Cucurbits Bacterial Wilt

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 C ausal 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. P umpkins 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 M arch 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, 9 th edition.