2. DISEASES OF SESAMUM AND
THEIR MANAGEMENT
PAT 507: Diseases of field crops (2+1)
Submitted by:- Jayant J P
Dept. of agricultural Entomology.
Submitted to:-Dr. Savita A S
Dept. of Plant pathology.
3. • One of the oldest oil seed crop and is under
cultivation from ancient times.
• India contributes the highest sesame acreage
of above 17.73 lakh hectare[1st] and
production 8 lakh tones[1st] and productivity of
445kg/hectare[3rd].
• It is also known as generally, till, popularly as
“Queen of Oilseeds” due to its high degree of
resistance to oxidation and rancidity.
SESAMUM
Sesamum indicum L.
FAMILY:- Pedaliaceae
4. • India is a major exporters to number of
countries and has earned the foreign exchange
of Rs 2800 crore.
• Sesame has one of the highest oil content
(50-60%)of any oil seed crop and contains high
amount of PUFA, mainly linoleic acid(37-
47%).
• Sesame seeds are used in hindu culture as a
“symbol of immortality” and known as “butler
of middle east”.
6. PHYLLODY
C.O:- Phytoplasma
• It is a serious and wide spread disease of sesame
and caused by a pleomorphic mycoplasma–like
organism (MLOs) which is now called as
Phytoplasma.
• The phyllody is transmitted by the insect vector
Orosius albicinctus[Leaf hopper].
• The disease has been recorded in India, Iran,
Israel, Burma, Sudan, Nigeria, Tanzania, Pakistan,
Ethopia, Thailand, Turkey, Uganda, and Mexico.
7. SYMPTOMS
• The infected plant is characterized by
transformation of all floral parts into green
leafy structures followed by abundant vein
clearing in different flower parts.
• In severe infection, the entire inflorescence is
replaced by short twisted leaves closely
arranged on a stem with short internodes and
abundant abnormal branches bend down.
• Finally, plants look like witches broom.
8.
9. DISEASE CYCLE
• The pathogen has a wide host range and survives on alternate
hosts like Brassica campestris var. toria,B. rapa, Cicer
arietinum,Crotalaria sp., Trifolium sp., Arachis hypogaea which
serve as source of inoculum.
• The disease is transmitted by Leaf hopper, Orosius albicinctus.
• Optimum acquisition period of vector is 3-4 days and inoculation
feeding period is 30 minutes.
• The incubation period of the pathogen in leaf hoppers may be 15-
63 days in sesame. Nymphs are incapable of transmitting the
phytoplasma.
• Vector population is more during summer and less during winter
months.
11. MANAGEMENT
• Remove and destroy infected plants.
• Intercropping of Sesame+Pigeonpea (6:1) is helpful for the
management of phyllody.
• Use of tolerant varieties :-TKG 21, RT-125 and RT-103.
To control vector……
• Spraying of neem oil @10ml/l for vector (leaf hopper) control is
helpful in managing the phyllody.
• Seed treatment with imidacloprid or carbosulfan protects the crop
from all sucking pests including leaf hoppers for about a month.
• Soil treatment with Phorate 10 G @ 11 kg/ha at the time of
sowing.
• Spray Dimethoate 30 EC 1ml/liter or Spinosad 0.5ml/lit.
13. SYMPTOMS
• The disease symptom starts as yellowing of lower
leaves, followed by drooping and defoliation.
• The symptoms were produced at ground level,
stem becomes black, which extends upward
rupturing the stem and black dots appear on the
infected stem.
• The roots will become brittle.
• In disease infected plants, black capsules are seen
which open prematurely exposing shriveled seed.
15. ETIOLOGY
• The pathogen produces dark brown, septate
mycelium showing constrictions at the hyphal
junctions.
• The sclerotia are minute, dark black and 110-130µm
in diameter.
• The conidia are hyaline, elliptical and single celled.
Epidemiology
• Day temperature of 30˚C and above
• Prolonged drought followed by copious
irrigation.
16. DISEASE CYCLE
• The fungus remains dormant as sclerotia in
soil as well as in infected plant debris in
soil.
• The fungus primarily spreads through
infected seeds which carry sclerotia and
pycnidia. The fungus also spreads through
soil-borne sclerotia.
• The secondary spread is through the conidia
transmitted by wind and rain water.
17. MANAGEMENT
• Field sanitation and Soil solarisation.
• Use of tolerant varieties - RT-46, RT0125, MT-
75, TKG-22 and Nirmala.
• Treat the seeds with Trichoderma viridae at
5g/kg.
• Seed treatment with carbendazim + thiram
(1:1) at 2g/kg seed.
• Spot drench with Carbendazim at 1.0 g/litre.
19. SYMPTOMS
• It appears as small, angular brown leaf spot 5-
15 mm in diameter on both leaf surfaces.
• Under favorable conditions, the disease
spreads to leaf petiole, stem and capsules
producing linear dark coloured lesions.
• Extensive infection of foliage and capsule
leads to defoliation and damage of sesame
capsule and yield losses may range from 22 to
53% .
20.
21. • ETIOLOGY:-
• Conidia are elongated, 7-10 septate, hyaline to light
yellow, broad at the base and tapering towards the apex.
• EPIDEMEOLOGY:-
• Humid conditions usually late spring and summer and
dampness favours the disease.
DISEASE CYCLE:-The fungus is externally and
internally seed-borne. The fungus also survives in plant
debris. Primary sources of infection are seeds and infected
debris.
•The secondary spread is through wind-borne conidia.
22. MANAGEMENT
• Field sanitation.
• Early planting (immediately after onset of
monsoon) .
• Intercropping of Sesame+Pearl millet (3:1) is
helpful for controlling Cercospora disease.
• Treat the seeds with Carbendazin or Thiram at
2g/kg.
• Spray with Topsin-M (0.1%), Mancozeb
(0.25%),Difenoconazole (0.1%) ,Carbindazim
50wp+Mancozeb
24. SYMPTOMS
• It appears at vegetative stage to capsule formation stage as
small patches of white powdery mass on upper side and
occasionally on lower surface of leaves.
• Defoliation of severely infected plant occurs before
maturity.
• The infection may be seen on the flowers and young
capsules, leading to premature shedding.
25. ETIOLOGY:-
•Fruiting body is cleistothesia with many number of asci.
•Asexual spores are oidia which are ectophytic in nature.
EPIDEMEOLOGY:-
• Dry humid weather and Low relative humidity.
Disease Cycle:-
•The Pathogen is an obligate parasite and disease spreads through
conidia in the infected plant debris in soil.
•The secondary spread is through wind-borne conidia.
26. MANAGEMENT
• Remove the infected plant debris and destroy.
• Spray Carbendazim 0.1% , Wettable sulphur
0.3%, Hexaconazole 0.2%.
29. SYMPTOMS
• It affects the plants at all stages and symptoms
produce are small dark brown water soaked,
round to irregular lesions with concentric rings
varying from 1-8 mm in diameter.
• In severe infections several spots involving major
portions of leaf blade and later leaf drop off from
the plants.
• Dark brown lesions can also be seen on petioles,
stem and capsules. Infection of capsules results in
premature splitting with shriveled seeds.
30.
31. ETIOLOGY:-
• The conidia are light olive coloured with
transverse and longitudinal septa.
• These are around 3-5 septate and conidia are
borne in chain over short conidiophore.
EPIDEMEOLOGY:-
• Low temperature (20-25°C),
• High relative humidity
• Cloudy weather.
Disease Cycle
• The fungus is seed-borne and also soil-borne as it
remains dormant in the infected plant debris.
32. MANAGEMENT
• Field sanitation.
• Treat the seeds with thiram or Carbendazim at
2g/kg.
• Spray Mancozeb at 2gm/lit[2kg/ha] or
Iprodion 1L/ha.
33. Bacterial Blight
C.O:- Xanthomonas Compestris pv. sesami
SYMPTOMS
• Initially water-soaked spots appear on the undersurface of
the leaf and then on the upper surface. They increase in size,
become angular and restricted by veins and dark brown in
color.
• Several spots coalesce together forming irregular brown
patches and cause drying of leaves.
• The lesions may also occur on petioles and stem.
34. ETIOLOGY:-The bacterium is a Gram negative, rod shaped with a
monotrichous flagellum.
Disease cycle
The bacterium survives in the infected plant debris and in seeds. The
secondary spread is by rain water.
35. MANAGEMENT
• Crop rotation.
• Use resistant variety like T-58
• Early planting i.e. immediately after onset of monsoon.
• Destruction of crop residues.
• 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.
36. Bacterial leaf spot
C.O:-Pseudomonas syringe pv sesame
SYMPTOMS
• The disease appears as water-soaked yellow
specks on the upper surface of the leaves.
• They enlarge and become angular as resticted
by veins and veinlets.
• The colour of spot may be dark brown with
shiny oozes of bacterial masses.
37. ETIOLOGY
The bacterium is gram negative aerobic rod with one or
more polar flagella.
Disease cycle
The bacterium remains viable in the infected plant tissues. It
is internally seedborne and secondary spread through rain
splash and storms.
38. MANAGEMENT
• Keep the field free of infected plant debris.
• Spray with Streptomycin sulphate or
oxytetracycline hydrochloride or streptocyclin
at 100g/ha.
41. References:-
• Status of sesame diseases and their integrated
management using indigenous practices :
KN Gupta, KR Naik and Rajni Bisen
{International Journal of Chemical Studies 2018; 6(2):
1945-1952}
• Diseases of field crops and their management
-Dr. p Kishore varma.
• Wikipedia
• http://ecoursesonline.iasri.res.in/Courses/Diseases%20of
%20Field%20Crops%20and%20Their%20Management/P
ATH%20272/Start%20to%20read%20the%20Course.htm
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