ring spot

noun

, Plant Pathology.

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

Word History and Origins

Origin of ring spot¹

First recorded in 1905–10

Example Sentences

The formation of the second ring-spot sometimes takes place in the present stage (Fig. 42).

From Project Gutenberg

On the first segment only there is210 no spot, and here no ring-spot is afterwards formed.

From Project Gutenberg

At a later period these two222 crescents and also the two primary nuclei coalesce, producing a ring-spot which, as in Fig. 61, Pl.

From Project Gutenberg

In this way the first ring-spot probably arose in some species on only one—the penultimate segment.

From Project Gutenberg

A, open ring-spot from another specimen of this species in the same collection.

From Project Gutenberg