Systematic position, Symptoms, IDM

1. Blackgram leaf crinkle virus
and
Blackgram leaf curl virus
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University, Coimbatore-3)
Kullapuram (Po),ViaVaigai Dam, Theni-625 562
STUDENT
Miss. KAVIYA R
ID. No. 2015021058
COURSE TEACHER
Dr. PARTHASARATHY S
Asst. Professor (Plant Pathology)

2. Blackgram leaf crinkle virus
 Blackgram leaf crinkle virus causes Blackgram leaf
crinkle disease/Urdbean leaf crinkle disease.
 Urdbean (Vigna mungo L. Hepper) is more susceptible than
other pulses to leaf crinkle disease.

3. History:
First reported in Vigna mungo from the Pantnagar District,
Nainital, India by Sharad Chandra J Kolte and Dr.Yeshwant
Laxman Nene (1972).
They found that the first recognizable symptoms, under field
conditions, usually appear 3 weeks after sowing of black gram
with seedborne infection.

4. .
Geographical distribution :
Spreads in India
©Plantwise.org

5. Systematic position:
Group : II
Order : (+) ss DNA viruses
Family : Geminiviridae
Genus : Begomovirus
Species : Urdbean leaf crinkle virus (ULCV)

6. Significance :
Urdbean leaf crinkle disease (ULCD) is an economically
significant widespread and devastating disease
resulting in extreme crinkling, puckering and rugosity of
leaves.

7. • It inflicts heavy yield losses annually in major Urdbean-
producing countries of the world.
• The loss in seed yield in ULCD-affected Urdbean crop ranges
from 35 to 81%, which is dependent upon type of genotype
location and infection time.

8. Host plants / species affected:
o Vigna mungo (Black gram)
o Cajanus cajan (Pigeon pea)
o Cucumis sativus (Cucumber)
o Lablab purpureus (Hyacinth bean)
o Phaseolus lathyroides (Phasey bean)
o Phaseolus vulgaris (Common bean)
o Ricinus communis (Castor bean)
o Vigna aconitifolia (Moth beans)
o Vigna radiata (Mung bean)
o Vigna unguiculata (Cowpea)

9. Symptoms/signs
 Inflorescence - twisting and distortion
 Leaves - abnormal forms
 Whole plant - dwarfing

10. s The disease usually attacks black gram in all seasons.
 Characterized by enlargement of leaves followed by crinkled
surface of leaf lamina.
 The crinkling is more on younger leaves.
 Flowering is delayed by 8-10 days.
 Inflorescence turns bushy in appearance.
 Pod setting is curtailed which decreases the yield drastically.

11. Blackgram leaf crinkle virus symptom
© AGRIORISSA
Vector : whitefly

12. Survival & Favourable Conditions
 The virus is seed transmitted.
 Whiteflies, Aphids and Henosepilachna beetles also transmit
the disease.
 The virus is also transmitted through sap inoculation,
grafting.

13. INTEGRATED DISEASE MANAGEMENT:
Cultural Control:
 The crop must be sown timely.
 The spacing between the lines should be maintained at 30 to
40 cm.
 Only certified seeds should be used for sowing.

14. In endemic areas only tolerant and resistant varieties should be
used.
 Weeds plants should be rouged out at their inception.
 Insect, fungal and nematode vectors should be controlled using
suitable pesticides.

15.  Control white fly as it spreads the virus.
 Grow resistant varieties like ADT-3.
 Removal and quick burning of the infected plant.

16. Chemical Control:
 Seed-borne infection can be eliminated by hot water treatment
of seed at 55°C for 30 minutes.
 Spraying insecticides 3 weeks after sowing control pests.

17. Blackgram leaf curl virus
Systematic position:
Group : V (-) ss RNA virus
Order : Mononegavirales
Family : Bunyaviridae
Genus : Tospoviridae
Species : Tomato spotted wilt virus (TSWV)

18. Damage :
 A potential killer of black gram plants, more severe in Kharif
season.
 The earliest symptoms appear on youngest leaves as chlorosis
around lateral veins and its branches near the margin.

19. The leaves show curling of margin downwards.
Some of the leaves show twisting.
The veins show reddish brown discolouration on the under
surface which also extends to the petiole.

20.  Plants showing symptoms within 5 weeks after sowing
invariably remain stunted and majority of these die due to
top necrosis within a week or two.
 Plants infected in late stages of growth do not show severe
curling and twisting of the leaves but show conspicuous
venial chlorosis any where on the leaf lamina.

21. Blackgram leaf curl virus – symptom
© ©AGRIORISSA
Vector: Scirtothrips dorsalis

22. Mode of spread:
The disease develops in the fields mainly through seed or
rubbing of diseased leaves with the healthy ones.
INTEGRATED DISEASE MANAGEMENT:
Cultural Control:
 Timely sowing.
 Complete field and crop sanitation.
 Take control measures for thrips.

23. Chemical Control:
The virus is transmitted by thrips - Scirtothrips dorsalis, and
controlling thrips by spraying 1 g Acephate or 2 ml
Dimethoate per litre.

24. REFERENCES:
 AGRIORISSA – Blackgram (Urad dal) Diseases.
 Beniwal.S.P.S and Y.L. Nene, 1983, Plant Viruses Online -
Urdbean leaf crinkle virus.