|
|
How to Manage Pests
UC Pest Management Guidelines
Onion and Garlic
Bacterial Soft Rot
Pathogens: Erwinia carotovora ssp. carotovora,
E. chrysanthemi, Pseudomonas gladioli, and Enterobacter cloacae
(Reviewed 1/07,
updated 1/07)
In this Guideline:
|
|
|
Bacterial soft rots are characterized by softening and water soaking
of one or more of the inner fleshy scales of the bulb. Affected tissue is
yellow initially, turning brown as the disease progresses lengthwise in the
bulb. The neck of infected bulbs may be soft when pressed. These organisms
generally appear just before or at the time of harvest or in storage.
Bacterial soft rots are primarily a problem on onions, but not
garlic. Free water is essential for entry and spread of the bacteria. Wounds
and senescent leaves are the means by which bacteria gain entrance into the
bulb. The pathogens are soilborne and may be spread in irrigation water.
Cultural Control
Avoid overhead irrigation once onions start to bulb
(bulbing occurs about the time the bulb is twice the diameter of the neck).
Harvest only after onion tops are well matured. Provide for quick drying
following topping, especially if temperatures are high.
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Onion and Garlic
UC ANR Publication 3453
Diseases
R. M. Davis, Plant Pathology, UC Davis
B. J. Aegerter, UC Cooperative Extension, San Joaquin Co.
Acknowledgment for contributions to the diseases section:
F. F. Laemmlen, UC Cooperative Extension, Santa Barbara/San Luis Obispo counties
R. E. Voss, Vegetable Crops, UC Davis
Top of page
|
