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Bacteria, GRACILICUTES, EUBACTERIALES, ENTEROBACTERIACEAE .
Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images
[R]Description
Mainly affects the pluriannual crops.
The parts of the affected plants above the ground wilt and dry out progressively starting from the outermost leaves.
The root system and the collar are attacked by rot which first causes browning of the pith and, in the end, decay of all the tissues : at this point they emmanate a fetid smell.
As the epidemic progresses plants die on certain spots in the field and large "blanks" occur in the crop.
[R]Biology
This cosmopolitan species can survive in the soil freely or on decaying infected debris or even in the pupa of .
Infection occurs through wounds.
After reproduction in the parenchymal tissues or in the intracellular space, the bacteria produce pectolytic enzymes and to a lesser extent cellulolytic enzymes : the former cause the rupture of the middle lamella and consequently the desagregation of the organs and tissues (soft rot).
These become hosts for other proteolytic microorganisms which cause the fetid smell.
[R]Epidemiology
The irrigation water is the main carrier of inoculum from plant to plant and from field to field. The disease mainly occurs in heavy unaired land, rich in humus and the symptoms show during the warm months (august-october) with an optimum temperature 30 - 35 °C. for pathogenic development.
[R]Treatement
Reduce the frequency of artichoke culture (maximum biannual).
Appropriate rotations to avoid the too frequent occurence of the crop in the same field.
Use healthy shoots from uninfected crops or treated with coppery products.
[R]Possible misleading
"Collar rot" caused by Sclerotinia sclerotiorum , Sclerotium rolfsii and Rhizoctonia solani .
HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.
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