 Streptocycline 0.025% seed treatment for 2 h followed by three sprays at 10-day interval of
streptocycline plus copper oxychloride effectively control the bacterial disease.