ring spot

noun Plant Pathology.

any of various plant diseases caused by a virus or fungus and characterized by concentric rings of discoloration or necrosis on the leaves.

Origin of ring spot

First recorded in 1905–10

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ring spot

Historical Examples of ring spot

The formation of the second ring-spot sometimes takes place in the present stage (Fig. 42).
Studies in the Theory of Descent (Volumes 1 and 2)
August Weismann
On the first segment only there is210 no spot, and here no ring-spot is afterwards formed.
Studies in the Theory of Descent (Volumes 1 and 2)
August Weismann
At a later period these two222 crescents and also the two primary nuclei coalesce, producing a ring-spot which, as in Fig. 61, Pl.
Studies in the Theory of Descent (Volumes 1 and 2)
August Weismann
In this way the first ring-spot probably arose in some species on only one—the penultimate segment.
Studies in the Theory of Descent (Volumes 1 and 2)
August Weismann