How to Manage Pests

UC Pest Management Guidelines

SYMPTOMS

Symptoms of garlic mosaic include mild to strong mosaic, chlorotic mottling, striping, and streaking of leaves. Symptoms are usually more pronounced in young leaves. Infected plants are stunted and bulb size is reduced.

COMMENTS ON THE DISEASE

Because garlic is vegetatively propagated, several viruses are commonly present in all garlic. The label "garlic mosaic" has been applied to a number of different viruses in different countries and this has caused some confusion. However, there is a trend toward referring to garlic mosaic as a disease caused by one or more viruses belonging to the potyvirus group (onion yellow dwarf virus, leek yellow stripe virus, and several others). In addition to being spread by vegetative reproduction, these potyviruses can also be transmitted by various aphids.

MANAGEMENT

Virus-free stocks should be produced from meristem tip culture and multiplied in areas free of commercial garlic to prevent reinfection by insects. Use of such "virus-free" stock can result in substantially higher yield.

PUBLICATION

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

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