University of California

Omphalia root rot of the date palm


Donald E. Bliss

Author Affiliations

Donald E. Bliss was Associate Plant Pathologist in the Experiment Station.

Publication Information

Hilgardia 16(2):15-124. DOI:10.3733/hilg.v16n02p015. March 1944.

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Abstract does not appear. First page follows.


The importance of omphalia root rot (9),4 or decline disease,5 to the date industry lies principally in the fact that affected areas are increasing both in size and in number. About 1 per cent of the total acreage devoted to date culture in the Coachella Valley of California has become affected, and the annual loss in fruit production from this source at the present time may approach 100,000 pounds. With the exception of fruit spoilage, omphalia root rot is the most destructive fungus disease of date palms in California. Because this disease is comparatively new to science and because only a few of the date gardens are affected, the menace which it presents is as yet not fully appreciated. If one may judge by the present condition of certain plantings, however, it could, over a period of many years, become a limiting factor in the date industry.

Since certain date growers are urging control of omphalia root rot through regulation of planting stock, it is desirable to publish at this time a comprehensive report on the investigations of this disease, covering a period of fifteen years. Several preliminary papers (4), (5), (6), (7), (9), (10), (11) have appeared, but there are extensive experimental data and numerous illustrations not heretofore published. With special emphasis on these new data, this paper presents a summary of present knowledge concerning the omphalia root rot.


From the information now available, it seems that omphalia root rot was unknown before 1921, when one stunted palm was noticed. Little attention was given the matter until other, near-by palms showed a similar tendency. By 1927 there was evidence that palms previously normal in appearance had lost vigor and had become worthless. The trouble was first called to the attention of the University of California Citrus Experiment Station by officials of the United States Date Garden, Indio, California.

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Bliss D. 1944. Omphalia root rot of the date palm. Hilgardia 16(2):15-124. DOI:10.3733/hilg.v16n02p015
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