Cucurbits Bacterial Wikt

1. CUCURBITS BACTERIAL WILT
STUDENT COURSE TEACHER,
P.PRIYA, Dr.S.PARTHASARTHY,
2015021098. Asst. Professor (Plant Pathology)
COLLEGE OF AGRICULTURAL TECHNOLOGY
(Affiliated to Tamil Nadu Agricultural University , Coimbatore
Kullapuram (po),via vaigai Dam , Theni -625 562

2. BACTERIAL WILT
PATHOGEN
Causal organism: Erwinia tracheiphila
DISTRIBUTION
It is widely spread in North America,
Europe, Asia, Africa.

3. PATHOGEN
Bacterium, Gram-negative, straight rod,
motile, peritrichous flagella.
SYMPTOMS
Bacterial wilt is the disease of vascular tissue.
First appear on a single leaf which suddenly
wilts and becomes dull green.

4. Leaves eventually yellow and brown at margins,
completely wither and die.
Wilt progression varies by crop.
Cucumbers and melons wilt and die rapidly.
Pumpkins take up to two weeks to wilt
completely.
 Summer squash may continue to produce for
several weeks even when infected.

5. Wilt progress down to the vine untill the entire
vine wilts or dies.
Striped or spotted cucumber beetles will be
present in the garden.
If infected vines are cut close to the crown of the
plants and the cross sections pressed together,
thread like strands of bacterial ooze are visible
when the two halves are gently pulled apart again.

6. @apsnet.org

7. Viscous bacterial mass
@Farms.com

8. Taxonomic position
Kingdom :Bacteria
Phylum :Proteobacteria
Class :Gamma Proteobacteria
Order :Enterobacteriales
Family :Enterobacteriaceae
Genus :Erwinia
Species : Erwinia tracheiphila

9. MODE OF SPREAD
This is transmitted through insect vector, Stripped
cucumber beetle (Acalymma vittatum) and spotted
cucumber beetles (Diobrotica undecimpunctata).
The beetles acquire the pathogen by feeding on
infected plants, then carry the bacteria in their
digestive tracks.

10. The disease may be spread to susceptible
plants through feeding wounds, by way of
infected mouthparts or frass.
The bacteria is capable of overwintering in the
guts of its insect vector.

11. Striped and spotted cucumber beetles
@ www.tenthacrefarm.com

12. @studylib.net

13. FAVOURABLE CONDITION
A year with good winter snow cover followed
by a March and April could be expected to
increase the number of beetles and therefore
increase the incidence of bacterial wilt.

14. MANAGEMENT:
Protect plants with netting to prevent cucumber
beetles from feeding.
Spray carbaryl, Malathion, or roteone insecticide
or combination product are registered to treat
cucumber beetles.
Roguing wilted plants and the use of trap crops
have been suggested.

15. Growing tolerant varieties like butternut or
acorn squash and saladin or country Fair 83
cucumbers. No muskmelons varieties are
known to be tolerant to bacterial wilt.

16. REFERENCE:
Gupta V.K and Y.S Paul, 2008, Diseases of
Vegetable Crops, published by Kalyani
Publishers, second edition.
R.S. Singh, Plant Diseases, Oxford and IBH
publishing co. pvt. ltd, New Delhi, 9th edition.